SAYOMIYORI

Django for ORM-heavy domain logic + FastAPI for async notification consumer — each framework where it's strongest. RabbitMQ topic exchange decouples writes from delivery.

Celery + Redis broker for fire-and-forget delivery. Circuit breaker prevents hammering dead endpoints. HMAC + idempotency at infra layer, not business logic.

Redis Pub/Sub over in-memory — scaling to N replicas is transparent. WS auth via query param because browsers don't support custom headers on handshake.

Async SQLAlchemy 2 + asyncpg — bottleneck is I/O. Prometheus from day one — errors visible in dashboard before the first bug report.

Kafka as the single source of truth for event ordering. gRPC for internal high-throughput ingestion, REST for external clients. MinIO stores raw events — PostgreSQL stores only enriched, queryable state.

pgvector over dedicated vector DBs — keeps the stack simple while supporting semantic search. Redis semantic cache at cosine ≥0.95 cuts LLM calls on repeated queries. MCP server exposes tools to any compatible agent.

Token rotation on every refresh — stolen refresh tokens expire on next use. TOTP secret stored encrypted; audit log is append-only. Rate limiting at Redis layer, not application layer — survives restarts.

ClickHouse for logs — columnar storage gives 10-100x faster aggregations vs PostgreSQL at scale. Redis Streams as ingestion buffer absorb bursts before ClickHouse write. WebSocket live tail is read-only — no polling.

LoRA trains only 1% of parameters — fine-tuning on consumer hardware in minutes. ONNX export after training removes PyTorch runtime from serving path — 3-5x latency improvement. MinIO versioning enables instant model rollback.