Their HR contacted me and arrange an interview with a tech manager. The interview went well, mostly behavioural questions and your background. The problem is an take-home assignment after that, includes writing bash script, a simple code exercise using any language, a java exercise, and many theory question which you can easily use google to answer. Got them done quickly and they have feedback with unreasonable score. Ask how they score each question and never receive a reply. Also the same HR contacted me a month later and ask if I'm interested in the same role they're hiring. It seems that they does not keep track with candidate profile very well.