Technical Audit
Summary of Scope & Gaps
Section titled “Summary of Scope & Gaps”CF Messenger is a high-fidelity demonstration of Cloudflare edge primitives. While it excels at low-latency, global WebSockets, certain production-grade features are intentionally deferred for the POC.
Known Limitations & Failure Modes
Section titled “Known Limitations & Failure Modes”- Message Durability (Improved): ChatRoom DOs flush to disk every 1 second. While suitable for demos, it is not fully ACID compliant; a crash could lose up to 1s of data.
- Session Expiry UX: Tokens expire after 20 minutes. Without auto-refresh modals, users may experience abrupt disconnections.
- Rate Limit Drift: Durable Object counters reset on rare reroutes. KV mirrors reduce this drift but do not guarantee absolute enforcement.
- Presence Drift: SESSION_KV TTLs can expire while sockets remain open; the worker forces disconnects when tokens become invalid.
- DO Migration Loss: Deploying new Durable Object class definitions clears in-memory buffers unless state is persisted to KV/D1.
Path to Production
Section titled “Path to Production”To transition this stack from a demo to a production-ready application, the following work is required:
- Durability: Persist message buffers to Cloudflare R2 or D1, add deduplication logic, and replay buffers during warm-ups.
- Offline Delivery: Integrate Cloudflare Queues to buffer and retry messages when clients reconnect.
- Hardened Security: Rotate secrets automatically and encrypt Durable Object/KV buffers at rest using AES-256-GCM.
- Compliance Automation: Implement a full Deletion API, enforce strict retention policies, and enable Logpush for audit trails.
Observability & Analytics
Section titled “Observability & Analytics”The system utilises a dual-layered approach to monitor both performance and business logic:
Frontend: Web Analytics
Section titled “Frontend: Web Analytics”Privacy-first, cookie-less tracking of Real User Monitoring (RUM) metrics (LCP, FID, CLS) via a lightweight JavaScript beacon.
Backend: Workers Analytics Engine
Section titled “Backend: Workers Analytics Engine”High-cardinality, time-series logging of custom application events, such as login_success and ai_invocation, enabling SQL-based querying of application health directly from the Cloudflare Dashboard.
This audit ensures stakeholders understand both the immense capabilities and the deliberate constraints of the current architecture.