Intercontinental Exchange interview questions

I interviewed for a Java Backend Developer position in October 2025. The process consisted of a single, very technical round focused heavily on algorithms, Java coding, and backend security concepts. The interviewer asked me to implement programs using collections and common algorithms, then explain performance and how to harden the code with proper validation and security best practices. The difficulty was high, and they clearly expect very strong hands‑on experience with Java and secure backend design. The interviewer was professional and direct, but the pace was fast, so you need to be comfortable thinking aloud while coding. I was not selected, but the experience gave me a clear idea of their expectations and helped me understand how seriously they treat technical depth and security.