diff --git a/platform/internal/scheduler/scheduler.go b/platform/internal/scheduler/scheduler.go
index a23092cb..c00881d2 100644
--- a/platform/internal/scheduler/scheduler.go
+++ b/platform/internal/scheduler/scheduler.go
@@ -80,7 +80,16 @@ func (s *Scheduler) Start(ctx context.Context) {
 // tick queries all due schedules and fires each in a goroutine.
 // Waits for all goroutines to finish before returning so the next tick
 // doesn't re-fire schedules whose next_run_at hasn't been updated yet.
+//
+// Heartbeat is called at three points to keep /admin/liveness fresh during
+// long-running fires (some prompts take minutes — without these heartbeats
+// the scheduler looks "stale" the whole time it's working):
+//   - immediately on entering tick (proves we're past the ticker.C wait)
+//   - inside each per-fire goroutine (every fire bumps the heartbeat)
+//   - implicitly via the post-tick heartbeat in Start()
 func (s *Scheduler) tick(ctx context.Context) {
+	supervised.Heartbeat("scheduler")
+
 	rows, err := db.DB.QueryContext(ctx, `
 		SELECT id, workspace_id, name, cron_expr, timezone, prompt
 		FROM workspace_schedules
@@ -107,7 +116,15 @@ func (s *Scheduler) tick(ctx context.Context) {
 		go func(s2 scheduleRow) {
 			defer wg.Done()
 			defer func() { <-sem }()
+			defer func() {
+				if r := recover(); r != nil {
+					log.Printf("Scheduler: PANIC firing '%s' on workspace %s — recovered: %v",
+						s2.Name, s2.WorkspaceID, r)
+				}
+			}()
+			supervised.Heartbeat("scheduler")
 			s.fireSchedule(ctx, s2)
+			supervised.Heartbeat("scheduler")
 		}(sched)
 	}
 	if err := rows.Err(); err != nil {