Grammarly·Software Engineer·Onsite - System Design / Architecture
Jul 2026
System design round at Grammarly for a software engineer role. The whole thing was a deep dive into building a collaborative spreadsheet product from scratch, think Google Sheets but you have to justify every decision out loud.
- Design an online spreadsheet service where multiple users can edit the same workbook simultaneously in real time.
- How would you design the data model for workbooks, sheets, cells, and revision history?
- Walk through your API design for opening a session, fetching a sheet, submitting edits, subscribing to live updates, and catching up after a reconnect.
- How do you handle conflict resolution when two users edit the same cell or insert rows and columns at the same time?
- How would you handle persistence, snapshots, and recovery if a server crashes mid-session?
- How would you approach formula recalculation when a cell that other cells depend on gets updated?
- How would you scale this system and keep latency low for users across different regions?
“This is a beast of a question.”