Open to opportunities

Rachit Roy

@rachitroy

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Full-stack developer building recommendation systems, cryptography-first apps, and ultra-fast databases.

India

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What I'm looking for

I’m looking for an entry-level full-stack or backend engineering role where I can build secure, high-performance systems—especially with recommendation/search, real-time features, and careful security/performance auditing—while growing into production-scale engineering.

I’m a full-stack developer with hands-on experience building production-grade applications across recommendation systems, applied cryptography, and database performance engineering. I built two full-stack applications end-to-end—architecting the React frontend and backend as one system—while keeping performance and security at the core of every decision.

In Buqs, I engineered a content-based recommendation engine with 1.6M+ similarity relationships across a 33,807-book catalog, delivering sub-millisecond to single-digit-millisecond query execution and a 99.5% database cache hit ratio. In Circle Chat, I implemented client-side end-to-end encryption using libsodium with Argon2id-based key wrapping and remediated security and efficiency issues after build—so I can ship real features without compromising trust. I’m seeking an entry-level full-stack or backend engineering role.

Experience

Work history, roles, and key accomplishments

Full-Stack Book Discovery

Buqs

Architected and built a full-stack book discovery platform with a content-based recommendation engine over a large catalog, including feed/search/recommendation endpoints optimized for low-latency execution and high cache hit rates. Implemented recommendation and search using weighted cosine similarity and hybrid PostgreSQL search (full-text + trigram similarity), plus an async analytics pipeline.

React Tanstack Query Express PostgreSQL Redis BullMQ Recommendation Systems Cosine Similarity Query Optimization Composite Indexing Full Text Search (Tsvector)Fuzzy Search (Pg_trgm Trigram Similarity)Cursor Based Pagination Infinite Scroll (IntersectionObserver)

Real-Time Encrypted Messaging

Circle Chat

Built an end-to-end encrypted real-time messaging application with a JWT-authenticated Socket.IO layer for live delivery, typing indicators, and presence tracking. Implemented client-side encryption using libsodium (X25519 + XSalsa20-Poly1305) with Argon2id-based key wrapping, and added secure encrypted image attachment handling via streaming to Cloudinary.