Must-Know Data Structures for System Design Interviews
The data structures that matter in system design are different from what you learned in your algorithms course.
Arrays, linked lists, and binary search trees are building blocks, but they're not what interviewers are looking for. They want to know if you understand bloom filters, LSM trees, inverted indexes, and consistent hashing. These are the structures that power real distributed systems.
What makes these special? They operate at a different scale. They make deliberate trade-offs between memory, accuracy, and performance. They're designed for the realities of distributed systems: machines fail, networks partition, and you can't keep everything in memory.
This chapter covers the data structures that appear most frequently in system design interviews. For each one, I'll explain how it works, when to use it, and how to talk about it convincingly in an interview.