The 20% Truth: AI’s Real Impact on Developer Productivity

Everyone says AI will 10x your dev team. But what does the data actually say?

In this episode of Fractional, Simon Obstbaum walks us through one of the most grounded conversations on developer productivity with AI you’ll hear.

Simon’s team at Stanford built a model trained on expert code reviews to study the actual impact of AI coding tools. What they found: a 20% productivity uplift at best—with wide variance depending on language, codebase complexity, and context.

We discuss:

• What productivity really means in software engineering

• Why legacy codebases often get worse with AI

• How LLMs quietly replace pair programming for junior devs

• What makes engineering teams more effective in reality—not theory

• Lessons from building Crunchyroll’s global tech org

This isn’t an AI hypefest. It’s a reality check.

https://www.swarm.work/podcasts/simon-obstbaum