MatchCircuit

Matching and messaging at scale means the backend has to handle bursty, real-time traffic — swipes, matches, messages — while still enforcing moderation and safety rules; a naive REST-only design wouldn't hold up once real-time chat entered the picture. MatchCircuit is the backend engine behind a dating app that handles exactly that: profile management, match-making logic, and real-time chat for a growing user base.

What I Built

• Matching engine — preference-based candidate scoring and swipe logic
• Real-time chat system for matched users
• Profile management — photo uploads, verification flows, and preference settings
• Moderation hooks — reporting, blocking, and content-filtering support
• Notification pipeline for push alerts on new matches and messages

Tech Stack

• Backend: Node.js, Express
• Database: MongoDB
• Real-time: WebSockets / Socket.IO
• Auth: JWT

Key Decisions

• Layered WebSockets on top of the REST API specifically for chat and match events, rather than making the whole backend real-time, since most operations (profile edits, preferences) didn't need that overhead
• Built moderation hooks (reporting, blocking, content filtering) into the core data model from the start rather than bolting them on later, since retrofitting safety features onto an existing matching system is far riskier than designing for them upfront
• Kept matching logic as a scoring function over structured preferences rather than a black-box model, so the ranking stayed explainable and tunable as requirements evolved

Outcome / Impact

A reliable, scalable backend built to handle matching and messaging for a large pool of active profiles without the real-time layer becoming a bottleneck.