San Francisco – August 4, 2025 – Buildkite Pty Ltd, a leader in scalable software delivery solutions, today announced that Reddit, one of the world’s largest online communities with more than over 400M weekly active users, has successfully migrated its mobile continuous integration and delivery (CI/CD) pipelines to Buildkite, dramatically improving build performance, reliability, and developer autonomy across its mobile engineering organization. By adopting Buildkite’s high-performance hosted agents and dynamic pipeline primitives, Reddit has reduced build queue times to just seconds and accelerated build speeds by 30% for both Android and iOS workflows, while maintaining cost efficiency.
“With Buildkite, we finally have the reliability and performance at scale that our mobile teams were missing,” said Ken Struys, Reddit’s Director of Developer Experience. “We’ve seen a significant improvement to the overall developer experience, and both Android and iOS CI are more than 30% faster on Buildkite.”
Facing growing demands from millions of global users and a rapidly expanding codebase, Reddit’s mobile teams had outgrown their previous CI/CD provider. Lack of ability to control the build environment meant they couldn’t use custom Docker images (as they can with Buildkite). The team also struggled with configuration complexity, with 6,000 lines of YAML split across multiple files, in addition to unreliable builds due to environment drift and dependency failures.
Reddit’s migration to Buildkite, affecting over 200 mobile engineers, was completed ahead of schedule and involved a full transition of both Android and iOS mono repositories. The company leveraged Buildkite’s composable pipeline primitives to create custom workflows that seamlessly integrated with Bazel and BuildBuddy, allowing both iOS and Android apps to be built efficiently on Linux runners with remote execution. Dynamic pipelines enabled Reddit to build powerful CI systems with less cruft and less code repetition.
Comprehensive benchmarking revealed that Reddit’s builds now run up to 30% faster, with job queue times consistently dropping to around five seconds. Buildkite’s Git caching and container caching features were “absolute game changers,” reducing Git checkout times from several minutes to 30-40 seconds. Intelligent build cancellation and log customization further improved developer experience and operational efficiency.
The migration was conducted by a remarkably lean core team. “We built most of the Android pipelines and the iOS pipelines with two people,” said Struys. “You don’t need massive engineering resources to use Buildkite, but the scale is tremendous. We’ve got 170 plus engineers on it now, and most of our builds are running like 12 to 15 jobs in each field now.” It was also executed with exceptional care through a staged approach, including having shadow builds running in parallel to production systems to ensure a zero-risk transition. Buildkite’s team provided responsive support and delivered custom feature requests, including a GitHub App for GitHub Enterprise Server, throughout the process.
“Reddit’s successful migration exemplifies the transformative power of modern, composable CI/CD architecture,” said Dan Ring, Vice President of Product at Buildkite, who worked closely with the company on the migration. “When engineering organizations outgrow traditional CI/CD limitations, they need a platform that can deliver both immediate performance gains and long-term scalability. Reddit’s experience demonstrates what’s possible when you combine Buildkite’s high-performance hosted agents with our flexible, composable primitives. This isn’t just about faster builds, it’s about unleashing engineering teams to innovate at the speed their users demand.”
For more information, see Reddit’s blog post here.
