Code challenge - GCA on CodeSignal. I was only able to complete 2/4 of the questions during the allotted time (70 minutes) but I was still asked to continue. Technical phone interview - 60 minute phone call collaborating over Code Signal with an engineer discussing two whiteboard problems. Probably Leetcode medium difficulty. All done with pseudocode. Final Onsite Interview (remote due to COVID) - 4 different rounds each with one interviewer discussing system design, object oriented design, algo/data structures, and an informal chat with an engineer. The last round was a 2 hour session where the interviewer left me alone to code for 70 minutes then came back for a discussion about my implementation / opportunities for optimization. Every single person I talked to along the way seemed to be genuinely excited talk to me and collaborate. If I got stuck, they were empathetic and willing to support me. I got a call from the recruiter ~ 1 week after my final interview. She let me know that I didn't receive the position and walked me through each question with my feedback from the interviewers. She gave very great and detailed feedback.