InterviewPrep Notes

InterviewPrep Notes is a free, ad-free online platform for practicing data structures, algorithms, SQL, system design, and other core topics that appear in technical interviews, with structured roadmaps and progress tracking.

What is InterviewPrep Notes?

InterviewPrep Notes is a curated collection of interview preparation materials built for software engineers. It offers concise notes, deep-dive explanations, real code snippets, and step-by-step roadmaps across DSA, SQL, Java, C++, Spring Boot, API design, OOP concepts, and cloud computing. The platform runs entirely in the browser on any device, and every resource is accessible without signup, paywalls, or premium tiers.

Key Features

• 100% free and ad-free — No signups, no premium tiers; all notes, code, and roadmaps are freely accessible forever.
• Structured roadmaps — Step-by-step learning paths for different experience levels, covering topics from arrays to dynamic programming.
• LeetCode-style progress tracking — Track your learning via a personal dashboard with streak counts, topic progress, and a weekly leaderboard.
• Curated interview notes — 115+ notes on the exact questions companies ask, including Big O, binary trees, stack vs queue, and the four pillars of OOP.
• SQL Practice Playground — Run real SQL queries in your browser with 13 challenges ranging from basic queries to window functions.
• Guess the Big O Game — A timed quiz that tests your ability to identify time complexity from code snippets.
• Mobile-friendly design — Fully responsive layout that works on phones and tablets for studying on the go.
• Regularly updated — Content refreshed based on interview trends and user feedback.

Who is it for?

• Software engineers preparing for tech interviews — Use the DSA and system design notes to brush up on algorithms, data structures, and architectural concepts.
• Computer science students — Follow the roadmaps to build a solid foundation in OOP, Java, C++, and SQL before applying for jobs.
• Career switchers entering development — Start with the beginner-friendly roadmaps and use the practice playgrounds to gain hands-on confidence.
• Experienced engineers brushing up — Jump straight to specific topics like Spring Boot microservices, API design best practices, or cloud computing with DevOps.

What can you do with InterviewPrep Notes?

• Interview candidates: Work through the DSA roadmap (81 topics across Arrays, Two Pointers, Sliding Window, Binary Search, and more) and track your progress to stay consistent.
• Data engineers and analysts: Use the SQL Mastery notes—covering joins, window functions, optimization, and indexing—to prepare for SQL rounds, and test yourself in the interactive playground.
• Backend developers: Study the Spring Boot and API design sections, including microservices, security, JPA, REST, and GraphQL, to prepare for project discussions.
• Anyone preparing for OOP interviews: Review the 4 pillars with code examples and practice 30+ common OOP interview questions.

How does InterviewPrep Notes work?

You start by picking a topic from the categories page (DSA, SQL, Java, etc.) or by following one of the 8 roadmaps. As you read through the notes, you can mark topics as done on the dashboard, which tracks your daily streak and progress. The interactive SQL playground and Big O game let you practice directly in the browser without installing anything.