I applied a while ago. I had two steps: screening, technical call. During technical call engineer from the company asked questions. I'm engineer with 10+ years of full stack experience, questions were easy for me. But for some reason they decided that my CSS is not strong enough and asked to update my resume. Interview process is broken, my CSS is amazing, maybe not perfect, but I have some very popular open source projects, and I have VERY good css reputation on stackoverflow. Also, the red flag for me was amount of tests they have. It's less than 1000. And it's for 5+ year project. It means that software development process is probably broken and working on such a product can be pain. Be careful.