Apart from a user, I am also a contributor to the Zulip project, for the last ~7 months.
The community is very helpful and for getting started with open source development, I can't recommend a better place. You get really high quality code reviews, get to participate in meaningful discussions on features and the development goals of the project, and developers constantly share lots of knowledge in streams like #learning about software development, tech, git, best practices and so on.
Also, the documentation is very detailed and the codebase is very high quality. It's really easy to get started.
The community is very helpful and for getting started with open source development, I can't recommend a better place. You get really high quality code reviews, get to participate in meaningful discussions on features and the development goals of the project, and developers constantly share lots of knowledge in streams like #learning about software development, tech, git, best practices and so on.
Also, the documentation is very detailed and the codebase is very high quality. It's really easy to get started.
You can find the github org here: https://github.com/zulip