Durable Objects map a name or ID to a globally unique, single-threaded actor with private SQLite storage. They fit per-room, per-user, per-tenant, and per-run coordination boundaries; the real design question is where the object key belongs.
PartyKit concentrates WebSocket coordination in room-keyed stateful servers for multiplayer and presence, while durable documents, authorization, hibernation, and platform ownership still need explicit design.
D1 is Cloudflare's serverless SQLite database that binds directly to Workers, supports full SQL (JOINs, transactions), and handles automatic backups. It's well-suited for small-to-medium relational data needs — NobodyClimb uses it as its primary database.
KV is Cloudflare's globally distributed key-value store. Reads are served from the nearest edge node with extremely low latency. It's ideal for caching, feature flags, and ephemeral data — but writes are eventually consistent.
Hono is a web framework designed specifically for edge runtimes like Cloudflare Workers, Deno, and Bun. It's an order of magnitude lighter than Express, natively supports Web Standard APIs, and is the go-to choice for edge environments.