Backend interview prep

Interview prep, step by step

Six tools I built while preparing for backend interviews: DSA, Java, databases, operating systems, system design and machine coding. Each one stays a separate app with its own repo, and they all open here with shareable links.

AlgoScope: Step-by-step animated traces of 159 DSA interview problems, recorded from real Java runs, with Python and C++ versions.

Java Concepts Stepper: Debugger-style walkthroughs of the JVM, collections, OOP and design patterns, concurrency, Spring and JPA, with a quiz after every topic.

DB Concepts Stepper: 71 database topics from SQL to distributed systems, with runnable SQLite examples, auto-checked exercises and quizzes.

OS Concepts Stepper: 59 operating-system topics from system calls to containers, with in-browser scheduling, paging, disk and deadlock simulators.

Backpressure: System Design: A 12-week system design course with a live traffic simulator: load balancers, caches, queues and databases, with 29 lessons and labs.

The hub needs JavaScript; each tool above also works on its own page.

Drag the floating concepts onto the tool they belong to.

Made by Aditya Malu. Progress is saved in this browser. Signing in with Google also saves your daily streak and sort score to your account, and nothing else.