7 Essential Topics for Software Engineering Interviews in 2025

Disclosure: This post includes affiliate links; I may receive compensation if you purchase products or services from the different links provided in this article. image_credit - Exponent Hello folks! Are you thinking about switching jobs in 2025 and wondering what topics and skills you should prepare for coding interviews? There's no denying that cracking interviews at tech giants like Google, Microsoft, and Amazon is challenging. But with a focused plan and preparation on the key skills that truly matter like Data Structures and Algorithms, System Design, Multithreading and Concurrency, SQL and Database Design, and solid problem-solving skills you can significantly boost your chances of success. If you go to Reddit and subreddits like /r/leetcode you will find many questions like : How do I prepare for Google or Microsoft software developer interviews? What topics should I focus on for technical interviews? How can I land a developer job at Amazon or Facebook? After seeing too many such queries on Facebook and LinkedIn, I decided to compile a comprehensive list of essential coding interview topics. In the past, I have also shared about Database Sharding, System design topics, Microservice Architecture, and System design algorithms and today, I am going to share system design questions for interviews. Whether you're targeting top-tier tech companies or looking to land your next software developer job at a startup or bank, this guide will give you a solid head start. Even if your dream job isn't at a FAANG company, preparing like you're aiming for one will put you far ahead of the competition. It's also important to note that different roles require different technical knowledge. For example: A Java developer interview requires strong Java fundamentals. A Python developer must know Python and frameworks like Django and Flask. A Web developer will be expected to demonstrate deep understanding of HTML, CSS, JavaScript, and frameworks like React, Angular, or Vue.js. However, the topics below are common to all interviews and are considered core programming skills. Every software developer is expected to master them. 7 Must-Know Topics for Tech Interviews in 2025 Here are the 7 key topics for any software Engineering, Software developer, Programmer, or Backend Developer interviews. 1. System Design System design is one of the most crucial and complex topics you'll encounter in interviews at companies like Google, Microsoft, Amazon, and Facebook. You'll be asked to design solutions from architecture to code, considering scalability, maintainability, and performance. System design interviews often include: High-level architecture (e.g., monolithic vs. microservices) Database choices (NoSQL vs. SQL) Scalability strategies (e.g., handling 10,000+ concurrent users) At the low level, expect questions about Object-Oriented Design, SOLID principles, and class relationships. Many candidates struggle with this, so you must prepare thoroughly. I recommend: Grokking Modern System Design for Software Engineers & Managers on Educative -- created by ex-hiring managers at top companies. System Design Interview – An insider's guide by Alex Xu -- a great foundational book. Grokking the System Design Interview on DesignGuru -- ideal for practicing system design interview problems. You can also get all of DesignGuru's Grokking courses at a big discount here. Use coupon code GURU for 30% off. 2. Data Structures You don't need to build web apps with Django or React, but you must know how a hash table works or when to choose a linked list over an array. Data structures are at the core of computer science. In interviews, you're often asked to: Choose the best data structure for a task Optimize time and space complexity Compare performance trade-offs You should be familiar with: Arrays Linked Lists Stacks & Queues Binary Trees & BSTs Hash Tables Graphs Heaps and Priority Queues Self-balanced trees (e.g., AVL) If you're looking to level up, I recommend: Algomonster -- 48 Patterns, Meticulously Curated by Google Engineers Data Structures and Algorithms: Deep Dive in Java -- for Java developers Coding Interview Patterns: Nail Your Next Coding Interview - for mastering coding interview patterns 3. Algorithms Knowing how to work with data structures is as important as knowing what they are. For instance: What's the difference between linear search and binary search? Why is O(log n) more efficient than O(n²)? You should be comfortable with: Sorting algorithms (quicksort, mergesort, heapsort) Searching algorithms Graph algorithms (shortest path, DFS, BFS) Recursion & backtracking Recommended resources: Introduction to Algorithms by Cormen et al. -- the bible of algorithms (advanced) Algorithms Specialization on Coursera -- taught by Stanford faculty Grokking Algorithms by Aditya Bhargava -- great beginner-friendly book

Apr 10, 2025 - 08:07

7 Essential Topics for Software Engineering Interviews in 2025

Disclosure: This post includes affiliate links; I may receive compensation if you purchase products or services from the different links provided in this article.

image_credit - Exponent

Hello folks! Are you thinking about switching jobs in 2025 and wondering what topics and skills you should prepare for coding interviews?

There's no denying that cracking interviews at tech giants like Google, Microsoft, and Amazon is challenging. But with a focused plan and preparation on the key skills that truly matter like Data Structures and Algorithms, System Design, Multithreading and Concurrency, SQL and Database Design, and solid problem-solving skills you can significantly boost your chances of success.

If you go to Reddit and subreddits like /r/leetcode you will find many questions like :

How do I prepare for Google or Microsoft software developer interviews?
What topics should I focus on for technical interviews?
How can I land a developer job at Amazon or Facebook?

After seeing too many such queries on Facebook and LinkedIn, I decided to compile a comprehensive list of essential coding interview topics.

In the past, I have also shared about Database Sharding, System design topics, Microservice Architecture, and System design algorithms and today, I am going to share system design questions for interviews.

Whether you're targeting top-tier tech companies or looking to land your next software developer job at a startup or bank, this guide will give you a solid head start.

Even if your dream job isn't at a FAANG company, preparing like you're aiming for one will put you far ahead of the competition.

It's also important to note that different roles require different technical knowledge. For example:

A Java developer interview requires strong Java fundamentals.
A Python developer must know Python and frameworks like Django and Flask.
A Web developer will be expected to demonstrate deep understanding of HTML, CSS, JavaScript, and frameworks like React, Angular, or Vue.js.

However, the topics below are common to all interviews and are considered core programming skills. Every software developer is expected to master them.

7 Must-Know Topics for Tech Interviews in 2025

Here are the 7 key topics for any software Engineering, Software developer, Programmer, or Backend Developer interviews.

1. System Design

System design is one of the most crucial and complex topics you'll encounter in interviews at companies like Google, Microsoft, Amazon, and Facebook. You'll be asked to design solutions from architecture to code, considering scalability, maintainability, and performance.

System design interviews often include:

High-level architecture (e.g., monolithic vs. microservices)
Database choices (NoSQL vs. SQL)
Scalability strategies (e.g., handling 10,000+ concurrent users)

At the low level, expect questions about Object-Oriented Design, SOLID principles, and class relationships.

Many candidates struggle with this, so you must prepare thoroughly. I recommend:

Grokking Modern System Design for Software Engineers & Managers on Educative -- created by ex-hiring managers at top companies.
System Design Interview – An insider's guide by Alex Xu -- a great foundational book.
Grokking the System Design Interview on DesignGuru -- ideal for practicing system design interview problems.

You can also get all of DesignGuru's Grokking courses at a big discount here. Use coupon code GURU for 30% off.

2. Data Structures

You don't need to build web apps with Django or React, but you must know how a hash table works or when to choose a linked list over an array.

Data structures are at the core of computer science. In interviews, you're often asked to:

Choose the best data structure for a task
Optimize time and space complexity
Compare performance trade-offs

You should be familiar with:

Arrays
Linked Lists
Stacks & Queues
Binary Trees & BSTs
Hash Tables
Graphs
Heaps and Priority Queues
Self-balanced trees (e.g., AVL)

If you're looking to level up, I recommend:

Algomonster -- 48 Patterns, Meticulously Curated by Google Engineers
Data Structures and Algorithms: Deep Dive in Java -- for Java developers
Coding Interview Patterns: Nail Your Next Coding Interview - for mastering coding interview patterns

3. Algorithms

Knowing how to work with data structures is as important as knowing what they are. For instance:

What's the difference between linear search and binary search?
Why is O(log n) more efficient than O(n²)?

You should be comfortable with:

Sorting algorithms (quicksort, mergesort, heapsort)
Searching algorithms
Graph algorithms (shortest path, DFS, BFS)
Recursion & backtracking

Recommended resources:

Introduction to Algorithms by Cormen et al. -- the bible of algorithms (advanced)
Algorithms Specialization on Coursera -- taught by Stanford faculty
Grokking Algorithms by Aditya Bhargava -- great beginner-friendly book

4. Concurrency

Concurrency is one of the most challenging and respected skills in coding interviews. It tests your ability to build efficient and resource-safe applications.

At a minimum, you should know about:

Threads and processes
Locks, critical sections, race conditions
Deadlocks and livelocks
Monitors and synchronization

Classic concurrency problems like Producer-Consumer or Dining Philosophers are must-practice.

If you're looking for a solid resource, I highly recommend:

Java Multithreading for Senior Engineering Interviews on Educative -- covers all the key concepts in Java.
Java Concurrency in Practice - Perfect for Java developers
The Art of Multiprocessor Programming - classic book on multi-threading

5. Database and SQL

Databases are used in almost every real-world application, so you'll be expected to know how to:

Model relationships (ER diagrams)
Normalize tables
Write efficient SQL queries
Understand joins, indexes, and execution plans

Key concepts:

Normalization and denormalization
Table scans vs. index seeks
SQL joins (inner, left, right, full)

Recommended resources:

Database Design Fundamentals for Software Engineers
SQL and Database Design By Kirill Eremenko on Udemy
Use The Index, Luke -- a fantastic resource for understanding indexing in SQL

6. Cloud Computing, Docker, and Kubernetes

While not always required, knowledge of cloud and containerization tools gives you a competitive edge.

Learn the basics of:

AWS Cloud Practitioner Certification
Docker for containerizing apps
Kubernetes for managing containers at scale

These skills are especially valuable for companies building microservices and cloud-native applications.

If you're new, start with:

Docker and Kubernetes: The Complete Guide by Stephen Grider

7. Object-Oriented Programming and Design (OOP)

OOP is a fundamental concept in coding interviews. You should be able to design modular, maintainable, and scalable solutions using:

Encapsulation
Inheritance
Polymorphism
Abstraction

You might be asked to model real-world systems like an online shopping cart, elevator system, or parking lot.

Recommended resource:

Grokking the Object-Oriented Design Interview on DesignGuru.io - for learning OOP design and concepts
- Codemia.io - solve OOP design problem online

Conclusion

These are the 7 essential topics every programmer should master to succeed in coding interviews at companies like Google, Microsoft, Apple, Facebook, and Amazon.

Along with technical know-how, I've also shared some of the best courses and books to help you learn and practice these topics effectively. Investing time in these areas will not only help you ace your next interview but also help you become a better software developer overall.

Good luck with your preparation!