Nikunj Garg
JAVA BACKEND DEVELOPER | _
// ABOUT_ME
Nikunj Garg
BCA student and Java Backend Developer building reliable, maintainable backend applications using Java 21, Spring Boot 3, and PostgreSQL.
Experienced in eliminating concurrency race conditions and inventory overselling via JPA/Hibernate pessimistic row locking and ACID transactions, building RESTful APIs, and implementing bidirectional WebSockets (STOMP) with stateless JWT Authentication & Refresh Token Rotation.
Proficient in relational database design (3NF), B-Tree indexing, Docker containerization, automated testing with JUnit 5, and cloud deployments on Render Cloud.
Bachelor of Computer Applications (BCA)
2025 – 2028Shri Guru Ram Rai University (SGRRU) — Dehradun, Uttarakhand
Cumulative CGPA: 7.48 / 10.0 (Semester 2: 7.96 / 10.0)
Core Curriculum & Specialization: Object-Oriented Programming (Java), Data Structures & Algorithms, Relational Database Management Systems (SQL/PostgreSQL), Operating Systems, Software Engineering & Clean Architecture.
// TECHNICAL_STACK
Core backend technologies, architectural patterns, and development toolchains.
Java 21 & Spring Boot 3
Core backend engineering in Java 21 LTS with strong OOP architecture, RESTful API design, Spring Boot 3.x microservices, Spring Data JPA, and Hibernate ORM.
PostgreSQL, Redis & Distributed Locking
Relational schema design (3NF), ACID transactions, distributed multi-locking via Redisson, Redis TTL lease management, and composite B-Tree query indexing.
Spring Security & JWT
Stateless authentication filters, database-persisted Refresh Token Rotation, BCrypt hashing, Role-Based Access Control (RBAC), and Bean Validation.
JUnit 5 & Concurrency Stress Testing
Extensive 70-test automated suite with JUnit 5, multithreaded concurrency stress testing (CountDownLatch, ExecutorService), distributed failure-mode suites, and Mockito isolation.
Docker & Render Cloud
Containerization with Docker and Docker Compose, zero-downtime cloud deployments on Render, automated health-check monitoring, Git version control, and Maven builds.
WebSockets (STOMP) & OpenAPI
Bidirectional full-duplex communication over STOMP WebSockets, delta synchronization, interactive OpenAPI / Swagger 3.0 documentation, and Cloudinary media pipelines.
// PROJECT_ARCHIVE
Production-grade backend architectures, hackathon deployments, and relational database systems.
DevTinder
Engineering Problem: Hackathon teammate discovery and collaboration suffered from disconnected channels, pairing friction, and arbitrary recommendation heuristics.
Architecture & Implementation: Architected the backend platform with Java 21, Spring Boot 3, and PostgreSQL. Engineered real-time bidirectional messaging via WebSockets (STOMP) with delta synchronization (?after={id}) and unread tracking over normalized schemas. Designed a dynamic candidate discovery service ranking profiles by shared skill counts in descending order, and hardened public APIs with stateless Spring Security, JWT & Refresh Token Rotation (token family replay defense), sliding-window IP rate limiting, and queue rewind.
Impact & Results: Containerized with a multi-stage Dockerfile and deployed to Render Cloud with automated health checks (/api/health), powering real-time chat, profile matching, and delta synchronization for a Next.js web client.
LibroSphere — Library Management & Reservation System
Engineering Problem: High-concurrency checkouts of limited, single-copy inventory created severe race conditions, duplicate allocations, and inventory underflow (TOCTOU anomalies).
Architecture & Implementation: Engineered a concurrency-safe asset lending and reservation backend in Java 21 and Spring Boot 3. Enforced Spring Data JPA pessimistic row locks (@Lock(PESSIMISTIC_WRITE) / SELECT ... FOR UPDATE) within atomic @Transactional boundaries. Architected a state-driven FIFO waitlist queue with 48-hour pickup expiration holds on returned assets, an idempotent midnight cron worker (@Scheduled) for tiered overdue fine calculations, and composite B-Tree indexing.
Impact & Results: Verified thread safety and ACID resilience through an automated 66-test JUnit 5 suite (100% pass rate), including multithreaded stress testing with 10 concurrent threads (CountDownLatch) confirming exactly 1 loan, 9 expected rejections, and zero underflow.
TicketWave — Distributed Seat Hold & Checkout Engine
Engineering Problem: Flash-crowd seat contention during stadium ticket spikes (e.g. Coldplay at Madison Square Garden) creates distributed deadlocks, double-booking race conditions, and database connection pool exhaustion.
Architecture & Implementation: Engineered a high-throughput distributed ticketing backend using Java 21, Spring Boot 3, Redis 7, and PostgreSQL. Implemented sub-millisecond distributed MultiLock seat allocation via Redisson with natural seat-ID sorting to eliminate deadlocks. Architected an in-memory Redis SETNX idempotency gate (IN_PROGRESS 120s / COMPLETED 24h replay) and decoupled simulated payment execution outside DB boundaries to protect HikariCP connection pools. Built a dual-tier inventory reclamation pipeline uniting real-time Redis keyspace expiration pub/sub with a 60-second scheduled PostgreSQL sweeper.
Impact & Results: Verified thread safety with 70 automated JUnit 5 tests, including 100-thread concurrent seat contention stress suites, idempotency storms, and architectural failure-mode simulations proving zero overselling under peak load.
// CREDENTIALS_&_ACHIEVEMENTS
Verified certifications, innovation recognition, hackathon leadership, and algorithmic milestones.
Smart India Hackathon (SIH'26 Internal Round)
Awarded Certificate of Participation in Smart India Hackathon 2026 (Internal Round), collaborating in a collegiate software development team to architect solutions for national-level problem statements.
Startup Innovation Recognition
Awarded Certificate of Recognition for pitching the multiplayer game startup concept "College Clash" at the Innovation & Incubation Centre (IIC), Shri Guru Ram Rai University, in collaboration with UCOST (Uttarakhand State Council for Science and Technology).
Algothon'26 Hackathon
Awarded Certificate of Participation in Algothon'26 organized by Algoxilla, actively demonstrating creativity, enthusiasm, and competitive problem-solving in building innovative software solutions.
Devlynix Buildathon 2.0
Engineered and deployed the backend for DevTinder in 72 hours under competitive hackathon pressure, implementing WebSockets (STOMP), relational PostgreSQL schemas, and cloud deployment.
Secretary — TechMantra Coding Club
Promoted from Core Member to Secretary within 10 months; organized 5+ hands-on coding bootcamps and technical workshops on Java, backend systems, and DSA for 120+ student developers, and co-coordinated collegiate tech events.
LeetCode Problem Solving
Actively practicing core Data Structures & Algorithms in Java on LeetCode (@Nikunjgarg12), focusing on arrays, strings, two-pointers, and linked list traversal algorithms.