Role
Backend Developer
Real interview questions with expert answers, plain-English explanations, and practical examples. (41 questions)
Google
Backend Developer
Databases
Explain database transactions, ACID properties, and how they ensure data integrity in a concurrent application.
Microsoft
Backend Developer
Concurrency
How do you ensure thread safety in a multi-threaded application, and what mechanisms are available beyond basic locks?
LinkedIn
Backend Developer
Authentication & Authorization
When would you choose OAuth 2.0 over API Keys for third-party access, and what are the key flows involved?
Zomato
Backend Developer
Data Structures & Algorithms
How would you implement a least recently used (LRU) cache, and what are its core components?
PayPal
Backend Developer
Message Queues
How do message queues ensure reliable delivery and what are the tradeoffs of at-least-once vs exactly-once processing?
Netflix
Backend Developer
Caching
When would you use different caching strategies like write-through or write-back, and how do you handle cache invalidation?
Microsoft
Backend Developer
API Design
How do you design an idempotent API endpoint, and why does it matter for payment retries?
Adobe
Backend Developer
Concurrency
Explain a race condition and how a mutex actually prevents it, with a concrete example.
Meta
Backend Developer
System Design
How would you design a rate limiter for an API, and how do token bucket and sliding window actually differ?
Capgemini
Backend Developer
Databases