Netflix
Hard
Software EngineerModel advertiser intake database schema
System Design
19
0
July 17, 2025
Scalability Interview Questions
Scalability questions test whether you can design systems that handle growing load without degrading performance.
Expect questions on horizontal vs vertical scaling, database sharding, data partitioning strategies, and capacity planning.
Interviewers look for awareness of bottlenecks, trade-offs between consistency and throughput, and practical experience with scaling patterns.
1121Questions
202Companies
Easy 55 • Medium 583 • Hard 483Difficulty mix
Common scalability interview patterns
- Horizontal vs vertical scaling trade-offs
- Database sharding strategies (hash, range, geographic)
- Read replicas and write scaling
- Stateless service design for horizontal scaling
- Auto-scaling policies and capacity planning
- Data partitioning and rebalancing
Scalability interview questions
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eBay
Medium
Software EngineerDesign an Ad Assignment API
System Design
31
0
April 13, 2026
Adobe
Hard
Machine Learning EngineerOptimize LLM Training and Serving
ML System Design
23
0
May 25, 2026
Bridge.Xyz
Medium
Software EngineerDesign signup and login service
System Design
18
0
January 27, 2026
Tesla
Hard
Machine Learning EngineerModel other agents in simulation
ML System Design
17
0
February 12, 2026
Snowflake
Hard
Software EngineerDesign a distributed system end-to-end
System Design
23
0
September 6, 2025
Roblox
Medium
Software EngineerDesign favorites and social game recommendations
System Design
33
0
February 11, 2026
Uber
Hard
Software EngineerDesign driver heat map and discuss consensus
System Design
29
0
August 4, 2025
Palantir
Hard
Software EngineerDesign a scalable interview question bank
System Design
31
0
July 26, 2025
Instacart
Hard
Software EngineerDesign scalable inventory system and avoid races
System Design
28
0
September 6, 2025
Databricks
Hard
Software EngineerDesign an Online Bookstore
System Design
18
0
March 15, 2026
OpenAI
Medium
Software EngineerDesign a Multi-Tenant Online IDE
System Design
14
0
April 11, 2026
Apple
Medium
Software EngineerDesign ad click aggregator and file sync service
System Design
23
0
January 22, 2026
Uber
Hard
Machine Learning EngineerDesign real-time grid ETA for drivers
ML System Design
22
0
September 6, 2025
Figma
Medium
Software EngineerDesign an Async Job Scheduler
System Design
31
0
January 10, 2026
Datadog
Hard
Software EngineerDesign an image detection system
ML System Design
33
0
September 6, 2025
OpenAI
Hard
Software EngineerDesign a CI/CD system with live log streaming
System Design
20
0
December 15, 2025
DoorDash
Hard
Software EngineerDesign a notification system
System Design
29
0
September 6, 2025
Roblox
Medium
Software EngineerDesign a Scalable Likes System
System Design
24
0
April 1, 2026
Discord
Easy
Software EngineerDesign Slack-like chat system
System Design
28
0
March 1, 2026
Common mistakes in scalability discussions
- Jumping to scaling solutions before estimating actual load
- Ignoring the consistency implications of horizontal scaling
- Overlooking hot partition problems in sharding schemes
- Not considering the operational complexity of distributed systems
- Assuming vertical scaling is always simpler
How scalability questions are evaluated
Structured reasoning about load estimation and bottleneck identification matters most.
Show awareness of trade-offs rather than presenting a single solution.
Discuss failure modes and how the system degrades under extreme load.