1582 articles
Network timeout on a payment request. Client retries. Customer gets charged twice. This is the most expensive bug in fintech — and it''s completely preventable with idempotency keys. Here''s the complete implementation.
Idempotent AI: idempotency keys for retries, Redis caching, replay on retry, avoiding duplicate tool calls, database upserts, and webhook deduplication.
You shard by user ID. 80% of writes go to 20% of shards because your top customers are assigned to the same shards. Or you shard by date and all writes go to the current month''s shard. Uneven distribution turns a scaling solution into a bottleneck.
Test Terraform modules with Terratest, enforce policies with OPA/Conftest, scan with tfsec, and catch infrastructure bugs in CI before deployment.
Prevent algorithm confusion attacks, implement safe key rotation, detect token theft with refresh token families, and secure JWTs with binding and revocation strategies.