Hands-on notes on Java, Rust, Cloudflare, Docker and more. Every post is something that broke, why it broke, and how it got fixed.
Your CPU can sit idle while your bandwidth is full, and a handful of expensive requests can stall an app that looks fine. This guide walks through where DDoS attacks hit, how to tell them apart from traffic spikes and bad deploys, and which defenses cover which layer.
Security · · 17 min read
Cloudflare 11 min read
Cloudflare Error 521 (Web server is down) isn't fixed by clearing the cache — it means your origin refused Cloudflare's connection. This guide walks the path from web service and listening ports through firewalls / WAF and SSL/TLS ports to load balancers, plus a ready-to-send support ticket template.
DNS 11 min read
Pages may already use HTTPS, but DNS lookups are often still sent in the clear. DoH encrypts the first hop to your resolver. It is not anonymity, and it does not replace DNSSEC.
Nestjs 8 min read
Use Express for small services, prototypes, and webhooks. Use NestJS for a business backend a team will keep maintaining. Nest still runs on Express by default. Switch to Fastify only if a load test shows the HTTP layer is the bottleneck.
Nestjs 18 min read
Start a NestJS project, then use Controller, Service, Module, and DTO to build a testable task API and see how a request is handled.
Nextjs 17 min read
NestJS handles complex backends. Next.js handles React pages and SEO. The names look alike; the layers do not. Compare positioning, architecture, routing, realtime, performance, testing, and how to choose in 2026.
Cloudflare 16 min read
I recently connected a third-party app to Cloudflare's OAuth Client. These are my notes from creating the client through a working authorization-code flow.
