This workflow checks input before hashing it and routes failures to an error output. Validate presence, type, and size first; only valid input should reach the hash step. Treat a bad input differently from a temporary dependency failure and from an unexpected internal error.
Use a structured error with a code, safe message, and correlation ID. Retry only operations known to be safe to repeat, with a bounded attempt count. Keep sensitive input and stack traces out of user-visible responses, while retaining enough private diagnostics to investigate. Test empty input, an oversized value, and a simulated downstream outage so each branch has a clear outcome.
Akousa