diff.expert
Every large change is a sequence of small changes in disguise.
diff.expert teaches you diff decomposition — the skill of breaking large code changes into the maximum number of small, independently shippable increments.
Decomposition is the foundational skill for trunk-based development, continuous delivery, and effective AI-assisted engineering. Engineers who master it ship faster, review better, and collaborate more effectively — whether with humans or AI agents.
The same change. Two approaches.
One massive PR that no one wants to review, or a sequence of focused increments that ship daily.
1 PR · 1,159 lines changed
8 PRs · same destination
Why it matters
Every step ships
Each increment leaves the codebase working. Tests pass. You could stop anywhere and the system is better than before you started.
Faster reviews
Small, focused PRs get reviewed in minutes, not days. Reviewers stay engaged when each change has a single, clear purpose.
AI-ready
In the age of AI coding agents, your job is planning the sequence. Decomposition is the meta-skill that makes AI collaboration effective.
Ready to level up?
Learn the patterns, then practice until decomposition becomes instinct.
What's inside
Three tools for mastering decomposition.
Learn decomposition patterns with worked examples — from strangler fig to parallel change to feature flags.
Explore →Practice on real-world diffs with AI-scored feedback. Get a decomposition score and detailed commentary.
Explore →Quick-reference guide for choosing the right technique. Use it during planning sessions and code reviews.
Explore →