SSL/TLS

Every time you load an HTTPS page, a TLS handshake happens in milliseconds. Most people treat it as a black box — it works or it doesn’t. But understanding what actually happens is useful when you’re debugging TLS errors, optimizing performance, or configuring cipher suites. The Purpose of the Handshake The handshake does three things: […]

I used cron for years without really questioning it. It works, it’s everywhere, it’s well-understood. But over time I noticed a few recurring frustrations: no built-in logging, missed jobs when the system was off, no dependency management, and debugging failed jobs meant hunting through syslog. Systemd timers solve most of these problems, and on systems

Disk space has a way of filling up at the worst possible time. I’ve had databases refuse to write because /var was full, deployments fail because /tmp was full, and applications crash because their log directories hit quota. All of them were preventable with basic disk space management. Here’s how I handle it. Finding Large

I spent years using OpenVPN for internal VPNs and I was always mildly frustrated by it. The configuration files are long, the certificates require careful management, the performance is decent but not great, and debugging connection issues is painful. Then I tried WireGuard and everything got simpler. WireGuard is modern, fast, and has a remarkably

PHP-FPM (FastCGI Process Manager) is how PHP runs behind Nginx. The two don’t talk to each other directly — Nginx hands PHP requests to PHP-FPM via FastCGI, PHP-FPM processes them, and sends responses back. Getting this configuration right affects both performance and stability. I’ve set this up dozens of times. Here’s what I’ve learned about

UFW (Uncomplicated Firewall) is the default firewall management tool on Ubuntu. It’s a frontend to iptables that makes common firewall tasks manageable without having to write iptables rules directly. I use it on most of my Ubuntu servers — it handles the 95% case well and doesn’t get in the way. Installation and Initial State

If you’ve ever tried to install an SSL certificate and hit a wall because the server expects .crt but your CA sent you .pem, you know how frustrating this rabbit hole can get. I’ve been there more times than I’d like to admit. The good news is that once you understand what these formats actually

Redis is one of those services that starts as a simple cache and ends up being a critical piece of infrastructure. I’ve used it for session storage, rate limiting, job queues, pub/sub, and as a general-purpose key-value store. Getting the configuration right from the start saves headaches later. Installation For the latest stable version from

Both wildcard and SAN (Subject Alternative Name) certificates solve the same core problem — securing multiple domains or subdomains with one certificate. But they work differently and have different costs, limitations, and use cases. Picking the wrong type leads to either unnecessary expense or coverage gaps. What Wildcard Certificates Cover A wildcard certificate secures *.example.com