Why Did systemd OOM-Kill My Service (and How to Stop It)
Your service vanished with no crash log because the kernel OOM killer took it. Confirm it from journalctl and dmesg, read the real memory pressure, then bound it with cgroup limits.
Delivery & Build
sysctl Tuning That Earns Its Keep: Network and Kernel Settings for a Busy Server
Most sysctl optimisation lists are cargo cult. Here is a defensible /etc/sysctl.d drop-in for a busy Linux server, with why each setting exists and how to confirm it took effect.
VoP Response Codes and the Customer Journey: Match, Close-Match, No-Match in Your UI
Verification of Payee returns graded results, and the product decisions around close-match and no-match are where fraud loss and customer abandonment collide. How to design the response handling deliberately.
Why Did Git Detach My HEAD (and How to Get Back on a Branch Without Losing Work)
What a detached HEAD actually is, the operations that trigger it, and how to recover commits made while detached using a branch and the reflog.
Argument Parsing in Bash: getopts, Long Options and a –help That Works
Hand-rolled $1/$2 argument handling breaks the moment flags get reordered. Here is a copy-pasteable getopts block with long options, validation and a working –help.
Why Did My Celery Task Execute Twice? Visibility Timeout, acks_late and Idempotent Tasks
A Celery task that sent two emails traces back to how brokers redeliver messages. Here is the root cause and the real fix: make the task idempotent.
Replacing black, flake8, and isort With a Single Tool: Migrating to Ruff
How to retire black, flake8, isort and their plugins in favour of one Rust-based tool: port your rules into ruff.toml, enable the formatter, and enforce it in CI.
Reliable Webhook Delivery: Retries, Exponential Backoff, Dead-Letter and Idempotent Receivers
Reliable webhook delivery is a queue problem: retry with exponential backoff, dead-letter what will not send, and dedupe on event ID so retries are safe.
Per-Project Environments With direnv: Auto-Loading Secrets and PATH on cd
Install direnv, hook it into your shell, and write .envrc files that activate a virtualenv, export project-scoped variables and extend PATH — all revoked automatically when you leave the directory.
pg_dump and pg_restore: The Flags That Actually Matter
The pg_dump and pg_restore invocations worth memorising on PostgreSQL 17: directory vs custom format, parallel –jobs, scoped dumps, portable restores and the foreign-key section trap.