Be careful during their interview. The interviewer will trick you (with a witty "all candidates fail on this case") in a corner case mentioned orally but missing from the written test cases to support.
Also, be careful, the while the code for the pre-interview features all the logic to run tests case, the "human" interview will miss this feature and you'll lose time re-implementing a makeshift system during the call.
Ask HN: Who is hiring? (May 2018)