Security

AI writes about 41% of all committed code in 2026, and some teams report well above 50%. AI review tools have cut PR cycle times by as much as 59%. Yet when Sonar asked 1,149 developers for their 2026 State of Code report , 47% ranked “reviewing and validating AI-generated code for quality and security” the top skill in the AI era, above prompting at 42%. The paradox: the more code AI writes, the more vital human review becomes.

You can shrink your Linux server’s attack surface in about 30 minutes. The recipe is simple. Harden SSH with Ed25519 keys, set up nftables with default-deny, turn on auto security updates, run auditd for kernel logs, and lock down accounts with faillock. A typical Lynis score jumps from 55-62 on a stock install to 75-84 after these changes.

Each section below takes 3-7 minutes. Work through it top to bottom on a fresh server. You will have a solid security baseline before your first app deploys, whether that is a database or a privacy-respecting analytics instance .

AI test generators make it easy to hit 80% or even 90%+ line coverage. Point GitHub Copilot at a codebase, use the @Test directive, and watch it write hundreds of test methods by itself. The number looks great on a dashboard. But line coverage only measures execution, not detection. A test suite can run every line of your code while checking nothing about whether that code is correct. In one 2026 experiment, an AI-built suite scored 93.1% line coverage but only 58.6% on mutation testing. Over a third of realistic bugs slipped through undetected, with CI green across the board.

Bubblewrap (bwrap) is a small, unprivileged tool that sandboxes untrusted Linux apps and CLI tools with no root and no SUID binary. You build the sandbox mount by mount, so you control exactly what a program can see. It’s the same engine Flatpak runs inside. There is no daemon and no container image.

This guide is built around Bubblewrap: sandboxing desktop apps, locking down CLI tools and build scripts, network isolation, and runtime overhead. It also weighs bwrap against Firejail , the friendlier SUID-root sandbox with 1,000-plus ready-made profiles. That way you can see which one fits your threat model.

Caddy is the simplest reverse proxy for self-hosted services. It gets and renews TLS certificates from Let’s Encrypt with zero config. Install the static binary, write a Caddyfile with three lines per service, and Caddy handles HTTPS, HTTP/2, OCSP stapling, and renewal on its own. That replaces hundreds of lines of Nginx config and separate Certbot cron jobs.

If you run even a handful of services on a home server or VPS, a reverse proxy with proper TLS is non-negotiable. Caddy makes this painless, so there’s no excuse to skip it.

Yes, a plain Debian 12 or Fedora Server install on cheap x86 hardware, or a Raspberry Pi 5, makes a better router than most consumer gear. It often beats boxes that cost twice as much. You need two network interfaces, a few config files, and about two hours. The result is a gateway with a real stateful firewall via nftables , proper DNS and DHCP from dnsmasq , and traffic shaping that works through CAKE SQM. Every config is plain text you can track in Git.