Immich is a high-performance, self-hosted photo and video management platform composed of a NestJS backend server, a SvelteKit SPA frontend, a Python FastAPI machine-learning service, a Flutter mobile client (iOS/Android), a CLI tool, and a TypeScript SDK. The server orchestrates asset ingestion, metadata extraction (EXIF, OCR, facial recognition, CLIP embeddings), video transcoding (HLS), and background job processing via BullMQ/Redis, with PostgreSQL (Kysely ORM + vector extensions for smart search) as the primary data store. The ML service provides ONNX-based inference for CLIP visual/textual embeddings, face detection/recognition (InsightFace), and OCR (RapidOCR), supporting multiple hardware accelerators (CUDA, ROCm, OpenVINO, ARM NN, RKNN). The architecture uses a multi-worker process model (API, microservices, maintenance) managed by a main process that handles lifecycle and restarts. Key data flows include: mobile/web upload → asset processing pipeline → metadata extraction → ML inference → search indexing, with real-time sync via WebSocket/Redis adapter and a full incremental sync API for mobile clients. The codebase demonstrates strong engineering practices: comprehensive repository pattern with 50+ repositories, extensive medium/integration test suites, schema migrations managed via Kysely SQL tools, OpenAPI-driven SDK generation for both TypeScript and Dart, and a plugin system using Extism WASM.