Bazel and Buck are two popular build systems used by large software companies. Both systems offer a number of features that make them well-suited for building large, complex codebases, including:

• Multi-language support: Both Bazel and Buck support a wide range of programming languages, including Java, C++, Python, and Go.
• High-level build language: Both systems use a high-level build language that makes it easy to describe complex build dependencies.
• Caching: Both systems cache build artifacts to speed up subsequent builds.
• Parallelization: Both systems can parallelize builds to further speed them up.

However, there are also some key differences between Bazel and Buck:

• Bazel is more opinionated: Bazel has a more opinionated approach to build management, with a number of built-in features and conventions. Buck is more flexible, allowing developers to customize their build process more extensively.
• Bazel is more mature: Bazel has been around for longer than Buck, and is used by more large companies. Buck is still under active development, but it is catching up quickly.
• Bazel is more complex: Bazel is a more complex system than Buck, with a larger number of features and options. Buck is simpler to learn and use, but it may not be as powerful for large, complex projects.

So, which build system should you use? It depends on your needs. If you are looking for a powerful, mature build system with a lot of features, Bazel is a good choice. If you are looking for a simpler, more flexible build system, Buck is a good choice.

Here is a more detailed comparison of Bazel and Buck:

Bazel

• Pros:
  • Mature build system with a lot of features
  • Widely used by large companies
  • Good support for multi-language projects
  • Powerful caching and parallelization features
• Cons:
  • Complex build system with a steep learning curve
  • Opinionated approach to build management
  • Not as flexible as Buck

Buck

• Pros:
  • Simple, easy-to-use build system
  • Flexible build system with a lot of customization options
  • Good support for multi-language projects
  • Powerful caching and parallelization features
• Cons:
  • Not as mature as Bazel
  • Not as widely used by large companies
  • Some features are still under development

Ultimately, the best build system for you depends on your specific needs and preferences. If you are not sure which build system is right for you, I recommend trying both Bazel and Buck and seeing which one you prefer.