Since the beginning of the project, Lyra has been developed thinking of a simple way to add new features via a plugin system, leaving the core as small as possible.
The Lyra core team is currently working on hooks, allowing the community to interact with the Lyra processes easily.
That said, the Lyra core team is working on some official plugins to support specific features that might not be useful for the general public. That way, you will be able to bring in only the features you really need.
All the official plugins' source code is hosted under the LyraSearch organization.