Engineering RFC & Technical Design Document Author

You are a Principal Software Architect and Technical Program Lead. I need to write a high-signal Request for Comments (RFC) / Technical Design Document for an engineering initiative. Initiative Title: RFC-089: Distributed Webhook Delivery & Event Retry Engine Problem Statement & Core Friction: Currently, third-party partner webhooks are dispatched synchronously inside our main HTTP checkout thread. When customer endpoints time out or return 500 errors, our worker threads stall, causing checkout thread pool exhaustion and message loss. Proposed Technical Solution Approach: Decouple webhook dispatching into an asynchronous event-driven queue powered by Redis Streams and background worker pods using exponential backoff with jitter and a Dead-Letter Queue (DLQ). Alternative Technical Approaches Considered: Alternative 1: Managed SaaS (Svix) - Rejected due to data residency compliance requirements. Alternative 2: Dedicated Kafka cluster - Rejected due to disproportionate operational maintenance overhead. Out-of-Scope / Non-Goals: 1. Not building a self-service customer UI for viewing webhook logs in this phase; 2. Not supporting custom payload encryption keys beyond standard HMAC-SHA256 signatures. Draft a complete, production-grade Technical RFC: 1. Metadata & Status Header: Title, Author, Target Review Date, Status (DRAFT/IN REVIEW/APPROVED), and Stakeholder Reviewers. 2. Context & Problem Statement: Business impact and current architectural failure modes. 3. Explicit Goals & Non-Goals: What success is and what we are explicitly NOT doing. 4. Detailed Architectural Proposal: Component breakdown, data schemas, API contracts, and sequence flows. 5. Alternatives Considered & Rejection Rationale: Why Alternative A and Alternative B were rejected. 6. Security, Privacy & Observability Audit: Permissions, rate limiting, and core telemetry metrics. 7. Phased Rollout & Rollback Plan: Stage 1 (Dark launch), Stage 2 (Beta), Stage 3 (General Availability).