Practical technology knowledge
Tutorials, guides, comparisons and analysis on security, Linux, networking, development, cloud and the tooling that powers modern technology — written by practitioners, for practitioners.
Free tools
Most run entirely in your browser, so nothing you paste — a token, a password, production data — is ever sent to us.
CEH gets a CV past a filter. OSCP convinces the person running the technical interview. Which one is worth six months of your evenings depends entirely on which gate is actually in front of you.
CloudFront meters delivery and gives you free origin egress from AWS. Cloudflare does not meter delivery but your S3 bucket still bills you on every cache miss. Which one wins comes down to a number most people have never measured.
Middleware is not an authorisation boundary — CVE-2025-29927 proved it with one header. Where to put the check so a page, a route handler and a Server Action are all covered, what leaks into the RSC payload, and the CSP choice that costs you static rendering.
printk is the tool most likely to hide the bug you are chasing. Dynamic debug switches instrumentation on per line at runtime with no rebuild, ftrace shows what actually ran, and faddr2line turns an oops into a source line.
The directives are the easy part. Behind a CDN, the usual configuration rate-limits the proxy and throttles every visitor as one. Here is the leaky bucket explained, burst and delay tuned properly, and real_ip set up safely.
A default docker run gives you root, a writable filesystem, most capabilities and no resource ceiling. Here is every hardening flag worth applying — with the four that block host compromise separated from the sixteen that are ordinary hardening.
Wi-Fi 7's headline 46 Gbps is unreachable and beside the point. Multi-Link Operation is the real upgrade, 320 MHz channels are regionally constrained, and Wi-Fi 8 certification is a 2028 matter.
A local hook is bypassed by --no-verify, lives outside the clone, and never sees a web commit. Set it up anyway, then put the real enforcement in CI and push protection — and rotate before you rewrite history.
A working reverse proxy config is the easy part. Lost client addresses, buffered streaming, silent WebSocket failures and security headers that vanish on error pages are what actually cost you an afternoon.
Record your cleanup once and replay it with a click. The transformations that matter, combining a whole folder of files, query folding and why refreshes get slow, and the automatic step you should always delete.
