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Agent engineering.

Subagents, skills, MCP servers, RAG — the building blocks of agents that do real work, each explained with something you can build.

Agent engineering · 1. Sep 2026

Swap the LLM, keep the code: one RAG app on Azure, OpenAI and local Mistral

The application code never changed when I swapped the LLM three times. The configuration nearly beat me — and the two traps are worth knowing.

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Agent engineering · 25. Aug 2026

RAG explained by building it: the smallest working app with Spring AI

You don't need LangChain or a vector database to understand RAG. The whole loop fits in two Java classes — and building it that small is the point.

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Agent engineering · 24. Aug 2026

Automate invoicing with MCP: my Invoice Ninja server

“Log 45 minutes of weekly meeting on the Audioempire project, cost 0.” One sentence, done. Behind it sits an MCP server I run myself — and one day where it deleted tracked hours.

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Agent engineering · 17. Aug 2026

Claude Code Subagents vs. Skills: The Practical Guide

An agent that does everything does nothing well. Subagents and skills are the difference between a toy and a tool — here you build both, from a real example, and learn when each abstraction is the right one.

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Agent engineering · 10. Aug 2026

MCP Enterprise Adoption: Outgrowing the Tinkering Phase

97 million SDK downloads, enterprise auth in the standard — MCP has outgrown the laptop. What that means for teams moving from prototype to production, and the five questions to answer before the first production server.

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Agent engineering · 3. Aug 2026

1M Token Context: Feed Your Agent Like an Architect

Sonnet 5 reads a million tokens. Most people still feed their agent one file at a time — and give away the actual leap. What big context changes in practice, where it hurts, and a rule of thumb for daily work.

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Agent engineering · 22. Jun 2026

Write your first MCP server in 30 minutes

An MCP server isn't magic: a handful of functions, cleanly described. Here you build your first one and plug it into your coding agent.

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AI code without tech debt — the checklist

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