02 · SYSTEM MONITORINGMONITORING
Sentinel
Startup-ready multi-tenant API monitor with automated Celery checks and Slack/Discord alerting.
METRIC 01Real-time endpoint down alerts dispatched within 150ms.
METRIC 02Multi-tenant user profiles secured via JWT authentication.
METRIC 03Implicit setInterval frontend polling for zero UI layout shift.
API downtime or slow responses lead to user churn. Startups need immediate alerts without the high licensing cost of enterprise APM tools.
DECISION 01
Celery Task Queue + Redis Broker
Alternative Evaluated:
Asyncio task loops inside FastAPI
Decision Reason:
Guarantees scheduling accuracy and isolates long-running HTTP polling requests outside the main API web thread pool, preventing server blockages.
Trade-off: Adds operational dependency on Redis and Celery processes, managed via container orchestrations.
Attempted Strategy
Originally built the database schema without proper user boundaries and isolated connections.
Observed Symptom
Database locks and leakage of endpoint alerts occurred between test tenant accounts under heavy simulated traffic.
Resolution & Fix
Secured database queries by implementing strict JWT middleware locks using SQLAlchemy dependencies binding operations directly to authenticated session contexts.
PythonFastAPICeleryRedisNode.jsReact 18PostgreSQL