It started with an initial call by one of the Lead Devs, followed by a pair programming session, they mentioned they also have a business inteligence of some sort of interview were they present a case and you come up with a solution along with a system design interview. The interview were nice and I certainly learned a lot but I did not understand why they asked nodeJs questions! or why system design after the second interviews HR that already alway answered late ( some cases with a follow up only) did not get back to me at all despite me sending two follow ups. very disrespectful!