Backend Developer @ BizLoom | Building scalable, secure systems in production

Currently architecting backend solutions for enterprise clients. Solved 1000+ algorithmic problems across competitive programming platforms. Passionate about performance optimization, security, and clean architecture.

Backend engineer specializing in scalable Node.js systems with a focus on security and performance. Currently shipping production features at BizLoom serving industrial clients.

Tech Stack: Node.js, TypeScript, PostgreSQL, MongoDB, Redis
Expertise: RESTful APIs, cryptography, database optimization, authentication systems, real-time features
Focus: Building secure, performant backends that scale

Production Experience: 8+ months building and maintaining enterprise systems
Problem Solving: 1000+ algorithmic problems solved across LeetCode, CodeChef, Codeforces
Performance: Reduced API response times by 60-70% through strategic optimization
Code Quality: Maintain 85-90% test coverage with comprehensive unit and integration tests
Security: Implemented zero-knowledge encryption and SRP authentication protocols

Production-ready security-first API with client-side encryption

The server can't read your passwords - even if compromised. Built with PostgreSQL and cryptographic protocols.

• Live Demo: zerolock.kuldeepdev.me
• Tech: Node.js + PostgreSQL + Web Crypto API + Argon2
• Security: SRP protocol, zero-knowledge architecture, TOTP 2FA, breach detection
• Impact: Demonstrates advanced cryptography implementation and security-first design
• Code: Repository • Production-ready with RBAC

Multi-tenant SaaS with GPT-4 integration for smart task optimization

Full-stack application with AI-powered task prioritization and real-time collaboration features.

• Live Demo: taskflow.kuldeepdev.me
• Backend: Node.js + MongoDB + Redis + WebSockets
• AI Integration: GPT-4 API for intelligent task suggestions
• Performance: 3-5x query improvement via Redis caching, <100ms response times
• Testing: 90%+ coverage with Jest/Supertest, CI/CD with GitHub Actions
• Code: Repository • Actively maintained

Full-featured REST API with payment processing

Production-ready e-commerce backend with complete order management and Stripe integration.

• Tech: Express + MongoDB + Stripe + JWT authentication
• Scale: 30+ RESTful endpoints managing 1000+ products
• Optimization: 40% query latency reduction through indexing
• Testing: 100% coverage for payment flows with Jest + Supertest
• Code: Repository

Backend Developer @ BizLoom (June 2025 - Present)
Building scalable backend solutions for enterprise clients

• Architecting backends for warranty management, inventory systems, and CRM platforms
• Designed RESTful APIs handling 500+ daily transactions with <200ms response times
• Optimized database queries achieving 60% performance improvements
• Implemented JWT authentication with role-based access control across multiple projects

Software Engineering Evaluator @ Outlier (Scale AI) (May - Sep 2024)
AI training data evaluation for leading AI labs

• Evaluated 250+ AI-generated code solutions for correctness and efficiency
• Reviewed algorithmic implementations focusing on time/space complexity
• Provided technical feedback on security vulnerabilities and performance improvements
• Contributed to training datasets for LLMs from leading AI companies

B.Tech in Information Technology - Ajay Kumar Garg Engineering College (2021-2025)
Supervised Machine Learning - DeepLearning.AI (Coursera) • Grade: 100%
Completed comprehensive course covering regression, classification, gradient descent using Python, NumPy, scikit-learn

• Security Engineering: Deep diving into cryptographic protocols and zero-knowledge systems
• System Design: Studying distributed architectures and scalability patterns
• Performance Optimization: Database query tuning, caching strategies, Node.js internals
• AI Integration: Building practical LLM-powered features with proper error handling

1000+ problems solved across platforms with consistent performance:

• LeetCode: cygnus07 • Top 15% globally • 450+ problems
• CodeChef, Codeforces: Active competitive programmer
• Specialization: Dynamic programming, graph algorithms, system design patterns

These aren't just exercises - I apply these patterns in production code daily.

Backend: Node.js, Express.js, TypeScript, REST APIs, WebSockets, Microservices
Databases: PostgreSQL, MySQL, MongoDB, Redis
Security & Cryptography: SRP Protocol, Argon2, Web Crypto API, JWT/OAuth2
Testing: Jest, Supertest, Postman
Tools: Git, GitHub, Railway, Vercel
Frontend: React.js, Next.js, Tailwind CSS
Languages: JavaScript, TypeScript, Python, SQL, C++

I'm interested in backend engineering roles where security, performance, and scalability matter. Open to remote opportunities.

Email: kuldeepsingh21070@gmail.com
LinkedIn: linkedin.com/in/kuldeep-singh-a61233271
LeetCode: leetcode.com/u/cygnus07
Location: Ghaziabad, India • Open to remote work