certbot had been running quietly on my server for almost two years without a single issue. Automatic renewals. Silent cron job. I never thought about it. Set it up once, tested it once, and mentally moved it to the "solved" column of my infrastructu...

Three Lines of Bash Stand Between Your Cron Job and a Silent Outage Level: Intermediate · Time: 6 min · Outcome: A hardened, ShellCheck-clean cron wrapper generated for you Three separate incidents taught me the same lesson over about a year. A /1...

A demo script called report, two directories on PATH, and one mv between them, all on a scratch tmpfs: $ report report 2.1: 14 jobs ok exit=0 $ mv /opt/jobs/bin/report /opt/jobs/newbin/report $ ls -l /opt/jobs/newbin/report rwxrwxr-x 1 root root 42 ...

A 64M scratch tmpfs, a worker process holding its log open on file descriptor 3, and the usual reflex when space runs low: rm the log. du on the directory dropped from 48M to 0. df stayed at 48M used. The next 32M write failed with No space left on d...

The standard bash alerting pattern ends the same way everywhere you read it: pipe the finding into mail. So I checked what my own box would actually do with that line. $ type -a mail mailx sendmail mail not found mailx not found sendmail not found ...

Who owns that port? One ss flag answers it without sudo For months my dev server started on 3001 because something already held 3000, and I kept stepping around it. When I finally asked, ss -ltn 'sport = :3000' showed the port listening on every in...

A script that writes straight to the path a consumer reads can die halfway and leave a torn file that everything downstream loads as complete. No error appears anywhere, because the only process that failed is gone. I tested the fix the unfriendly wa...

A four-line YAML file port: 8080, supportemail, transport: tcp, reportdir: /var/reports and the rename most people type first: sed -i 's/port/listenport/g' app.yml. GNU sed 4.9 exited 0 and printed nothing, because -i never does. Afterwards the file ...

I set three log files to known ages with touch -d — exactly 30 days, 30 days and 12 hours, and 31 days — then ran what I thought was a 30-day retention policy: find . -name '.log' -mtime +30 It returned one file: the 31-day-old one. The 30.5-day f...

I meant to delete the .cache files under a data directory. The server had been running for two months and the cache layer had grown to about 14GB. The application team told me it was safe to purge it — they'd rebuilt the cache logic and the old files...

My Backup Hadn't Run in 9 Days and Nothing Told Me Level: Intermediate · Time: 5 min · Outcome: A cron command that can't hang forever The backup ran fine every night for fourteen months, and then it didn't run for nine days, and nothing told me. ...

Nobody announces small features. You ship them, they're in there, and the people who find them either notice or they don't. I want to start documenting these because some of them are the kind of thing that makes a tool actually worth using day-to-day...

Here's a script that will ruin your day: !/bin/bash cd /nonexistent/folder rm -rf echo "Done" The cd fails because the folder doesn't exist. Bash ignores the failure. rm -rf runs in whatever directory you were already in. The script prints "Done...

The Problem Nobody Talks About 970 million people worldwide live with mental health disorders. But almost every mental health tool built with AI assumes the same user: fast internet, English as a first language, a US or UK phone number to call in ...

I'm Wasey, a solo developer from Varanasi, India. I built DramaHub — a fully live OTT streaming app on Google Play Store. 7,000+ downloads, 1,000+ daily active users, sub-1% crash rate, ₹0/month infrastructure. Here's the exact architecture that m...

I have lost work exactly once. It was a side project. A static site I'd been building over a weekend. I was reorganizing the folder structure, running mv commands to shuffle things around, and I fat-fingered a path. Moved an entire directory into a ...

Most developers buy a domain before deploying a portfolio or project online. But recently, I discovered DigitalPlat FreeDomain — a platform that allows developers to register free domains under extensions like .qzz.io and connect them to services l...

I Google "bash remove file extension" at least once a month. Every time I need ${filename%.txt} I have to look it up. I've written that exact syntax probably 40 times across different scripts. My brain refuses to memorize it. And every time I need i...