Notion Senior Software Engineer Interview Questions

1.Tell me about a time when user feedback completely changed how you approached a feature or project. What was the original plan, what did users tell you, and how did you pivot?

2.Tell me about a time when you advocated for removing or simplifying something users were already using. How did you make the case that less would be better?

3.Describe a feature you built that you later had to cut or significantly simplify based on user feedback. What convinced you to remove functionality you'd already shipped?

4.Walk me through a time when you had to deliver a project much faster than originally planned. How did you compress the timeline without compromising quality?

5.Tell me about the most significant technical project or initiative you said no to in the last year. What made you push back, and how did that decision play out?

6.Describe a situation where you initially dismissed user feedback as wrong or misguided, but later realized they were pointing to a real problem. What changed your mind?

7.Write a function that validates whether a block tree structure is valid according to Notion's rules. Consider parent-child relationships and circular references.

8.Implement a TypeScript function that merges two sorted arrays of Notion blocks, where each block has an ID and a timestamp. The result should be sorted by timestamp.

9.Our block storage engine is seeing high read latency during peak hours. The database team says queries are fast, but users report slow page loads. How would you debug this?

10.You're tasked with migrating a critical service from Python to TypeScript while maintaining zero downtime. The service handles block operations and serves 50K requests per second. What's your migration strategy?

11.You're implementing a new block type for Notion's editor that needs to support real-time collaboration. Walk me through how you'd design the data structure and handle concurrent edits from multiple users.

12.You need to add full-text search across a workspace that contains 10 million blocks with complex permission inheritance. How would you approach this?

13.Design a rollback system for Notion pages. Users should be able to revert any page to a previous state, but some pages have thousands of revisions. How do you make rollbacks fast while keeping storage costs reasonable?

14.You're building calendar sync for Notion Calendar that needs to stay in sync with Google Calendar, Outlook, and other providers. Events can be modified from either side, and conflicts need to resolve gracefully. How do you design this bidirectional sync?

15.You're building Notion's offline sync system. Users need to edit documents without internet, then sync changes when they reconnect. Multiple users might edit the same block offline and come back online simultaneously. How do you handle conflicts?

16.Design Notion AI's query system that needs to search across a user's entire workspace in under 200ms. The workspace contains 1M blocks of mixed content — text, databases, embeds. How do you make semantic search feel instant?

17.Design the permission system for Notion's workspace sharing. A single workspace can have 100K members with complex inheritance rules — pages can inherit from parent pages or have custom permissions. How would you ensure permission checks stay fast at this scale?

18.Walk me through how you'd build the notification system for Notion databases. When someone updates a row, you need to notify potentially thousands of subscribers across different channels — email, in-app, mobile push. How do you prevent a single database update from overwhelming your infrastructure?

19.Tell me about a time you had to convince an engineer who was more senior than you to change their approach on a technical decision. What was your strategy?

20.Tell me about a time when you built something primarily to help other engineers be more effective, even though it wasn't directly tied to user-facing features. What was your approach?

21.Describe a time when you had to mentor someone who wasn't on your direct team but whose success was critical to your project. How did you approach helping them level up?

22.Walk me through a time when you had to coordinate a complex project across multiple teams where everyone was already overcommitted. How did you get alignment and execution?

23.Describe a situation where you disagreed with your engineering manager's priorities or approach, but you still needed to maintain a good working relationship. How did you handle it?

24.Tell me about a time when you had to make a significant technical decision with incomplete information because waiting for perfect data would have delayed an important project. How did you approach it?

25.Notion's user base grew 10x in two years, but average session duration dropped 15%. Nothing changed in the product. How would you investigate what's happening?

26.Estimate how many API calls Notion processes per day. Walk me through your reasoning and key assumptions.

27.Notion is considering adding video calling to workspaces. How would you estimate the infrastructure cost and decide if it's worth building?

28.A Fortune 500 company wants to migrate 50,000 employees from Confluence to Notion. How would you estimate the timeline and identify the biggest risks?

29.Notion AI costs are growing faster than revenue. Each AI query costs us $0.02, users average 50 queries per month, but only 60% are on paid plans. How would you make this sustainable?

30.Notion is seeing 20% of new workspaces go inactive within 30 days. Each workspace setup takes engineering effort to provision. How would you identify what's causing abandonment and prioritize fixes?