App Size Matters II
Article Summary
What if I told you a single 15MB increase in your app size could cost your business $1M annually? Farfetch's mobile team did the math, and the numbers are eye-opening.
The Farfetch engineering team tackled a question most companies ignore: what's the actual business cost of app bloat? With 60+ mobile developers shipping features every two weeks, they needed a framework to make performance discussions as concrete as feature roadmaps.
Key Takeaways
- Each megabyte costs 450 iOS app installations (apps under 100MB)
- A 15MB increase equals $350K opportunity cost per release at Farfetch
- Performance budgets now block releases that exceed app size thresholds
- Teams negotiate SDK additions using quantified megabyte budgets per quarter
By monetizing app size at $50-150 GTV per lost download, Farfetch turned performance into a first-class product decision with hard numbers that engineering and business both understand.
About This Article
Farfetch needed to make app performance discussions as easy to prioritize as business initiatives. Business features are simpler to evaluate because they come with clear revenue projections.
The team worked with Product Analytics to track user behavior through download funnels. They found that apps over 100MB lose 0.45% of iOS installs for every additional megabyte, based on Segment data.
Performance budgets became mandatory checkpoints before any release could ship. Teams now review them quarterly to decide which SDKs to add and whether existing modules should be replaced.
