Here’s a comprehensive list of the Top 50 Technical Interview Questions & Answers for Developers, covering various topics like programming, data structures, algorithms, databases, system design, and more.
1. Programming Basics
- What is the difference between compiled and interpreted languages?
- Compiled languages (C, C++) translate code before execution, while interpreted languages (Python, JavaScript) execute line by line.
- What is the difference between an array and a linked list?
- Arrays have fixed size and allow random access, while linked lists have dynamic size but only sequential access.
- What are pointers?
- Pointers store memory addresses and allow direct memory access.
- What is recursion?
- Recursion is a function calling itself to solve a problem in smaller instances.
- What are the principles of OOP?
- Encapsulation, Abstraction, Inheritance, and Polymorphism.
2. Data Structures & Algorithms
- What is a stack?
- A Last-In-First-Out (LIFO) data structure.
- What is a queue?
- A First-In-First-Out (FIFO) data structure.
- What is a hash table?
- A data structure that maps keys to values using a hash function.
- What is the difference between BFS and DFS?
- BFS explores level by level, while DFS explores depth-wise.
- What is dynamic programming?
- A technique to solve problems by storing solutions to subproblems.
3. Databases
- What is normalization?
- Process of organizing data to reduce redundancy.
- What is an index in SQL?
- A data structure that improves database query performance.
- What are ACID properties?
- Atomicity, Consistency, Isolation, Durability—ensuring reliable transactions.
- What is the difference between SQL and NoSQL?
- SQL databases use structured tables, while NoSQL handles unstructured data.
- What is a primary key?
- A unique identifier for a database record.
4. System Design
- What is load balancing?
- Distributing traffic across multiple servers for efficiency.
- What is caching?
- Storing frequently accessed data for faster retrieval.
- What is a microservices architecture?
- A design pattern where applications are broken into smaller, independent services.
- What is CAP theorem?
- Consistency, Availability, and Partition Tolerance—only two can be achieved at the same time.
- What is sharding?
- Partitioning databases to improve scalability.
5. Web Development
- What is RESTful API?
