Perguntas de entrevista de vagas de Java Backend Developer da empresa Zalando

I was applying to Zalando on position Java back-end Software Engineer in June, 2016. First it was a call from HR asking general questions about my background and salary expectations. Then I was given a link to on-line coding challenge (codility.com/candidate-faq), different programming languages were available, I chose C++. Link expired in 4 days, when you started a codding challenge you had 3 tasks and 120 minutes. I solved all 3 tasks in 80 minutes. During the following calls I found out that my solutions passed 100% tests. After 2 weeks I was contacted by the same HR saying I solved all the tasks perfectly and they were happy to proceed. Next step were 2 skype interviews: one with Senior Software Engineer, second with founder and CTO. It turned out that I was applying not directly to Zalando, but to Metrigo, a startup in Hamburg recently taken over by Zalando. Both interviews were relaxed conversations about my background and company technologies. They needed Java Software Engineer, but I was a C++ SE. We agreed it should not be a problem and some transition time might be needed. As a follow up I got a call from HR offering 50k EUR salary with a possible promotion after I get Java skills. When I asked how could this salary change after I get Java skills (let's say one year), they cancelled their offer next day and decided not to proceed with me. All process took 3.5 weeks, online coding challenge, 2 skype interviews, 50k EUR offer, rejection on negotiation phase.