diff --git a/backend/app/models.py b/backend/app/models.py
index e97ff49..657a5ff 100644
--- a/backend/app/models.py
+++ b/backend/app/models.py
@@ -313,6 +313,8 @@ class JobStatus(str, enum.Enum):
     TODO = "todo"
     SUBMITTED = "submitted"
     DONE = "done"
+    TO_CANCEL = "to_cancel"
+    CANCELLED = "cancelled"
     FAILED = "failed"
 
 
diff --git a/backend/app/routers/processing.py b/backend/app/routers/processing.py
index 68017f5..4658f9a 100644
--- a/backend/app/routers/processing.py
+++ b/backend/app/routers/processing.py
@@ -80,6 +80,10 @@ def update_jobs_status(payload: JobsUpdate, db: Session = Depends(get_db)):
 
         raise HTTPException(status_code=404, detail="Job not found")
 
+    # If status is being updated to "cancelled"
+    if payload.status == "cancelled":
+        job.slurm_id = None
+
     # Update the status
     job.status = payload.status
     job.slurm_id = payload.slurm_id
@@ -93,3 +97,23 @@ def update_jobs_status(payload: JobsUpdate, db: Session = Depends(get_db)):
 
     # Return the updated job's info as response
     return JobsUpdate(job_id=job.id, status=job.status, slurm_id=job.slurm_id)
+
+
+def cleanup_cancelled_jobs(db: Session):
+    from datetime import datetime
+    from datetime import timedelta
+
+    """Delete jobs in 'cancelled' state for more than 2 hours."""
+    cutoff = datetime.now() - timedelta(hours=2)
+    print(
+        f"Cleaning up cancelled jobs older than {cutoff} "
+        f"(current time: {datetime.now()})"
+    )
+    old_jobs = (
+        db.query(JobModel)
+        .filter(JobModel.status == "cancelled", JobModel.updated_at < cutoff)
+        .all()
+    )
+    for job in old_jobs:
+        db.delete(job)
+    db.commit()
diff --git a/backend/main.py b/backend/main.py
index e0fbb06..328c368 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -122,6 +122,20 @@ if environment == "dev":
         ssl_heidi.generate_self_signed_cert(cert_path, key_path)
 
 
+def cleanup_job_loop():
+    import time
+    from app.dependencies import get_db
+    from app.routers.processing import cleanup_cancelled_jobs
+
+    while True:
+        db = next(get_db())
+        try:
+            cleanup_cancelled_jobs(db)
+        finally:
+            db.close()
+        time.sleep(3600)  # every hour
+
+
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     print("[INFO] Running application startup tasks...")
@@ -174,6 +188,12 @@ async def lifespan(app: FastAPI):
 
                 load_slots_data(db)
 
+        from threading import Thread
+
+        # Start cleanup in background thread
+        thread = Thread(target=cleanup_job_loop, daemon=True)
+        thread.start()
+
         yield
     finally:
         db.close()