Our Buildkite Brings All the Devs to the Yard: (Re)Building Reddit Mobile CI in 2025
Article Summary
Reddit's mobile team had zero professional CI experience. Then they cut build times in half and transformed developer happiness.
Geoff Hackett shares how Reddit's Mobile Platform team evaluated 10 CI providers, built prototypes for their top picks, and ultimately migrated 200+ mobile developers to Buildkite. The journey took over a year from evaluation to production.
Key Takeaways
- Build times improved 33% at p50 and 47% at p90
- Merge queue times dropped from 30 minutes to 15 minutes
- Concurrency usage cut in half despite faster builds
- Git checkout reduced from 4 minutes to 30 seconds with caching
- Dynamic pipeline generation in Python beat hardcoded YAML approaches
Critical Insight
Reddit migrated their entire mobile CI to Buildkite, achieving 50% faster builds while using less compute and dramatically improving developer sentiment.
