I had an initial telephone interview where I was given a number of technical questions and was allowed to ask any questions of my own. From there I was invited for a two and a half hour technical and competency interview at their WeWork office in central London.
The interview itself included some questions around Spring, microservices and a small coding challenge. The face to face was very much a conversation, but if you mention something be prepared to be probed further.
The whole experience was incredibly smooth and stress free! The person dealing with my application (Nathan) was very helpful and they were an extremely pleasant company to deal with.