Improbable worlds is a privately funded London based start up working on a transformative new underlying technology for online games.
The team here is made up of some incredible young computer scientists from the best academic institutions, hedge funds and software houses in the country. We work primarily in Scala and C# on challenging greenfield problems in areas as distinct as distributed systems and procedural generation. The underlying technology is extremely exciting and the hope is that we can do certain things previously considered completely impossible in online experiences. We are also in talks with  AAA games talent from well known titles, with the intention of building  a game on top of our tech.
As a working environment we offer a few golden principles that you might find very refreshing:
Logic and careful thinking always trump seniority. Code quality matters just as much as productivity and much of the work here is challenging stuff nobody else has done before. 
Despite working on core tech, we get to build fun things! Working games and prototypes that stretch our platform and give core developers a chance to work with their own APIS. You even get to build cool stuff  in the interview :) ( Past candidates have created working train systems, pokemon clones, physical simulations….)
We are still somewhat in stealth mode but are happy to provide more details during the process. If you are not uncomfortable with an exceptionally challenging interview process, keen to work on hard problems in a flat, peer led team, then please email REDACTED_EMAIL.
Also we are currently based in a mansion with a pool…. Happy to relocate good candidates from overseas.
Ask HN: Who is hiring? (June 2013)