[Ruby Kaigi 2026] Faster Bundler, Happier Developers

Bundler has reliably helped the Ruby community install and manage dependencies for close to two decades, but with the announcement of Python's uv we found ourselves asking "Could Bundler be faster?". We took this opportunity to investigate and fix a multitude of performance issues now released in Bundler 4.

In this talk, we’ll dive into why Bundler is slow, what we are doing about it, and how the Ruby community can help. Our goals are to evolve Rubygems and Bundler in order to offer Ruby developers an exceptionally fast experience when running bundle install.

Transcript

1. Edouard Chin Faster Bundler, Happier developers
2. Edouard Chin Sta ff Developer @ Shopify Edouard-chin
4. ˒ Relevant ˒ Up to date ˒ Secure ˒ Fast Bundler is important for the Ruby ecosystem
5. Python UV First release
6. Could Bundler be much faster ?
7. ˒ What makes Bundler slow ˒ Optimizations we implemented ˒ You can help ! Bundler and RubyGems performance
8. bundle install in a new Rails application
9. Where is all this time being spent ? 13.337 total
10. 1. Resolve 2. Download 3. Install 3 core operations any package manager has to run
11. Resolving dependencies
12. RubyGems.org Compact Index API GET /versions GET /info/:gem_name
13. GET /info/road_to_rubykaigi Version number Dependencies Gem checksum Ruby/Rubygems Requirements
15. Gem::Version comparison is slow
17. Fast path for Gem::Version comparison
19. Git gems
20. Parallel git clones Benchmark with a Gem fi le containing 10 git gems
21. Download & Install
22. Workers fi ghting over a single h tt p connection
23. Bundler installation strategy is not e ff icient Worker is idle
24. Gem A Gem B Gem C Bundler waits for dependencies to be installed A will be dowloaded/installed when B is installed B will be dowloaded/installed when C is installed
25. Gem A Gem B Gem C Bundler waits for dependencies to be installed A will be dowloaded/installed when B is installed B will be dowloaded/installed when C is installed
26. 1. Gem C 2. Gem B 3. Gem A Gems are download and installed serially
28. Before After
29. Global gem cache .gem tarball will be dowloaded to ~/.cache/gem/gems
30. Global gem cache is opt-in for now
31. Let’s recap!
32. ˒ Faster resolution ˒ Faster gem download ˒ Faster installation ˒ Bundler / RubyGems share a global cache Bundler/RubyGems optimizations in 4.0.10
33. Bundler performance toolkit
34. 249 direct dependencies
35. 249 direct dependencies, benchmarks running on the RubyKaigi WIFI 2.60x faster
36. 40 git gems
37. Installing a brand new Rails application
38. Native extensions
40. cibuildgem is a new native precompilation toolchain
41. cibuildgem work fl ow in 4 steps Compilation
42. cibuildgem work fl ow in 4 steps Compilation Run the test suite against the precompiled binaries
43. cibuildgem work fl ow in 4 steps Run the test suite against the precompiled binaries Verify gems are installable Compilation
44. cibuildgem work fl ow in 4 steps Run the test suite against the precompiled binaries Verify gems are installable Release on RubyGems.org Compilation
45. Se tt ing up the GitHub work fl ow
46. Tweak the work fl ow to your needs
47. Let me share a last number
48. An experimentation to precompile popular gems with native extensions
49. Without precompiled binaries With 17 precompiled binaries Installing dependencies in a new Rails application
51. cibuildgem is a new native precompilation toolchain
52. Kudos
53. Thanks and enjoy RubyKaigi !