Notes on systems, security, building products, and everything in between.https://alvaroblanco.dev/enhttps://alvaroblanco.dev/en/blog/two-claude-code-accounts-in-parallel/https://alvaroblanco.dev/en/blog/two-claude-code-accounts-in-parallel/Got a personal account and a work one in Claude Code? With CLAUDE_CONFIG_DIR and direnv you can keep both active at once without ever logging out. A 3-minute setup.Sat, 27 Jun 2026 00:00:00 GMThttps://alvaroblanco.dev/en/blog/spec-driven-development/https://alvaroblanco.dev/en/blog/spec-driven-development/Prompt Driven Development is broken. Most devs ask AI for technical things and then act surprised when the result doesn't fit. SDD flips the equation: you define the behavior, AI implements.Sun, 24 May 2026 00:00:00 GMThttps://alvaroblanco.dev/en/blog/i-bought-a-nas-digital-sovereignty-backups/https://alvaroblanco.dev/en/blog/i-bought-a-nas-digital-sovereignty-backups/Why I decided to buy a NAS: stop depending on the cloud, take back control of my data, real backups for three devices, RAID1 with IronWolf and Backblaze B2 as an offsite layer.Fri, 01 May 2026 00:00:00 GMThttps://alvaroblanco.dev/en/blog/the-vercel-hack-supply-chain-oauth/https://alvaroblanco.dev/en/blog/the-vercel-hack-supply-chain-oauth/An employee connected an AI tool to their corporate account. Months later, that connection was the entry vector. This is not a Vercel problem. It is everyone's problem.Wed, 22 Apr 2026 00:00:00 GMThttps://alvaroblanco.dev/en/blog/how-i-automated-my-finances-with-notion-and-ai/https://alvaroblanco.dev/en/blog/how-i-automated-my-finances-with-notion-and-ai/How I built an automated financial management system with Notion, Python and Google Gemini to classify thousands of bank transactions without manual effort.Sun, 07 Dec 2025 00:00:00 GMThttps://alvaroblanco.dev/en/blog/from-geopolitics-to-your-smartphone-ad/https://alvaroblanco.dev/en/blog/from-geopolitics-to-your-smartphone-ad/OPSEC (Operational Security): what it is, where it comes from and why operational security is as relevant today as it was during the Vietnam War.Thu, 09 Oct 2025 00:00:00 GMThttps://alvaroblanco.dev/en/blog/c2-command-and-control/https://alvaroblanco.dev/en/blog/c2-command-and-control/A complete introduction to Command & Control: what it is, how agents communicate, its main components and its use in red teaming.Tue, 26 Aug 2025 00:00:00 GMThttps://alvaroblanco.dev/en/blog/goodgames-writeup/https://alvaroblanco.dev/en/blog/goodgames-writeup/Writeup of HackTheBox's GoodGames machine: SQL Injection, SSTI in Jinja2, Docker escape and privilege escalation.Mon, 04 Aug 2025 00:00:00 GMThttps://alvaroblanco.dev/en/blog/building-a-homelab-server-part-1/https://alvaroblanco.dev/en/blog/building-a-homelab-server-part-1/How I built my own homelab from scratch: motivations, components, choosing the operating system and the mistakes you should not make.Tue, 18 Feb 2025 00:00:00 GMT