xAI
Medium
Software EngineerDesign a Durable Key-Value Cache with File-System Persistence
System Design
3
0
September 21, 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.
1155Questions
209Companies
Easy 59 • Medium 606 • Hard 490Difficulty 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
Filter and sort
Amazon
Hard
Software EngineerDesign document-tag classes with concurrency safety
System Design
4
0
July 31, 2025
Startups.Com
Medium
Machine Learning EngineerDesign NL-to-SQL performance optimization assistant
System Design
4
0
January 6, 2026
NVIDIA
Hard
Software EngineerExplain ML framework trends
ML System Design
2
0
August 4, 2025
Mercor
Medium
Machine Learning EngineerDesign a High-Demand Event Ticket Marketplace
System Design
3
0
July 8, 2026
Microsoft
Medium
Data ScientistDesign Product-Description Content Moderation at Marketplace Scale
ML System Design
3
0
May 4, 2026
Bytedance
Medium
Software EngineerDesign a Real-Time Auction Platform
System Design
2
0
April 14, 2026
Disney
Medium
Data EngineerDesign a Pipeline to Process a Billion Clickstream Events Per Day
System Design
4
0
February 20, 2026
Flipster
Easy
Software EngineerDesign 64-bit distributed IDs and a parking lot
System Design
5
0
February 12, 2026
Stripe
Medium
Software EngineerDesign an Idempotent Double-Entry Ledger
System Design
2
0
June 16, 2026
LinkedIn
Medium
Software EngineerDesign a CI/CD Task Scheduler
System Design
4
0
June 11, 2026
Meta
Easy
Machine Learning EngineerDesign an Online Coding Judge
System Design
2
0
February 27, 2026
Nash AI
Medium
Software EngineerDesign real-time delivery tracking with async updates
System Design
2
0
October 21, 2025
Amazon
Hard
Software EngineerDeep dive a resume project
ML System Design
4
0
July 15, 2025
Whatnot
Medium
Software EngineerDesign A WhatsApp-Style Messaging System
System Design
4
0
May 8, 2026
Atlassian
Medium
Software EngineerDesign a distributed rate limiter service
System Design
3
0
February 11, 2026
Snapchat
Medium
Software EngineerDesign a Column-Queryable KV Database
System Design
2
0
February 8, 2026
J.P. Morgan
Medium
Software EngineerDesign a URL shortener
System Design
3
0
January 29, 2026
Applied
Medium
Software EngineerDesign Sensor Data Processing With AI-Assisted Implementation
System Design
4
0
July 5, 2026
Robinhood
Medium
Software EngineerDesign a Reliable Distributed Job Scheduler
System Design
2
0
June 22, 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.