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Answer-first: Architecture Decision Records (ADRs) provide an immutable, version-controlled record of structural choices. This chapter documents all 24 production ADRs covering database selection (PostgreSQL + JSONB), messaging (Kafka), monorepo governance (Rush), framework (Kratos v2), and authentication (BFF + HttpOnly cookies).
Summary of Key Production ADRs
| ADR # | Decision Title | Selected Option | Key Trade-Off Rationale |
|---|---|---|---|
| ADR-001 | Primary Backend Language | Golang 1.25+ | Sub-millisecond startup, low memory footprint, high concurrency goroutines. |
| ADR-002 | Microservice Framework | Kratos v2 | Native Protobuf annotations, Google Wire compile-time DI, Clean Architecture. |
| ADR-003 | Monorepo Tooling | Microsoft Rush + PNPM | Strict symlink isolation, phantom dependency elimination, polyglot support. |
| ADR-004 | Primary Database | PostgreSQL (JSONB) | ACID compliance, JSONB GIN indexing for dynamic E-Commerce attributes. |
| ADR-005 | Event Streaming | Apache Kafka | High-throughput durable event log, replayability for new microservices. |
| ADR-006 | Inter-Service Transport | gRPC / Protobuf | Binary payload efficiency, type-safe API contracts, auto-generated SDKs. |
| ADR-007 | Client Gateway | grpc-gateway | Zero-maintenance REST/JSON exposure from existing Protobuf definitions. |
| ADR-008 | Distributed Transactions | Saga + Outbox | Eliminates blocking 2-Phase Commit locks while ensuring eventual consistency. |