Overview: The system must be architected to meet enterprise CPaaS performance. Post award of project you will be shared a GitHub Repo update to be pushed there only. The scope includes backend API development, database schema design, & webhook hooks. The service must be built as a extension to existing service to ensure seamless, scalable, and repeatable integration into the main platform. 1. API & Webhooks for Clients • Public API endpoints for sending campaigns, managing templates, and fetching reports. • Webhook support for: • Delivery receipts (DLRs) • Incoming messages/user replies • Sustain minimum 500–1,000 send requests/sec under normal load. • Burst handling up to 3,000 TPS with graceful queuing (no message loss). 2. Integration Layer • Built-in connectors for MoEngage, Webengage, CleverTap, and other CRMs. • Ability to easily add more integrations later. • Queue Processing SLA: - Campaign enqueue latency: < 200 ms per batch. - Worker dequeue + dispatch latency: < 1 second under steady load. • Delivery Pipeline SLA: - Status callback processing: < 2 seconds end‑to‑end. • Horizontal Scaling Expectation: - Architecture must allow stateless API scaling. - Queue workers must scale independently. - Database read/write contention mitigation strategy required. • Reliability Targets: - Zero message loss guarantee with idempotent retry logic. - Queue durability with persistence verification. • Monitoring Metrics: - TPS tracking - Queue lag - Worker throughput - API response time - Failure rate alerts