#S3

A stateless Rust service that renders the first page of a PDF into a sharp, uniformly sized WebP thumbnail, reading the PDF and writing the image through two presigned links, so no application streams files or holds storage credentials.

A small Rust service between applications and S3-compatible storage: it hands out presigned links so browsers talk to storage directly, gives each file a lifecycle, copies between buckets on the server, and keeps storage credentials out of every application.

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.

A 4 GB GPU pushed the heavy work onto a borrowed Colab runtime, so a laptop and that runtime had to share one store. Storing the data was easy. Believing it was not: seven of the ten obstacles were successes that were false, and the most useful fix removed an entire layer.

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.