The difference between junior and senior developers isn't just experience—it’s how they think. Senior devs use mental models like the Feynman Technique, Fermi Estimation, and First-Principles Thinking to break down problems and find efficient solutions.
The Feynman Technique: Debugging via Storytelling
Concept: If you can’t explain it simply, you don’t understand it well enough.
Application: Explain your code to an imaginary junior dev to identify gaps in logic.
Fermi Estimation: Quick, Rough Calculations
Concept: Make rapid, educated guesses to prioritize effort.
Application: Estimate performance bottlenecks before diving into deep profiling.
First-Principles Thinking: Rebuild from Scratch
Concept: Strip away assumptions and solve from the ground up.
Application: Instead of blindly optimizing, rethink algorithms and structures.
By mastering these models, you’ll debug smarter, design systems more effectively, and write better code.
🚀 Want the full breakdown with real-world case studies? Read the complete guide on my blog at Developer Talks.
