#health-check

A Rust service that serves Indonesia's administrative regions — 38 provinces down to 83,768 villages, keyed by the official Ministry of Home Affairs codes — as four cascading lookups with search, so every address form in every project gets the same answer.

Three commands that build a full copy of production for one release — configuration from the repository, images from the registry, data from the latest backup — restore it in order, run the release's migrations against that data, and remove it without a trace.

An interactive Python script that proves an identity provider is ready for a client: it rehearses a full PKCE sign-in and sign-out like an application, then checks the tokens it receives against the provider's keys the way an application must.

A single Python script that proves S3-compatible storage is ready before an application depends on it, by using every bucket the way a real client does and catching the failures that return HTTP 200.

SMTP and IMAP credentials fail late and far from their cause: a reset email that never arrives. A small check proves both directions first, with a tokenised test message, a read-only inbox check, and broken config kept distinct from a broken server.

A storage server that answers a connection only proves a process is listening. I check each capability separately — browser uploads via presigned URL, private buckets refusing strangers, large files through the proxy — before any application depends on it.