Alexander Opalic's Claude Code Deep Dives
Table of content

Alexander Opalic is a senior full stack developer based in Germany, currently working at Otto Payments on Vue.js and Node.js applications. He studied Media Informatics at LMU Munich and has spent 6+ years building with modern JavaScript frameworks. His technical blog at alexop.dev has become the go-to resource for understanding Claude Code’s architecture.
Opalic runs alexop.dev, a blog that has become essential reading for Claude Code users. His posts explain the tool’s layered architecture in the order features were introduced — from MCP servers to plugins to agent skills.
The Full Stack Explainer
Opalic’s Understanding Claude Code’s Full Stack is the definitive guide to how Claude Code’s features connect:
| Layer | Introduced | Purpose |
|---|---|---|
| MCP Servers | Nov 2024 | External tool connections |
| Claude Code Core | Feb 2025 | Agentic coding foundation |
| Plugins | Oct 2025 | Shareable configurations |
| Agent Skills | Oct 2025 | Auto-discovered capabilities |
His key insight: most users try one or two features without understanding how they stack together.
Key Blog Posts
CLAUDE.md, Skills, Subagents Explained
Covers the customization hierarchy:
- CLAUDE.md — Always-loaded project context
- Slash commands — Prompts invoked with
/command - Subagents — Specialists with their own context window
- Skills — Rich, auto-discovered capabilities
Critical insight: Subagents keep your main context clean. In plan mode, Claude Code delegates repo scanning to an Explore-style subagent so your main thread doesn’t balloon.
Building an AI QA Engineer
Practical guide to combining Claude Code with Playwright MCP for automated testing:
# GitHub Action that runs Claude as a QA engineer
- Tests your app through the browser like a real user
- Posts bug reports with screenshots to PRs
- Named "Quinn" with a defined personality
What Is MCP and How It Works
Opalic’s MCP awakening came from the Playwright integration:
“I asked Claude to audit my site for SEO. It ran checks in a real browser, gave me the results, and sent screenshots. This was not just text prediction. This was an AI that can see and work with the web like a human tester.”
Building My First Claude Code Plugin
Step-by-step guide to creating plugins — shareable bundles of commands, hooks, skills, and subagent definitions.
Bold Predictions
In In Five Years, Developers Won’t Write Code By Hand, Opalic makes strong claims:
“I haven’t written code by hand in months. This year alone, I built four complete projects using only Claude Code.”
Projects built entirely via prompts:
- A markdown editor
- A Nuxt blog starter
- A workout tracking app
- His “Second Brain” personal site
Working Method
Opalic’s approach from his various posts:
- Use Claude Code for everything — Not just coding, but testing, deployment, documentation
- Build on MCP — External connections multiply Claude’s capabilities
- Create plugins for your stack — He envisions Vue/Nuxt plugins that teach Claude those frameworks
- Share what you learn — His blog exists partly to solidify his own understanding
Background
From his about page:
“I’m a developer from Germany passionate about technology and knowledge sharing.”
His content types:
- Blog posts — Well-researched, carefully crafted
- TILs — Quick learning moments
- Notes — Help internalize new concepts
Technical Focus
Based on his posts, GitHub, and LinkedIn activity, Opalic works primarily with:
- Vue.js and Nuxt
- TypeScript
- Claude Code + MCP ecosystem
- GitHub Actions for automation
Key Takeaways
| Principle | Application |
|---|---|
| Learn features in order | MCP → Core → Plugins → Skills |
| Subagents preserve context | Delegate exploration tasks |
| MCP unlocks real-world actions | Browser, databases, APIs |
| Plugins make config shareable | One install, full workflow |
Links
- alexop.dev
- GitHub: alexanderop
- X/Twitter
- Understanding Claude Code’s Full Stack
- Claude Code Customization Guide
- Building an AI QA Engineer
- Slash Commands Guide
Next: Thorsten Ball’s Agentic Coding Vision
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