Notes on backend engineering, Python, TypeScript and LLM/RAG in production.https://mdislam.dev/enhttps://mdislam.dev/blog/2026-11-04-circuit-breakers-failing-fast/https://mdislam.dev/blog/2026-11-04-circuit-breakers-failing-fast/When a downstream service is struggling, waiting on it makes things worse. A circuit breaker stops calling it for a while so both sides can recover.Wed, 04 Nov 2026 00:00:00 GMTbackendreliabilityarchitecturehttps://mdislam.dev/blog/2026-11-03-retries-exponential-backoff-jitter/https://mdislam.dev/blog/2026-11-03-retries-exponential-backoff-jitter/A retry loop can rescue a request or take down a struggling service. Here is how to retry with backoff, jitter and a budget so it does the first.Tue, 03 Nov 2026 00:00:00 GMTapi-designbackendreliabilityhttps://mdislam.dev/blog/2026-11-02-zero-downtime-schema-migrations/https://mdislam.dev/blog/2026-11-02-zero-downtime-schema-migrations/Old and new code run side by side during every deploy. Here is how to change a database schema in small, safe steps so neither version breaks.Mon, 02 Nov 2026 00:00:00 GMTdatabasesbackendpostgresdevopshttps://mdislam.dev/blog/2026-10-31-graceful-shutdown-sigterm/https://mdislam.dev/blog/2026-10-31-graceful-shutdown-sigterm/Every deploy stops your old processes. Here is how to handle SIGTERM so in-flight requests finish, connections close cleanly and users never notice.Sat, 31 Oct 2026 00:00:00 GMTbackenddevopsreliabilitydockerhttps://mdislam.dev/blog/2026-10-30-structured-logging-json/https://mdislam.dev/blog/2026-10-30-structured-logging-json/Plain text logs are easy to write and hard to search. Here is how structured logs with consistent fields make debugging production services faster.Fri, 30 Oct 2026 00:00:00 GMTbackendobservabilitypythondevopshttps://mdislam.dev/blog/2026-10-29-liveness-readiness-health-checks/https://mdislam.dev/blog/2026-10-29-liveness-readiness-health-checks/What liveness and readiness checks are for, why mixing them up causes restart loops, and how to write health endpoints that tell your platform the truth.Thu, 29 Oct 2026 00:00:00 GMTdevopskubernetesbackendreliabilityhttps://mdislam.dev/blog/2026-10-28-database-connection-pooling/https://mdislam.dev/blog/2026-10-28-database-connection-pooling/Why opening a database connection per request hurts, how a connection pool fixes it, and how to choose pool sizes that do not overload your database.Wed, 28 Oct 2026 00:00:00 GMTdatabasesbackendpostgresperformancehttps://mdislam.dev/blog/2026-10-27-rate-limiting-token-bucket/https://mdislam.dev/blog/2026-10-27-rate-limiting-token-bucket/How the token bucket works, why it handles bursts better than a fixed window, and what to think about when you run it across several servers.Tue, 27 Oct 2026 00:00:00 GMTapi-designbackendredisarchitecturehttps://mdislam.dev/blog/2026-10-26-docker-multi-stage-builds/https://mdislam.dev/blog/2026-10-26-docker-multi-stage-builds/How multi-stage Dockerfiles keep compilers and dev dependencies out of your final image, with a simple Node example and a few habits that help.Mon, 26 Oct 2026 00:00:00 GMTdockerdevopscontainershttps://mdislam.dev/blog/2026-10-25-http-caching-etags/https://mdislam.dev/blog/2026-10-25-http-caching-etags/How browsers and proxies decide when to reuse a response, and how Cache-Control and ETags let your API skip work it has already done.Sun, 25 Oct 2026 00:00:00 GMThttpperformancebackendhttps://mdislam.dev/blog/2026-10-24-access-and-refresh-tokens/https://mdislam.dev/blog/2026-10-24-access-and-refresh-tokens/A short-lived access token plus a longer-lived refresh token is a common login pattern. Here is what each one does and how to handle them safely.Sat, 24 Oct 2026 00:00:00 GMTsecurityauthenticationbackendhttps://mdislam.dev/blog/2026-10-23-database-indexes-explained/https://mdislam.dev/blog/2026-10-23-database-indexes-explained/Indexes fix slow queries but can slow down writes. What they actually do, and how to decide when one is worth it.Fri, 23 Oct 2026 00:00:00 GMTdatabasesbackendperformancehttps://mdislam.dev/blog/2026-10-23-idempotent-apis-safe-retries/https://mdislam.dev/blog/2026-10-23-idempotent-apis-safe-retries/Networks fail in awkward ways. Designing endpoints so that a repeated request does no extra harm is one of the cheapest reliability wins you can get.Fri, 23 Oct 2026 00:00:00 GMTapi-designbackendreliabilityhttps://mdislam.dev/blog/2026-10-23-why-i-write-every-day/https://mdislam.dev/blog/2026-10-23-why-i-write-every-day/A daily engineering log: what I learn building backend and LLM features in production, written down while it's still fresh.Fri, 23 Oct 2026 00:00:00 GMTwritingcareerhttps://mdislam.dev/blog/2026-10-23-ai-future-of-industry/https://mdislam.dev/blog/2026-10-23-ai-future-of-industry/Where AI is already useful in manufacturing, healthcare, software, logistics and energy, how work is changing, and what responsible use looks like.Fri, 23 Oct 2026 00:00:00 GMTaiindustryfuturehttps://mdislam.dev/blog/2026-10-22-fastapi-settings-pydantic/https://mdislam.dev/blog/2026-10-22-fastapi-settings-pydantic/Load and validate environment variables once, fail fast on bad config, and keep secrets out of your code: a small pattern I use in every FastAPI service.Thu, 22 Oct 2026 00:00:00 GMTpythonfastapibackend