← Microsoft Interview Insights

Microsoft·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Jun 2026

Summary

Microsoft SWE interview that came down to a tree concepts question. Not much else to report, pretty standard technical screen.

Questions Asked (1)

Q1

What are the key concepts and operations associated with trees?

Algorithms & Data Structures
Author's notes

Pretty broad question and I kind of rambled through it.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

Start by defining a tree and its key terminology, then systematically cover the main types of trees and their operations, and finally discuss common algorithms and applications. Emphasize the trade-offs between different tree structures and their real-world uses.

Pro tip: Mention how trees are used in Microsoft products like file systems (NTFS uses B-trees) and databases (SQL Server indexes), showing practical awareness beyond textbook knowledge.

1. Define tree and basic terminology

Explain what a tree is: a hierarchical data structure with nodes connected by edges, no cycles. Define root, parent, child, leaf, subtree, depth, height.

2. Describe common tree types

List and briefly explain binary trees, binary search trees (BST), balanced trees (AVL, Red-Black), B-trees, heaps, tries, and segment trees.

3. Outline core operations

Cover insertion, deletion, search, traversal (in-order, pre-order, post-order, level-order), and rotation for balancing.

4. Discuss algorithms and applications

Mention tree traversal algorithms (DFS, BFS), lowest common ancestor, tree balancing, and applications like databases, file systems, and compilers.

5. Highlight trade-offs and complexities

Compare time complexities (e.g., BST vs balanced BST) and space usage, and explain when to use which tree structure.

Key Points to Mention

  • Tree terminology: root, parent, child, leaf, depth, height, subtree
  • Types: binary tree, BST, AVL, Red-Black, B-tree, heap, trie
  • Operations: insert, delete, search, traversal (in-order, pre-order, post-order, level-order)
  • Balancing: rotations, self-balancing trees, and their importance for performance
  • Time complexities: average vs worst-case for BST, balanced trees, and heaps
  • Applications: databases (B-trees), file systems, compilers (syntax trees), network routing

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.