Sachin Gupta

Java Full Stack Developer

Mumbai, India 0+ yrs exp 82 · Excellent

About

Java Full Stack Developer with hands-on experience building backend applications using Java, Spring Boot, Spring Security, JPA/Hibernate, REST APIs, JWT, and PostgreSQL/MySQL. Experienced in React.js, Docker, authentication, RBAC, transaction processing, and production deployment. Built an AI-powered resume builder SaaS platform and a bank-style wallet system with secure authentication, idempotency, and audit logging.

Skills & Expertise (32)

React.js Intermediate

6.5/10

Years Exp

REST APIs Intermediate

6.0/10

Years Exp

OOP Intermediate

6.0/10

Years Exp

Git Intermediate

6.0/10

Years Exp

GitHub Intermediate

6.0/10

Years Exp

JavaScript Intermediate

6.0/10

Years Exp

Spring Boot Intermediate

5.5/10

Years Exp

Microservices Intermediate

5.5/10

Years Exp

JUnit 5 Intermediate

5.5/10

Years Exp

Java Intermediate

5.5/10

Years Exp

Docker Intermediate

5.0/10

Years Exp

Postman Intermediate

5.0/10

Years Exp

Mockito Intermediate

5.0/10

Years Exp

Exception Handling Intermediate

5.0/10

Years Exp

Postgresql Intermediate

5.0/10

Years Exp

Swagger Intermediate

5.0/10

Years Exp

MySql Intermediate

5.0/10

Years Exp

Tailwind CSS Intermediate

5.0/10

Years Exp

Streams API Intermediate

5.0/10

Years Exp

Collections Framework Intermediate

5.0/10

Years Exp

Spring Security Intermediate

5.0/10

Years Exp

JPA Intermediate

5.0/10

Years Exp

Hibernate Intermediate

5.0/10

Years Exp

Spring Data JPA Intermediate

5.0/10

Years Exp

Spring MVC Intermediate

5.0/10

Years Exp

SQL Intermediate

5.0/10

Years Exp

Supabase Intermediate

4.5/10

Years Exp

Eureka Intermediate

4.5/10

Years Exp

Firebase Intermediate

4.5/10

Years Exp

Railway Intermediate

4.5/10

Years Exp

Vercel Intermediate

4.5/10

Years Exp

Load Balancing Intermediate

4.0/10

Years Exp

Work Experience

Bank-Style Wallet & Transaction Ledger System

PayLedger

Feb 2026 - Present

Developed a bank-style wallet system with 11 REST endpoints covering wallet management, money transfers, transaction history, and admin operations, using Spring Boot, PostgreSQL, and JWT-based RBAC. Implemented atomic money transfers with balance validation and optimistic locking to prevent race conditions during concurrent transactions. Built idempotent transaction processing using unique transaction keys to prevent duplicate transfers during retries and network failures. Built transaction history and audit tracking to record successful, failed, and pending transactions; covered core logic with 12 JUnit test methods. Developed an admin dashboard to manage users, monitor system-wide transactions, view audit logs, and freeze or activate wallets.

AI Resume Builder

CareerDraft AI

Nov 2025 - Jan 2026

Built a JWT-secured Resume Builder & Analyzer SaaS platform exposing 33 REST endpoints that power resume creation, AI-based analysis, PDF export, and version-history workflows. Integrated Groq AI for ATS scoring and resume analysis, with PDF export and version history for multi-version resume management. Implemented JWT + email OTP authentication and role-based access control across Admin/User/Pro roles, along with Razorpay payment integration. Covered core backend logic with 12 JUnit/Mockito test methods; deployed backend on Railway and frontend on Vercel with HTTPS, CORS, and HttpOnly JWT cookies configured for secure client-server communication and authentication.

Web Developer

IMAXX TV Digital Pvt. Ltd.

Jul 2025 - Oct 2025

Implemented 4 video-quality options (240p, 360p, 480p, and 4K) for the OTT platform, giving viewers playback flexibility across different network conditions. Solely managed the company website end-to-end — React-based UI updates, JavaScript logic, content changes, and code deployment using Git/GitHub. Managed content operations for the OTT platform, including media uploads, video transcoding coordination, and metadata management via AWS S3 and an internal admin panel. Drove SEO and ASO efforts across web and mobile platforms — improving visibility on Google and growing reach through optimized notifications and feature updates, while managing app presence via Google Play Console. Coordinated with external development and content teams to ensure timely platform updates, bug fixes, and feature rollouts.