Collegevine·Software Engineer·Technical Phone Screen
May 2026
Collegevine software engineer interview with a coding problem centered on tree traversal and cost aggregation over a job hierarchy. The follow-up pushed into production concerns which I wasn't fully prepared for.
- You're given a JSON file of background job records, each with an id, optional parent_id, and duration_ms. Jobs can form a forest of trees. Write a function that computes the total cost (own duration plus all descendants) for every top-level job and returns the one with the highest total cost.
- What changes would you make to your solution for large-scale or production use, covering things like recursion depth, malformed data, cycle detection, and performance?
“My first instinct was recursive DFS and it worked fine for the example they walked through.”