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Building leaderboard-cf: A Production-Ready Real-Time Leaderboard with Spring Boot, React, MySQL, Redis & K6

Arvind Kumar

3 min readJun 28, 2026

If you’ve prepared for System Design interviews, you’ve probably come across this question:

How would you design a real-time leaderboard for millions of users?

Recently, I shared a short Instagram reel explaining the high-level architecture behind this problem.

https://www.instagram.com/reel/DaDR1hKxtMt

Next iteration in that part

Can we build the complete system from scratch instead of stopping at the architecture?

That’s exactly what this series is about.

We’ll build a production-inspired leaderboard application step by step using modern technologies including React, Spring Boot, MySQL, Redis, and K6.

Instead of jumping directly to Redis or advanced distributed systems concepts, we’ll start with a simple implementation and improve it incrementally. Each part will introduce one architectural improvement while keeping the application fully functional.

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Arvind Kumar

Building leaderboard-cf: A Production-Ready Real-Time Leaderboard with Spring Boot, React, MySQL, Redis & K6

What We’ll Build

Written by Arvind Kumar

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