docker
Shrink a Rails Docker image from 1 GB to under 150 MB in seven ordered steps: smaller base image, .dockerignore, multi-stage builds, layer ordering, distroless with its honest caveat, and digest pinning. Every step is measurable the same afternoon.
fail2ban
Fail2ban turns brute-force noise on SSH and your reverse proxy into a boring automated reaction. A practical setup for a VPS or homelab: sane jail config, testing before trusting, notifications without a siren, and where it fits in the wider security story.
dora
DORA metrics explained for engineering leaders: deployment frequency, lead time, change failure rate, time to restore and reliability. What each one really tells you, how to use them to improve delivery, and the anti-patterns that turn them into dashboard theater.
Architecture is the set of decisions that feel permanent after six months. An honest tour of monolith, layered, modular monolith, SOA, microservices and event-driven options: what each really costs and why the modular monolith deserves more attention than it gets.
Microservices promise independence and deliver network calls where method calls used to be. Why small and medium teams pay the highest price: chaos scaling instead of product scaling, lost shared context, operational overhead, and the way back to sanity.
PostgreSQL database size checks in a few simple SQL queries: list all databases with pg_database and pg_size_pretty, then break down the biggest tables in a schema, indexes included. Spot what eats disk space before it slows backups and raises infrastructure costs.
Idle PostgreSQL connections eat memory and can hit the max_connections limit, blocking your app. How to find old sessions in pg_stat_activity, close them safely with pg_terminate_backend, and automate the cleanup so hanging connections never pile up again.
Ruby can replace Bash for system scripts that outgrow a few lines: real error handling, readable syntax, easy testing. Examples of bulk folder compression, process management, file operations, making scripts executable, and when Bash is still the better pick.
Dockerize NextJS development with docker-compose watch: sync ./src into the container, rebuild on dependency changes, and keep hot reload working. A complete docker-compose.yml and Dockerfile you can copy for a reproducible dev environment in minutes.
Locked out of SSH? Portainer can get you root back: deploy a privileged busybox container that mounts the host filesystem at /host and gives you an interactive shell. The exact Docker Compose script, the security implications, and when this trick is justified.
Run any command in the background in bash by appending &, check it with jobs, and stop it with kill -9 %. A short guide using a Rails server as the example, so long-running processes stop blocking your terminal while you keep working.