Changelog

New features, content, and improvements to returnzero.

Aug 2·New feature
PracticeCommunity

Book and join collaborative peer interview practice rooms with real-time canvas sharing and scheduling.

Aug 1·New feature
Coding

All DSA surfaces now support Python, JavaScript, and TypeScript side by side - code blocks, practice questions, and the live editor.

Jul 25·New feature
AISystem DesignPractice

A guided coach leads you through system-design problems step by step on a scaffolded canvas, with a debrief at the end. Available from any mobile system-design article or the problems catalog.

Premium
Jun 15·New feature
Dashboard

A redesigned dashboard with a Kanban-style prep board to track problems you're working on, an activity heatmap to keep your streak visible, and shared SWE plans - all in a cleaner layout.

Jun 13·New content
Companies

A new Anthropic interview-process guide and a deep article on AI safety considerations for interview settings.

Jun 13·New content
Coding

Five new practical coding challenges: Thread-Safe KV Store, Web Crawler, Image Processing Pipeline, Image Pipeline 2, and Persistent KV Store.

Jun 12·New content
Companies

Interview-process guides for 12 companies, with references. Guides are updated regularly as we get new reports from candidates - check back for new additions.

May 25·New content
Coding

18 deep articles covering data structures and algorithms fundamentals, 85 linked practice questions, and detailed animated visualizations for every concept - heaps, graphs, trees, sliding window, and more.

May 21·New feature
AICoding

Practice coding interviews with an AI interviewer in a live IDE, and review your past sessions on a dedicated My Sessions dashboard.

Premium
May 20·New feature
Study

Flashcard-style review cards with spaced repetition to reinforce system-design and core concept knowledge over time.

Premium
May 16·New feature
Coding

A structured Coding Interview Intro covering what coding interviews look like, what they test, and where to start - with guides on challenge shapes, the four-phase protocol, and code review rounds.

May 13·New content
MobileSystem Design

New core concept primers for Android system design - build systems (Gradle/Bazel), app size and delivery, and testing strategies.

May 13·New content
Coding

15 new interview-prep coding questions covering arrays, hash maps, sliding window, trees, stacks, and more - linked to their core concept articles.