Notes that connect implementation to engineering judgment.
Implementation-backed articles and concise design notes on delivery guarantees, failure recovery, capacity, and the evidence still needed to validate each claim.
4 min read
Backend reliability · Worker correctness
Commit before ack: accepting the duplicate window
Why persistence precedes acknowledgement, which effects a unique key protects, and how real helper-process exits verify the two commit boundaries.
Transactional outbox recovery: close the acceptance gap
The implemented transaction and dispatcher contract for durable acceptance, confirmed publication, and duplicate-safe recovery after a real subprocess exit.
Backpressure under load: bound work before measuring scale
How admission, prefetch, database capacity, and retries interact, with corrected measurements of submission through observed committed results on a local host.
Deterministic checkpoint recovery: what state must survive?
A code-backed examination of atomic checkpoints, configuration identity, RNG restoration, and the exact-equality test that separates a real restart from a plausible-looking continuation.
Why at-least-once delivery requires an idempotency strategy
A concrete worker contract for stable message identity, durable acceptance, duplicate suppression, bounded retries, and dead-letter handling—grounded in executable Go tests.