[FranzJosef]

Interesting! This framework tackles complex APIs with contract-first design and real integration testing - no mocking! Sounds like a strong solution for API sprawl, and the Apache 2.0 license is great. Performance and ease of learning are the key questions I'd have. Worth a look.

[Nick-Abbott]

Any framework does add overhead, and this is no exception. But Mosaic does a pretty good job of keeping things flowing. All of your API requests are running on totally separate threads with no shared memory to get blocked. The overhead is limited to a native ConcurrentHashMap lookup per tile invocation and the map instance is unique per API request, even when multiple are being handled at the same time. Shouldn’t be a concern for 99% of use cases.

As for the ease of learning, please, give it a try! I think it’s very straightforward but I’m obviously a bit biased. Would welcome good feedback to incorporate into a v1 release.