Trustly Senior Backend Engineer interview questions

The process took approximately 4 weeks and had 5 stages. It started with an HR screening: I was contacted via email and had the interview scheduled within a few days. The conversation was straightforward: background, motivation, and general culture fit. Nothing unexpected. From there, I moved into the technical interview, which was the most substantial stage. It was structured in clearly defined blocks, covering OOP and SOLID principles, Java internals, a SQL code review, a Java code review, and a system design challenge. Each block flowed naturally into the next, and the interviewer was genuinely engaged. It felt more like a technical discussion than an interrogation. The hiring manager interview came shortly after. It had a mix of architectural and behavioral questions, going deeper into how I applied concepts in practice rather than just whether I knew them in theory. The final stages were a background check and professional references submission, both handled smoothly and without unnecessary back-and-forth. Overall, the pace between stages was consistent. There were no long unexplained gaps, and communication throughout was clear.