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.