We (~150 eng) build microservices in a polyglot environment (mostly Python, JS, and Go), all in a monorepo! We also build + deploy in containers with Jenkins, etc.
The structure looks something like this:
|-- third_party (third party libs)
`-- python
|-- libs (internally-written, common dependencies)
`-- application_name
|-- client (react app, connects to flask)
|-- server (flask app, connects to services)
`-- services (microservices)
We use a dependency-management + build tool (https://www.pantsbuild.org/index.html, we started before Bazel was public) to manage dependencies. Without pants, our repo would be a mess.Let me know if you have any questions, I'm happy to answer them! I'm super happy about our setup and eager to share it :)