Nico Voigt
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February 18, 2026

What I Learned by Failing to Build My Fitness App with AI Agents

Where AI coding agents shine, where they break, and the patterns that kept me shipping.

The promise vs. reality

  • Agents accelerate scaffolding
  • They struggle with long context
  • Reliability needs structure

Takeaways

  • Break work into vertical slices
  • Write contracts (types) first
  • Test early, test often
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