ServiceNow Staff Software Engineer: DSA, system design and achievements

The interview process took around a month and consisted of four interview rounds. I enjoyed the process, but it felt a bit long.

Rounds 1 and 2

Both of these rounds focused on DSA coding questions. They asked me N-Queens and Binary Tree Right Side View. They were tough questions, but I knew they liked to ask tree questions, so I had been practising them a lot. I needed that practice to finish within the time limit (30 minutes).

Round 3

This was a system design round where they asked me to design WhatsApp. They asked questions going deeper into how the architecture would scale. They also asked how user chats would be stored, how sessions would be managed, and how messages would be delivered to users who were online or offline.

Round 4

This was a DSA and managerial round. The DSA question was to design an LRU Cache, and the manager was very interested in my past achievements, specifically my biggest achievement at my previous company. They asked me to explain its technical details.