Hello everyone,
I often missed or forgot about upcoming contests across Codeforces, AtCoder, LeetCode, and CodeChef, so I built AlgoRadar an open-source Chrome extension that brings upcoming competitive programming contests from multiple platforms into one place.
✨ Features at a glance:
- Multiple Platforms: One unified interface for Codeforces, LeetCode, AtCoder, CodeChef, and more soon.
- Smart Filtering: Filter contests by platform and time range ("Today", "This Week", or "This Month") so you only see events that matter to you.
- Live Countdown Timers: See exactly how much time remains before registration or contest start, automatically adapted to your computer's local timezone..
- Fast Performance: Only 88 KiB in size, with background synchronization and caching to keep contest data fresh.
Technical Implementation & Architecture
For those interested in how it works under the hood:- Instant Popup Loading: Since data is pre-synchronized, opening the extension doesn't trigger multiple external API requests, resulting in fast popup loading.
- Server-side Synchronization: Instead of fetching schedules every time the popup opens, a backend periodically syncs contest data and serves cached results to the extension. This keeps popup load times fast while avoids repeated requests to external services
- Resilient Data Fetching: Some contest platforms are protected by Cloudflare, making scheduled fetches unreliable from standard environments. To handle this, the backend uses a serverless synchronization layer with cached responses, allowing contest data to remain consistently available even when direct scheduled fetches become unreliable.
The project is 100% open source. No ads, no analytics, no tracking, and no user credentials are collected. Feedback, bug reports, and feature suggestions are always welcome.
