The main thing to be aware of with Bazel is its sandboxing philosophy. Instead of using the files in place, it basically creates a copy of the relevant file structure for any given build (i.e. minus the files that might exist on a given folder but be irrelevant for a build). Because of this, it generally requires strict hermeticity guarantees from everything you're doing, so many things have to be done in a "Bazel way" (i.e. there are specific ways in which you're supposed to download dependencies and there are restrictions in terms of file creation in e.g. tests that might deal w/ I/O)

The way that Bazel approaches flexibility is by being programmable (via a Python-like language called Starlark). There are open source rulesets for various languages that you can use to get off the ground faster, but they are usually fairly opinionated, so if you want to deviate from the happy path, you're going to hit face first into a fairly steep learning curve about depsets, graphs, file/symlink permissions and the like.

Another "weakness" of Bazel is that it's not aware of ultra granular file-to-file dependencies out of the box (e.g. how Golang imports work vs Java's), so either you have to manage dependency graphs manually or you invest in wrapper tooling like gazelle to automate some of the BUILD file generation for you.