Overall Buck and Bazel are quite similar as they are both converging to Starlark DSL. However there are still some differences: Buck is much more opinionated t

Overall Buck and Bazel are quite similar as they are both converging to Starlark DSL. However there are still some differences: Buck is much more opinionated than Bazel. Buck models slightly better C++ projects[1] and currently it's remote cache is more efficient[2]. Bazel is more extensible and offers also remote execution. Bazel has a bigger community and it's roadmap is public. There has been more than 350 C++ [4] libraries been ported to Buck for the Buckaroo Package Manager[3]. There are also technical details that manifest in some odd ways but are not significant. There is a nice paper by Simon Peyton Jones (creator of haskell) and others that goes into the design details [5] [1] https://github.com/bazelbuild/bazel/issues/7568 https://github.com/bazelbuild/bazel/issues/7568 [2] https://github.com/bazelbuild/bazel/issues/7664 https://github.com/bazelbuild/bazel/issues/7664 [3] https://github.com/LoopPerfect/buckaroo https://github.com/LoopPerfect/buckaroo [4] https://github.com/buckaroo-pm https://github.com/buckaroo-pm [5] https://www.microsoft.com/en-us/research/uploads/prod/2018/03/build-systems-final.pdf https://www.microsoft.com/en-us/research/uploads/prod/2018/0... Happy to go more into detail if desired