Farfetch's Mobile App Launch Performance II
Original post Mobile App Launch Performance II
Article Summary
At Farfetch, a 0.1 second delay in warm app launch costs $4.2M annually. That's less time than it takes to blink.
The Farfetch mobile team breaks down the business case for app launch performance, translating milliseconds into dollars. With 1 million+ daily launches across their iOS app, they've quantified exactly how much every second of delay costs in conversion rates and customer relationships.
Key Takeaways
- Every 1 second delay in app launch reduces conversion rate by 7%
- Farfetch saves 12 days of cumulative launch time per 1 second improvement
- Cold launch exceeding 2 seconds creates $350K opportunity cost for new users
- Performance budgets enable trade-off discussions between engineering and product teams
- MetricKit and Instruments provide development-time performance measurement on iOS
Measuring app launch performance and setting budgets transforms performance from an afterthought into quantifiable business decisions that engineering and product teams can negotiate together.
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What This Article Covers
Farfetch's iOS app launches over 1 million times daily and gets 100,000 new downloads per release. App launch is the first experience users have, so it matters most.
The team set TTI baselines at 2 seconds for cold launch and 1.5 seconds for warm launch. They created performance budgets by adding up inner stage budgets to get their targets.
Research shows 19% of customers uninstall apps that take over 5 seconds to load. Performance budgets give teams a common language for making trade-off decisions.
This page summarizes “Mobile App Launch Performance II” by Farfetch, published Nov 3, 2020. All credit for the original work goes to the authors.
