Notion Coding Interview Questions
25 Notion coding interview problems with full optimal solutions — 14 easy, 10 medium, 1 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Notion interviewer values, and a FAQ section.
Showing 14 problems of 25
- #14easyfoundational
14. Binary Tree Inorder Traversal
Visit every node in a binary tree left-root-right — the same traversal order Notion's block engine uses to render nested page content, making this a direct window into how interviewers think about document structure.
- #17easyfoundational
17. Diameter of Binary Tree
Find the longest path between any two nodes in a tree — a metric Notion would use to measure the worst-case traversal depth across a workspace's page hierarchy, tying depth-first search to real document-graph reasoning.
- #2easyfrequently asked
2. Two Sum
Given an array and a target, return the indices of two numbers that add to the target. Notion uses this as a warm-up to gauge how quickly you reach for a hashmap.
- #3easyfrequently asked
3. Valid Parentheses
Given a string of brackets, return whether it's properly nested and matched. Notion asks this because their block editor literally validates nested markdown delimiters this way.
- #4easysometimes asked
4. Merge Two Sorted Lists
Merge two sorted singly-linked lists into one. Notion uses this to check whether you can write clean pointer code — relevant to merging two CRDT operation logs.
- #5easyfrequently asked
5. Maximum Depth of Binary Tree
Return the maximum depth of a binary tree. Notion uses this as a recursion warm-up — page nesting in their workspace is conceptually the same tree.
- #6easysometimes asked
6. Invert Binary Tree
Swap left and right children of every node in a binary tree. Notion uses this as a one-minute tree-traversal opener.
- #7easysometimes asked
7. Same Tree
Determine whether two binary trees are structurally and value-wise identical. Notion uses this to introduce the dual-recursion pattern needed for CRDT operation comparison.
- #8easysometimes asked
8. Symmetric Tree
Determine whether a binary tree is a mirror of itself. Notion likes this for the dual-pointer recursion that introduces tree-symmetry thinking.
- #9easysometimes asked
9. Balanced Binary Tree
Determine whether a binary tree is height-balanced (heights of children differ by at most 1). Notion uses this to test the single-pass DFS trick that avoids O(n^2) recomputation.
- #10easysometimes asked
10. Path Sum
Determine whether a root-to-leaf path sums to a target. Notion uses this as a base case before extending to tree-aggregate problems.
- #11easysometimes asked
11. Pascal's Triangle
Generate the first numRows of Pascal's triangle. Notion uses this as a row-building warmup before harder DP grid problems.
- #12easyfrequently asked
12. Best Time to Buy and Sell Stock
Find the max profit from a single buy/sell of one stock. Notion likes this because it introduces the running-min trick — useful in throttling and rate-limit calculations.
- #13easysometimes asked
13. Valid Palindrome
Determine whether a string is a palindrome after stripping non-alphanumerics and lowercasing. Notion uses this as a two-pointer warmup.
Related interview-prep guides
Replit for Tech Interviews in 2026: The Full-IDE Take-Home Guide
Replit-for-hiring is the full-IDE take-home format. The candidate gets a forked Repl, hours or days to ship a working project, and a commit history the reviewer will scrutinize line-by-line. This guide breaks down what Replit captures, what it doesn't, and how a desktop AI setup pairs with the multi-day window.