We Need to Talk About Migrations With AI: Asana, Airbnb, Uber, and Bun All Make 'Impractical' Migrations Doable
Summary
Compares AI-assisted migration case studies (Asana's Enzyme removal in 2 weeks for $12K vs. an estimated $6M/5-years by hand; Airbnb's 3,500-test migration in 6 weeks; Uber's 600K-test JUnit migration in 4 months; Bun's 530K-line Rust rewrite) and argues AI is unlocking a wave of previously-shelved migrations, while stressing engineers still must plan, design verification loops, and stay involved throughout.
Why this signal
Gives Neo multiple concrete, comparable ROI data points beyond the Bun case already known — directly useful for making the case internally that specific stalled Thomas Engineering migrations may now be tractable, with realistic guardrails (plan + verification loops, not full automation).
Original email
The Pragmatic Engineer · 8/20/2026
The Pulse: We need to talk about migrations with AI