BACKLOG.md

@@ -257,9 +257,9 @@ Split (issue #11 closed) into two independently-demoable slices per §13 — the
 
 **Outcome:** Traces span portal → BFF → Domain → ACL → OpenZaak and portal → BFF → Domain → Flowable. Grafana dashboards pre-built for golden signals.
 
-### S-17 · Quartz.NET scheduler — herregistratie reminder sweep
+### S-17 · Quartz.NET scheduler — herregistratie reminder sweep ✅
 
-**Outcome:** Nightly job that finds entries within 90 days of expiry and emits a domain event. (No outbound notification in v1 — logged.)
+**Outcome:** Daily Quartz.NET cron job finds inscriptions within 90 days of their herregistratie deadline and reminds each (flag on the aggregate + log). No outbound notification and no domain event in v1 — the reminder is the persisted flag, surfaced on the read model (ADR-0022, #120). Quartz fires time-triggered sweeps; the existing pumps stay as queue-drainers.
 
 ---
 

docs/architecture/adr-0022-quartz-scheduler.md

@@ -0,0 +1,79 @@
+# ADR-0022: Quartz.NET for time-triggered fleet sweeps
+
+- **Status:** Accepted
+- **Date:** 2026-07-23
+- **Deciders:** Respellion engineering
+- **Slice:** S-17 (#18) · **Proposal issue:** #120
+
+## Context
+
+A BIG inscription is valid for a fixed term; before it lapses the zorgprofessional
+must herregistreren. S-17 adds a **herregistratie reminder sweep**: once a day,
+scan the register for inscriptions whose deadline is within the reminder window and
+remind each one.
+
+The Domain Service already runs periodic background work — `OpenZaakJobPump`,
+`BeoordelingEscalatiePump`, `RegistratieVerlopenPump`. Those are **continuous job
+pollers**: they drain Flowable's external-task/job queues at-least-once, picking up
+work as soon as it is parked, on a short poll interval. The reminder sweep is a
+different shape of work: **time-triggered**, once a day, over our own store — there
+is no queue to drain and no "as soon as possible" requirement.
+
+The PRD already names the scheduler component: "Scheduler (Quartz.NET): fleet-wide
+sweeps (expiry, reminders)" (§39, §94). Adding Quartz.NET is nonetheless a new
+dependency, so this decision is recorded before the code lands (CLAUDE.md §14).
+
+## Decision
+
+**Use Quartz.NET for time-triggered fleet sweeps, starting with the herregistratie
+reminder sweep. Leave the existing pumps as `BackgroundService` job pollers.**
+
+- `HerregistratieReminderJob` (a Quartz `IJob`) is fired by a cron trigger — daily
+  at 03:00 by default, overridable with `Quartz__Cron`. It is a thin shell: it
+  resolves the pure `HerregistratieReminderSweep` (application layer) and logs how
+  many reminders went out.
+- The sweep's rule lives in the domain: `Registration.HerregistratieReminderDue(asOf)`,
+  which the store query and the sweep both build on. The sweep marks each reminded
+  inscription (`HerregistratieReminderVerstuurd`), so a re-fire reminds no one twice
+  (§8.6).
+
+Two options were rejected:
+
+1. **A `BackgroundService` with a 24h `Task.Delay`.** No new dependency, but it
+   drifts to process-start time, has no cron/misfire semantics, and contradicts the
+   PRD's named component. A daily "run at 03:00" is exactly what cron scheduling is
+   for.
+2. **Migrating the three pumps onto Quartz too, for one mechanism.** Rejected: the
+   pumps are not schedulers. Forcing a "run at time T" tool onto "drain this queue
+   continuously" work is churn and a boundary change for negative benefit. The
+   teachable distinction is worth keeping: **pumps drain queues; Quartz fires
+   sweeps.**
+
+## Consequences
+
+**Positive**
+
+- Cron scheduling with restart-stable timing and misfire handling, for free.
+- The reminder rule is one domain method, reused by the store query and the sweep;
+  the scheduler owns none of the policy.
+- The reference app now demonstrates the intended Scheduler component.
+
+**Negative / costs**
+
+- One new dependency (`Quartz`, `Quartz.Extensions.Hosting`) in the Domain Service.
+- Two periodic-work mechanisms coexist (pumps + Quartz). Deliberate — they model
+  two genuinely different concerns, documented here.
+
+**Follow-up**
+
+- The validity term (5 years) and reminder lead time (16 weeks) are domain
+  calibration knobs; promote them to beheer config (S-15) if a demo needs them
+  per-catalogus.
+- The Quartz job stores its schedule in RAM (`RAMJobStore`); a persistent/clustered
+  store is a later concern if the Domain Service is scaled out.
+
+## Coupling rules touched (CLAUDE.md §8)
+
+None. Quartz is internal to the Domain Service and drives an application use case
+over the store port. No ZGW or Flowable coupling is added; the sweep talks to no
+peer module.

docs/demo-script.md

@@ -5,6 +5,35 @@ copy-pasteable walkthrough against a local `make up` stack.
 
 ---
 
+## S-17 — herregistratie reminder sweep on a Quartz cron (#18, ADR-0022)
+
+**Outcome:** an inscription (INGESCHREVEN) now carries the moment it was entered in the register, from
+which its herregistratie deadline is derived (inscription + 5-year validity). A **Quartz.NET** cron job
+in the Domain Service sweeps once a day (03:00, overridable via `Quartz__Cron`): every inscription
+inside the 90-day window before its deadline is flagged `HerregistratieReminderVerstuurd` and logged.
+The sweep is idempotent — a re-fire reminds no one twice — and is a deliberately different mechanism
+from the queue-draining pumps (Quartz fires time-triggered sweeps; pumps drain Flowable queues,
+ADR-0022). There is no outbound notification in v1: the reminder is the flag on the aggregate plus a
+log line.
+
+```bash
+# 1. The domain unit tests prove the rule and the sweep end to end (rule → store query → sweep):
+cd services/domain && dotnet test Big.Tests/Big.Tests.csproj \
+  --filter "FullyQualifiedName~Herregistratie|FullyQualifiedName~ReminderSweep"
+#    → the reminder is due once the 90-day window opens, not before; a reminded inscription is skipped
+#      on the next sweep; the sweep flags + persists every due inscription and returns their ids.
+
+# 2. The read model surfaces the deadline once a registration is approved — the field the sweep acts on:
+curl -s localhost:8000/registrations/<id> | jq '{status, herregistratieVoor, herregistratieReminderVerstuurd}'
+#    → after approval: herregistratieVoor is inscription + 5 years; the flag flips true once swept.
+```
+
+**The path:** `Registration.Approve(now)` stamps `IngeschrevenOp` → daily Quartz `HerregistratieReminderJob`
+→ `HerregistratieReminderSweep` → `IRegistrationStore.FindDueForHerregistratieReminderAsync` (filtered by
+the aggregate's own `HerregistratieReminderDue` rule) → `MarkHerregistratieReminderVerstuurd` + log.
+
+---
+
 ## S-B04 — `make local` completes the whole flow with no manual seeding (#110, ADR-0020)
 
 **Outcome:** the host-browser stack (`make local`) now self-seeds at bring-up — it publishes the BIG

services/domain/Big.Api/Big.Api.csproj

@@ -5,6 +5,10 @@
     <ProjectReference Include="..\Big.Infrastructure\Big.Infrastructure.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Quartz.Extensions.Hosting" Version="3.18.2" />
+  </ItemGroup>
+
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
     <Nullable>enable</Nullable>

services/domain/Big.Api/Program.cs

@@ -1,6 +1,7 @@
 using Big.Application;
 using Big.Domain;
 using Big.Infrastructure;
+using Quartz;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -15,6 +16,10 @@ builder.Services.AddSingleton(sp => sp.GetRequiredService<IConfiguration>()
 // The in-memory registration store is shared between the submit endpoint and the worker (ADR-0009).
 builder.Services.AddSingleton<IRegistrationStore, InMemoryRegistrationStore>();
 
+// The system clock, injected wherever a use case needs "now" (e.g. stamping the inscription moment
+// on approval, S-17). Injected as TimeProvider so tests can substitute a fixed clock.
+builder.Services.AddSingleton(TimeProvider.System);
+
 // The Workflow Client is one type behind two ports (start side + worker side); both resolve to the
 // same HttpClient-backed implementation — the only code that talks to Flowable (§8.2).
 builder.Services.AddHttpClient<FlowableWorkflowClient>();
@@ -36,6 +41,7 @@ builder.Services.AddScoped<OpenZaakJobProcessor>();
 builder.Services.AddScoped<BeoordelingEscalatieProcessor>();
 builder.Services.AddScoped<ExpireRegistrationWorker>();
 builder.Services.AddScoped<RegistratieVerlopenProcessor>();
+builder.Services.AddScoped<HerregistratieReminderSweep>();
 
 // The hosted external-task job worker polls Flowable and drives OpenZaakAanmaken to completion.
 builder.Services.AddHostedService<OpenZaakJobPump>();
@@ -46,6 +52,19 @@ builder.Services.AddHostedService<BeoordelingEscalatiePump>();
 // parks and expires each lapsed registration to VERLOPEN (S-10a, ADR-0017).
 builder.Services.AddHostedService<RegistratieVerlopenPump>();
 
+// The herregistratie reminder sweep runs on a daily cron via Quartz.NET (S-17, ADR-0022) — a
+// time-triggered fleet sweep, deliberately a different mechanism from the queue-draining pumps above.
+// The cron is overridable with Quartz__Cron; it defaults to 03:00 daily.
+builder.Services.AddQuartz(q =>
+{
+    var jobKey = new JobKey("herregistratie-reminder");
+    q.AddJob<HerregistratieReminderJob>(jobKey);
+    q.AddTrigger(t => t
+        .ForJob(jobKey)
+        .WithCronSchedule(builder.Configuration["Quartz:Cron"] ?? "0 0 3 * * ?"));
+});
+builder.Services.AddQuartzHostedService(o => o.WaitForJobsToComplete = true);
+
 var app = builder.Build();
 
 app.MapGet("/health", () => "Healthy");
@@ -165,7 +184,8 @@ app.MapGet("/registrations/{id}", async (string id, IRegistrationStore store, Ca
     return registration is null
         ? Results.NotFound()
         : Results.Ok(new RegistrationResponse(
-            registration.Id.ToString(), registration.Status.ToString(), registration.ZaakUrl?.ToString()));
+            registration.Id.ToString(), registration.Status.ToString(), registration.ZaakUrl?.ToString(),
+            registration.HerregistratieVoor?.ToString("O"), registration.HerregistratieReminderVerstuurd));
 });
 
 await app.RunAsync();
@@ -178,6 +198,11 @@ public sealed record WithdrawRequest(string Bsn);
 
 public sealed record ProvideDocumentsRequest(string Bsn, string ContentBase64, string? FileName = null, string? ContentType = null);
 
-public sealed record RegistrationResponse(string RegistrationId, string Status, string? ZaakUrl);
+public sealed record RegistrationResponse(
+    string RegistrationId,
+    string Status,
+    string? ZaakUrl,
+    string? HerregistratieVoor = null,
+    bool HerregistratieReminderVerstuurd = false);
 
 public partial class Program;

services/domain/Big.Application/ApproveRegistration.cs

@@ -12,7 +12,7 @@ public sealed record ApproveRegistrationCommand(RegistrationId RegistrationId);
 /// zaak status is the projection's source of truth (it flows back over NRC); the aggregate transition
 /// keeps the domain's own view consistent.
 /// </summary>
-public sealed class ApproveRegistration(IRegistrationStore store, IAclClient acl)
+public sealed class ApproveRegistration(IRegistrationStore store, IAclClient acl, TimeProvider clock)
 {
     public async Task HandleAsync(ApproveRegistrationCommand command, CancellationToken ct = default)
     {
@@ -30,7 +30,7 @@ public sealed class ApproveRegistration(IRegistrationStore store, IAclClient acl
                 $"Registration {command.RegistrationId} has no zaak yet; it cannot be approved.");
 
         await acl.ApproveZaakAsync(registration.ZaakUrl, ct);
-        registration.Approve();
+        registration.Approve(clock.GetUtcNow());
         await store.SaveAsync(registration, ct);
     }
 }

services/domain/Big.Application/BeoordeelRegistratie.cs

@@ -25,7 +25,7 @@ public sealed record BeoordeelRegistratieCommand(RegistrationId RegistrationId,
 /// decisions are idempotent — a repeated or redelivered decision that matches the current terminal
 /// state is a no-op, so the ACL is not called and the task not completed twice.
 /// </summary>
-public sealed class BeoordeelRegistratie(IRegistrationStore store, IAclClient acl, IUserTaskClient tasks)
+public sealed class BeoordeelRegistratie(IRegistrationStore store, IAclClient acl, IUserTaskClient tasks, TimeProvider clock)
 {
     public async Task HandleAsync(BeoordeelRegistratieCommand command, CancellationToken ct = default)
     {
@@ -44,7 +44,7 @@ public sealed class BeoordeelRegistratie(IRegistrationStore store, IAclClient ac
                     throw new InvalidOperationException(
                         $"Registration {command.RegistrationId} has no zaak yet; it cannot be approved.");
                 await acl.ApproveZaakAsync(registration.ZaakUrl, ct);
-                registration.Approve();
+                registration.Approve(clock.GetUtcNow());
                 break;
 
             case BeoordelingsBesluit.Afwijzen:

services/domain/Big.Application/HerregistratieReminderSweep.cs

@@ -0,0 +1,30 @@
+using Big.Domain;
+
+namespace Big.Application;
+
+/// <summary>
+/// The herregistratie reminder sweep (S-17): find the inscriptions whose herregistratie deadline is
+/// within the reminder window and have not yet been reminded, mark each reminded, and persist it. Pure
+/// application logic over ports — it knows nothing of Quartz; the scheduled job that fires it on a cron
+/// lives in Infrastructure (mirroring how the pumps' processors are pure and the pump is the shell).
+/// Idempotent: <see cref="Registration.MarkHerregistratieReminderVerstuurd"/> drops an inscription from
+/// the next sweep's candidate set, so a re-fire reminds no one twice. Returns the reminded ids so the
+/// caller can observe the sweep's effect — the reminder itself is the flag persisted on the aggregate.
+/// </summary>
+public sealed class HerregistratieReminderSweep(IRegistrationStore store, TimeProvider clock)
+{
+    public async Task<IReadOnlyList<RegistrationId>> SweepAsync(CancellationToken ct = default)
+    {
+        var due = await store.FindDueForHerregistratieReminderAsync(clock.GetUtcNow(), ct);
+
+        var reminded = new List<RegistrationId>(due.Count);
+        foreach (var registration in due)
+        {
+            registration.MarkHerregistratieReminderVerstuurd();
+            await store.SaveAsync(registration, ct);
+            reminded.Add(registration.Id);
+        }
+
+        return reminded;
+    }
+}

services/domain/Big.Application/Ports.cs

@@ -107,6 +107,13 @@ public interface IRegistrationStore
     /// registration, or <c>null</c> if they have none in flight. Lets the self-service portal resume
     /// an existing registration after a refresh (S-26); terminal registrations are not resumed.</summary>
     Task<Registration?> FindOpenByBsnAsync(string bsn, CancellationToken ct = default);
+
+    /// <summary>The inscriptions whose herregistratie reminder is due as of <paramref name="asOf"/> and
+    /// not yet sent — the herregistratie reminder sweep's candidate set (S-17). The predicate is the
+    /// aggregate's own <see cref="Registration.HerregistratieReminderDue"/> rule, so the store never
+    /// duplicates the herregistratie policy.</summary>
+    Task<IReadOnlyList<Registration>> FindDueForHerregistratieReminderAsync(
+        DateTimeOffset asOf, CancellationToken ct = default);
 }
 
 /// <summary>

services/domain/Big.Domain/Registration.cs

@@ -92,11 +92,12 @@ public sealed class Registration
 
     /// <summary>
     /// Approve the registration — the behandelaar's decision to enter it in the register. Advances a
-    /// submitted or in-behandeling registration to <see cref="RegistrationStatus.Ingeschreven"/>.
-    /// Requires an opened zaak (the approval sets that zaak's status via the ACL); a registration that
-    /// has already been decided cannot be approved again.
+    /// submitted or in-behandeling registration to <see cref="RegistrationStatus.Ingeschreven"/> and
+    /// records <paramref name="ingeschrevenOp"/> as the moment of inscription, which starts the
+    /// herregistratie clock (S-17). Requires an opened zaak (the approval sets that zaak's status via
+    /// the ACL); a registration that has already been decided cannot be approved again.
     /// </summary>
-    public void Approve()
+    public void Approve(DateTimeOffset ingeschrevenOp)
     {
         if (ZaakUrl is null)
             throw new InvalidOperationException(
@@ -104,6 +105,54 @@ public sealed class Registration
 
         RequireOpenForDecision(nameof(Approve));
         Status = RegistrationStatus.Ingeschreven;
+        IngeschrevenOp = ingeschrevenOp;
+    }
+
+    // --- Herregistratie (S-17) — RED stubs, implemented in the green commit ---------------------
+
+    /// <summary>How long a BIG inscription stays valid before herregistratie is required.</summary>
+    // ponytail: fixed 5-year term — a calibration knob, not a config surface. If a demo needs it
+    // per-catalogus, promote it to policy passed in from the beheer config (S-15).
+    public static readonly TimeSpan HerregistratieGeldigheid = TimeSpan.FromDays(365 * 5);
+
+    /// <summary>How long before the deadline the herregistratie reminder is sent (S-17: 90 days).</summary>
+    // ponytail: fixed 90-day lead time — calibration knob; same promotion path as HerregistratieGeldigheid.
+    public static readonly TimeSpan Herinneringstermijn = TimeSpan.FromDays(90);
+
+    /// <summary>When the registration was entered in the register, once approved; the start of its
+    /// herregistratie clock. Null until it is <see cref="RegistrationStatus.Ingeschreven"/>.</summary>
+    public DateTimeOffset? IngeschrevenOp { get; private set; }
+
+    /// <summary>The date by which herregistratie must happen: inscription + validity. Null until
+    /// inscribed.</summary>
+    public DateTimeOffset? HerregistratieVoor =>
+        IngeschrevenOp is DateTimeOffset ingeschrevenOp ? ingeschrevenOp + HerregistratieGeldigheid : null;
+
+    /// <summary>Whether the herregistratie reminder has been sent for this inscription (S-17).</summary>
+    public bool HerregistratieReminderVerstuurd { get; private set; }
+
+    /// <summary>Whether, as of <paramref name="asOf"/>, this registration is due a herregistratie
+    /// reminder: it is inscribed, the reminder window before its deadline has opened, and it has not
+    /// already been reminded. Once inside the window it stays due until reminded (an overdue inscription
+    /// is still due). This is the single rule the store query and the sweep both build on.</summary>
+    public bool HerregistratieReminderDue(DateTimeOffset asOf) =>
+        Status == RegistrationStatus.Ingeschreven
+        && !HerregistratieReminderVerstuurd
+        && IngeschrevenOp is DateTimeOffset ingeschrevenOp
+        && asOf >= ingeschrevenOp + HerregistratieGeldigheid - Herinneringstermijn;
+
+    /// <summary>Record that the herregistratie reminder has been sent. Idempotent — a re-sweep is a
+    /// no-op (§8.6); only an inscribed registration can be reminded.</summary>
+    public void MarkHerregistratieReminderVerstuurd()
+    {
+        if (HerregistratieReminderVerstuurd)
+            return;
+
+        if (Status != RegistrationStatus.Ingeschreven)
+            throw new InvalidOperationException(
+                $"Registration {Id} is {Status}; only an INGESCHREVEN registration can be sent a herregistratie reminder.");
+
+        HerregistratieReminderVerstuurd = true;
     }
 
     /// <summary>

services/domain/Big.Infrastructure/Big.Infrastructure.csproj

@@ -19,6 +19,7 @@
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.0" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.0" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0" />
+    <PackageReference Include="Quartz" Version="3.18.2" />
   </ItemGroup>
 
 </Project>

services/domain/Big.Infrastructure/HerregistratieReminderJob.cs

@@ -0,0 +1,26 @@
+using Big.Application;
+using Microsoft.Extensions.Logging;
+using Quartz;
+
+namespace Big.Infrastructure;
+
+/// <summary>
+/// The Quartz job that fires the herregistratie reminder sweep on a cron schedule (S-17, ADR-0022).
+/// A deliberately thin shell — it resolves the pure <see cref="HerregistratieReminderSweep"/> (Quartz's
+/// MS-DI job factory gives each fire its own scope) and logs how many reminders went out; all the
+/// sweep logic is unit-tested in the application layer. Quartz drives this — rather than a
+/// BackgroundService poll loop like the pumps — because it is a time-triggered fleet sweep, not a
+/// queue to drain (the distinction recorded in ADR-0022). <see cref="DisallowConcurrentExecutionAttribute"/>
+/// stops a slow sweep overlapping the next fire against the shared store.
+/// </summary>
+[DisallowConcurrentExecution]
+public sealed class HerregistratieReminderJob(
+    HerregistratieReminderSweep sweep, ILogger<HerregistratieReminderJob> logger) : IJob
+{
+    public async Task Execute(IJobExecutionContext context)
+    {
+        var reminded = await sweep.SweepAsync(context.CancellationToken);
+        logger.LogInformation(
+            "Herregistratie-sweep voltooid: {Count} herinnering(en) verstuurd.", reminded.Count);
+    }
+}

services/domain/Big.Infrastructure/InMemoryRegistrationStore.cs

@@ -26,4 +26,9 @@ public sealed class InMemoryRegistrationStore : IRegistrationStore
     public Task<Registration?> FindOpenByBsnAsync(string bsn, CancellationToken ct = default)
         => Task.FromResult(_byId.Values.FirstOrDefault(r =>
             r.Bsn == bsn && r.Status is RegistrationStatus.Ingediend or RegistrationStatus.InBehandeling));
+
+    public Task<IReadOnlyList<Registration>> FindDueForHerregistratieReminderAsync(
+        DateTimeOffset asOf, CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<Registration>>(
+            _byId.Values.Where(r => r.HerregistratieReminderDue(asOf)).ToList());
 }

services/domain/Big.Tests/ApproveRegistrationTests.cs

@@ -19,7 +19,7 @@ public class ApproveRegistrationTests
         var acl = new FakeAclClient();
         var registration = WithZaak();
         store.Seed(registration);
-        var handler = new ApproveRegistration(store, acl);
+        var handler = new ApproveRegistration(store, acl, TimeProvider.System);
 
         await handler.HandleAsync(new ApproveRegistrationCommand(registration.Id));
 
@@ -36,7 +36,7 @@ public class ApproveRegistrationTests
     {
         var store = new FakeRegistrationStore();
         var acl = new FakeAclClient();
-        var handler = new ApproveRegistration(store, acl);
+        var handler = new ApproveRegistration(store, acl, TimeProvider.System);
 
         await Assert.ThrowsAsync<ArgumentNullException>(() => handler.HandleAsync(null!));
         Assert.Equal(0, acl.ApproveCallCount);
@@ -47,7 +47,7 @@ public class ApproveRegistrationTests
     {
         var store = new FakeRegistrationStore();
         var acl = new FakeAclClient();
-        var handler = new ApproveRegistration(store, acl);
+        var handler = new ApproveRegistration(store, acl, TimeProvider.System);
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(
             () => handler.HandleAsync(new ApproveRegistrationCommand(RegistrationId.New())));
@@ -62,7 +62,7 @@ public class ApproveRegistrationTests
         var acl = new FakeAclClient();
         var registration = Registration.Submit("123456782"); // no zaak yet
         store.Seed(registration);
-        var handler = new ApproveRegistration(store, acl);
+        var handler = new ApproveRegistration(store, acl, TimeProvider.System);
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(
             () => handler.HandleAsync(new ApproveRegistrationCommand(registration.Id)));
@@ -77,7 +77,7 @@ public class ApproveRegistrationTests
         var acl = new FakeAclClient();
         var registration = WithZaak();
         store.Seed(registration);
-        var handler = new ApproveRegistration(store, acl);
+        var handler = new ApproveRegistration(store, acl, TimeProvider.System);
 
         await handler.HandleAsync(new ApproveRegistrationCommand(registration.Id));
         await handler.HandleAsync(new ApproveRegistrationCommand(registration.Id));

services/domain/Big.Tests/BeoordeelRegistratieTests.cs

@@ -29,7 +29,7 @@ public class BeoordeelRegistratieTests
         var registration = WithZaak();
         store.Seed(registration);
         var tasks = TaskFor(registration);
-        var handler = new BeoordeelRegistratie(store, acl, tasks);
+        var handler = new BeoordeelRegistratie(store, acl, tasks, TimeProvider.System);
 
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Goedkeuren));
 
@@ -50,7 +50,7 @@ public class BeoordeelRegistratieTests
         var registration = WithZaak();
         store.Seed(registration);
         var tasks = TaskFor(registration);
-        var handler = new BeoordeelRegistratie(store, acl, tasks);
+        var handler = new BeoordeelRegistratie(store, acl, tasks, TimeProvider.System);
 
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Afwijzen));
 
@@ -69,7 +69,7 @@ public class BeoordeelRegistratieTests
         var registration = WithZaak();
         registration.TakeIntoBehandeling();
         store.Seed(registration);
-        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration));
+        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration), TimeProvider.System);
 
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Goedkeuren));
 
@@ -81,7 +81,7 @@ public class BeoordeelRegistratieTests
     {
         var store = new FakeRegistrationStore();
         var acl = new FakeAclClient();
-        var handler = new BeoordeelRegistratie(store, acl, new FakeUserTaskClient([]));
+        var handler = new BeoordeelRegistratie(store, acl, new FakeUserTaskClient([]), TimeProvider.System);
 
         await Assert.ThrowsAsync<ArgumentNullException>(() => handler.HandleAsync(null!));
         Assert.Equal(0, acl.ApproveCallCount);
@@ -93,7 +93,7 @@ public class BeoordeelRegistratieTests
     {
         var store = new FakeRegistrationStore();
         var acl = new FakeAclClient();
-        var handler = new BeoordeelRegistratie(store, acl, new FakeUserTaskClient([]));
+        var handler = new BeoordeelRegistratie(store, acl, new FakeUserTaskClient([]), TimeProvider.System);
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(() =>
             handler.HandleAsync(new BeoordeelRegistratieCommand(RegistrationId.New(), BeoordelingsBesluit.Goedkeuren)));
@@ -108,7 +108,7 @@ public class BeoordeelRegistratieTests
         var acl = new FakeAclClient();
         var registration = Registration.Submit("123456782"); // no zaak yet
         store.Seed(registration);
-        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration));
+        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration), TimeProvider.System);
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(() =>
             handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Goedkeuren)));
@@ -123,7 +123,7 @@ public class BeoordeelRegistratieTests
         var acl = new FakeAclClient();
         var registration = WithZaak();
         store.Seed(registration);
-        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration));
+        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration), TimeProvider.System);
 
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Goedkeuren));
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Goedkeuren));
@@ -139,7 +139,7 @@ public class BeoordeelRegistratieTests
         var acl = new FakeAclClient();
         var registration = WithZaak();
         store.Seed(registration);
-        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration));
+        var handler = new BeoordeelRegistratie(store, acl, TaskFor(registration), TimeProvider.System);
 
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Afwijzen));
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Afwijzen));
@@ -158,7 +158,7 @@ public class BeoordeelRegistratieTests
         var registration = WithZaak();
         store.Seed(registration);
         var tasks = new FakeUserTaskClient([]); // no open task for this registration
-        var handler = new BeoordeelRegistratie(store, acl, tasks);
+        var handler = new BeoordeelRegistratie(store, acl, tasks, TimeProvider.System);
 
         await handler.HandleAsync(new BeoordeelRegistratieCommand(registration.Id, BeoordelingsBesluit.Goedkeuren));
 

services/domain/Big.Tests/Fakes.cs

@@ -26,6 +26,11 @@ internal sealed class FakeRegistrationStore : IRegistrationStore
         => Task.FromResult(_byId.Values.FirstOrDefault(r =>
             r.Bsn == bsn && r.Status is RegistrationStatus.Ingediend or RegistrationStatus.InBehandeling));
 
+    public Task<IReadOnlyList<Registration>> FindDueForHerregistratieReminderAsync(
+        DateTimeOffset asOf, CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<Registration>>(
+            _byId.Values.Where(r => r.HerregistratieReminderDue(asOf)).ToList());
+
     public void Seed(Registration registration) => _byId[registration.Id] = registration;
 }
 
@@ -85,6 +90,13 @@ internal sealed class FakeUserTaskClient(IReadOnlyList<BeoordelingTask> open) :
     }
 }
 
+/// <summary>A <see cref="TimeProvider"/> pinned to a fixed instant, so time-based use cases (the
+/// herregistratie sweep, S-17) are deterministic without the TimeProvider.Testing package.</summary>
+internal sealed class FixedClock(DateTimeOffset now) : TimeProvider
+{
+    public override DateTimeOffset GetUtcNow() => now;
+}
+
 /// <summary>A fake ACL client that records the bsn it was asked to open a zaak for and returns a
 /// fixed zaak URL.</summary>
 internal sealed class FakeAclClient(Uri? zaakUrl = null) : IAclClient

services/domain/Big.Tests/HerregistratieReminderSweepTests.cs

@@ -0,0 +1,67 @@
+using Big.Application;
+using Big.Domain;
+
+namespace Big.Tests;
+
+// S-17 (#18): the sweep behind the Quartz job. It reminds every inscription whose herregistratie
+// reminder is due, marks each so a re-fire is a no-op (§8.6), and returns the reminded ids. Pure over
+// the store + an injected clock — no Quartz here.
+public class HerregistratieReminderSweepTests
+{
+    private static readonly DateTimeOffset Now = new(2026, 7, 23, 0, 0, 0, TimeSpan.Zero);
+
+    private static Registration Inscribed(string bsn, DateTimeOffset ingeschrevenOp)
+    {
+        var registration = Registration.Submit(bsn);
+        registration.AttachZaak(FakeAclClient.DefaultZaakUrl);
+        registration.Approve(ingeschrevenOp);
+        return registration;
+    }
+
+    // Inscribed exactly (geldigheid - herinneringstermijn) before Now: the reminder window is open.
+    private static Registration Due(string bsn)
+        => Inscribed(bsn, Now - Registration.HerregistratieGeldigheid + Registration.Herinneringstermijn);
+
+    [Fact]
+    public async Task Reminds_and_persists_every_due_inscription_and_returns_their_ids()
+    {
+        var store = new FakeRegistrationStore();
+        var a = Due("123456782");
+        var b = Due("111111110");
+        var freshlyInscribed = Inscribed("222222222", Now); // not yet in the window
+        store.Seed(a);
+        store.Seed(b);
+        store.Seed(freshlyInscribed);
+
+        var reminded = await new HerregistratieReminderSweep(store, new FixedClock(Now)).SweepAsync();
+
+        Assert.Equal(new HashSet<RegistrationId> { a.Id, b.Id }, reminded.ToHashSet());
+        Assert.True((await store.GetAsync(a.Id))!.HerregistratieReminderVerstuurd);
+        Assert.True((await store.GetAsync(b.Id))!.HerregistratieReminderVerstuurd);
+        Assert.False((await store.GetAsync(freshlyInscribed.Id))!.HerregistratieReminderVerstuurd);
+        Assert.Equal(2, store.SaveCount);
+    }
+
+    [Fact]
+    public async Task A_second_sweep_reminds_no_one_again()
+    {
+        var store = new FakeRegistrationStore();
+        store.Seed(Due("123456782"));
+        var sweep = new HerregistratieReminderSweep(store, new FixedClock(Now));
+
+        await sweep.SweepAsync();
+        var second = await sweep.SweepAsync();
+
+        Assert.Empty(second);
+        Assert.Equal(1, store.SaveCount); // only the first sweep persisted anything
+    }
+
+    [Fact]
+    public async Task Reminds_no_one_when_nothing_is_due()
+    {
+        var store = new FakeRegistrationStore();
+        store.Seed(Inscribed("123456782", Now)); // freshly inscribed — deadline is 5 years off
+
+        Assert.Empty(await new HerregistratieReminderSweep(store, new FixedClock(Now)).SweepAsync());
+    }
+}

services/domain/Big.Tests/InMemoryRegistrationStoreTests.cs

@@ -79,7 +79,7 @@ public class InMemoryRegistrationStoreTests
         switch (transition)
         {
             case nameof(Registration.Withdraw): registration.Withdraw(); break;
-            case nameof(Registration.Approve): registration.Approve(); break;
+            case nameof(Registration.Approve): registration.Approve(DateTimeOffset.UtcNow); break;
             case nameof(Registration.Reject): registration.Reject(); break;
             case nameof(Registration.Expire): registration.Expire(); break;
         }
@@ -96,4 +96,27 @@ public class InMemoryRegistrationStoreTests
 
         Assert.Null(await store.FindOpenByBsnAsync("123456782"));
     }
+
+    [Fact]
+    public async Task Finds_only_the_inscriptions_due_for_a_herregistratie_reminder()
+    {
+        var now = new DateTimeOffset(2026, 7, 23, 0, 0, 0, TimeSpan.Zero);
+        var store = new InMemoryRegistrationStore();
+
+        var due = Registration.Submit("123456782");
+        due.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
+        due.Approve(now - Registration.HerregistratieGeldigheid + Registration.Herinneringstermijn);
+        await store.SaveAsync(due);
+
+        var freshlyInscribed = Registration.Submit("111111110");
+        freshlyInscribed.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/def"));
+        freshlyInscribed.Approve(now);
+        await store.SaveAsync(freshlyInscribed);
+
+        await store.SaveAsync(Registration.Submit("222222222")); // still INGEDIEND — never inscribed
+
+        var result = await store.FindDueForHerregistratieReminderAsync(now);
+
+        Assert.Equal([due.Id], result.Select(r => r.Id).ToArray());
+    }
 }

services/domain/Big.Tests/RegistrationHerregistratieTests.cs

@@ -0,0 +1,90 @@
+using Big.Domain;
+
+namespace Big.Tests;
+
+// S-17 (#18): a BIG inscription is valid for a fixed term; before it lapses the zorgprofessional must
+// herregistreren. The aggregate records when it was inscribed, derives the herregistratie deadline, and
+// answers whether a reminder is due as of a given moment — the single rule the Quartz sweep and the
+// store query both build on. All arithmetic is against an explicit "now" so it is wall-clock-free.
+public class RegistrationHerregistratieTests
+{
+    private static readonly DateTimeOffset Now = new(2026, 7, 23, 0, 0, 0, TimeSpan.Zero);
+
+    // The moment the reminder window opens: inscribed exactly (geldigheid - herinneringstermijn) ago.
+    private static DateTimeOffset InscribedSoDueAt(DateTimeOffset asOf)
+        => asOf - Registration.HerregistratieGeldigheid + Registration.Herinneringstermijn;
+
+    private static Registration Inscribed(DateTimeOffset ingeschrevenOp)
+    {
+        var registration = Registration.Submit("123456782");
+        registration.AttachZaak(FakeAclClient.DefaultZaakUrl);
+        registration.Approve(ingeschrevenOp);
+        return registration;
+    }
+
+    [Fact]
+    public void Approving_records_the_inscription_moment_and_the_herregistratie_deadline()
+    {
+        var registration = Inscribed(Now);
+
+        Assert.Equal(Now, registration.IngeschrevenOp);
+        Assert.Equal(Now + Registration.HerregistratieGeldigheid, registration.HerregistratieVoor);
+    }
+
+    [Fact]
+    public void A_reminder_is_due_the_moment_the_window_before_the_deadline_opens()
+    {
+        var registration = Inscribed(InscribedSoDueAt(Now));
+
+        Assert.True(registration.HerregistratieReminderDue(Now));
+    }
+
+    [Fact]
+    public void A_reminder_is_not_yet_due_one_day_before_the_window_opens()
+    {
+        var registration = Inscribed(InscribedSoDueAt(Now) + TimeSpan.FromDays(1));
+
+        Assert.False(registration.HerregistratieReminderDue(Now));
+    }
+
+    [Fact]
+    public void A_registration_that_is_not_ingeschreven_is_never_due_and_has_no_deadline()
+    {
+        var registration = Registration.Submit("123456782"); // INGEDIEND, never inscribed
+
+        Assert.Null(registration.IngeschrevenOp);
+        Assert.Null(registration.HerregistratieVoor);
+        Assert.False(registration.HerregistratieReminderDue(Now));
+    }
+
+    [Fact]
+    public void A_reminded_registration_is_no_longer_due()
+    {
+        var registration = Inscribed(InscribedSoDueAt(Now));
+
+        registration.MarkHerregistratieReminderVerstuurd();
+
+        Assert.True(registration.HerregistratieReminderVerstuurd);
+        Assert.False(registration.HerregistratieReminderDue(Now));
+    }
+
+    [Fact]
+    public void Marking_the_reminder_sent_twice_is_idempotent()
+    {
+        var registration = Inscribed(InscribedSoDueAt(Now));
+
+        registration.MarkHerregistratieReminderVerstuurd();
+        registration.MarkHerregistratieReminderVerstuurd();
+
+        Assert.True(registration.HerregistratieReminderVerstuurd);
+    }
+
+    [Fact]
+    public void Marking_a_reminder_on_a_registration_that_is_not_ingeschreven_is_rejected()
+    {
+        var registration = Registration.Submit("123456782");
+
+        var ex = Assert.Throws<InvalidOperationException>(() => registration.MarkHerregistratieReminderVerstuurd());
+        Assert.Contains("INGESCHREVEN", ex.Message);
+    }
+}

services/domain/Big.Tests/RegistrationTests.cs

@@ -4,6 +4,9 @@ namespace Big.Tests;
 
 public class RegistrationTests
 {
+    // A fixed inscription moment for the approval tests; its exact value is irrelevant to them.
+    private static readonly DateTimeOffset Ingeschreven = new(2026, 1, 1, 0, 0, 0, TimeSpan.Zero);
+
     [Fact]
     public void Submitting_a_registration_starts_in_ingediend()
     {
@@ -103,7 +106,7 @@ public class RegistrationTests
         var registration = Registration.Submit("123456782");
         registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
 
-        registration.Approve();
+        registration.Approve(Ingeschreven);
 
         Assert.Equal(RegistrationStatus.Ingeschreven, registration.Status);
     }
@@ -113,7 +116,7 @@ public class RegistrationTests
     {
         var registration = Registration.Submit("123456782");
 
-        var ex = Assert.Throws<InvalidOperationException>(() => registration.Approve());
+        var ex = Assert.Throws<InvalidOperationException>(() => registration.Approve(Ingeschreven));
 
         Assert.Contains("no zaak", ex.Message, StringComparison.OrdinalIgnoreCase);
         Assert.Equal(RegistrationStatus.Ingediend, registration.Status);
@@ -124,9 +127,9 @@ public class RegistrationTests
     {
         var registration = Registration.Submit("123456782");
         registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
-        registration.Approve();
+        registration.Approve(Ingeschreven);
 
-        var ex = Assert.Throws<InvalidOperationException>(() => registration.Approve());
+        var ex = Assert.Throws<InvalidOperationException>(() => registration.Approve(Ingeschreven));
         Assert.Contains("only an INGEDIEND", ex.Message);
         Assert.Equal(RegistrationStatus.Ingeschreven, registration.Status);
     }
@@ -157,7 +160,7 @@ public class RegistrationTests
     {
         var registration = Registration.Submit("123456782");
         registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
-        registration.Approve();
+        registration.Approve(Ingeschreven);
 
         var ex = Assert.Throws<InvalidOperationException>(() => registration.TakeIntoBehandeling());
         Assert.Contains("only an INGEDIEND", ex.Message);
@@ -171,7 +174,7 @@ public class RegistrationTests
         registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
         registration.TakeIntoBehandeling();
 
-        registration.Approve();
+        registration.Approve(Ingeschreven);
 
         Assert.Equal(RegistrationStatus.Ingeschreven, registration.Status);
     }
@@ -218,7 +221,7 @@ public class RegistrationTests
         var approveEx = Assert.Throws<InvalidOperationException>(() =>
         {
             registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
-            registration.Approve();
+            registration.Approve(Ingeschreven);
         });
         Assert.Contains("IN_BEHANDELING", approveEx.Message);
 
@@ -277,7 +280,7 @@ public class RegistrationTests
     {
         var registration = Registration.Submit("123456782");
         registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
-        registration.Approve();
+        registration.Approve(Ingeschreven);
 
         var ex = Assert.Throws<InvalidOperationException>(() => registration.Withdraw());
         Assert.Contains("only an INGEDIEND", ex.Message);
@@ -336,7 +339,7 @@ public class RegistrationTests
     {
         var registration = Registration.Submit("123456782");
         registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
-        registration.Approve();
+        registration.Approve(Ingeschreven);
 
         var ex = Assert.Throws<InvalidOperationException>(() => registration.Expire());
         Assert.Contains("only an INGEDIEND", ex.Message);

services/domain/stryker-config.json

@@ -6,7 +6,8 @@
     "mutate": [
       "!**/OpenZaakJobPump.cs",
       "!**/BeoordelingEscalatiePump.cs",
-      "!**/RegistratieVerlopenPump.cs"
+      "!**/RegistratieVerlopenPump.cs",
+      "!**/HerregistratieReminderJob.cs"
     ],
     "thresholds": {
       "high": 95,

tests/acceptance/Steps/EenRegistratieBeoordelenSteps.cs

@@ -40,7 +40,7 @@ public sealed class EenRegistratieBeoordelenSteps
 
     [When("the behandelaar decides \"(.*)\"")]
     public async Task WhenTheBehandelaarDecides(string besluit)
-        => await new BeoordeelRegistratie(_store, _acl, _tasks).HandleAsync(
+        => await new BeoordeelRegistratie(_store, _acl, _tasks, TimeProvider.System).HandleAsync(
             new BeoordeelRegistratieCommand(_id, Enum.Parse<BeoordelingsBesluit>(besluit, ignoreCase: true)));
 
     [Then("the registration has status \"(.*)\"")]

tests/acceptance/Support/InMemoryDomainPorts.cs

@@ -221,4 +221,9 @@ public sealed class InMemoryRegistrationStore : IRegistrationStore
     public Task<Registration?> FindOpenByBsnAsync(string bsn, CancellationToken ct = default)
         => Task.FromResult(_byId.Values.FirstOrDefault(r =>
             r.Bsn == bsn && r.Status is RegistrationStatus.Ingediend or RegistrationStatus.InBehandeling));
+
+    public Task<IReadOnlyList<Registration>> FindDueForHerregistratieReminderAsync(
+        DateTimeOffset asOf, CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<Registration>>(
+            _byId.Values.Where(r => r.HerregistratieReminderDue(asOf)).ToList());
 }