🚀 Hello, I'm

Bal Krishna

Full Stack Developer | Backend Specialist

Passionate Full Stack Developer with expertise in backend systems, robust application architecture, and payment solutions. I specialize in building scalable, secure web applications and e-commerce platforms using Node.js, Express.js, and modern databases. Experienced in developing complete solutions from discount APIs to role-based dashboards, with skills in payment gateway integrations (PayU, Stripe, Authorize.net), vendor onboarding systems, and comprehensive dashboard analytics — delivering clean, structured, and enterprise-level solutions.

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About Me

Building Robust Backend Solutions

I'm a Full Stack Developer currently in ConsultIT technologies Private Limited, with a strong passion for backend development. My journey began with frontend technologies, but I discovered my true calling in building robust server-side applications and architecting scalable systems.

I specialize in creating secure, maintainable applications with proper authentication systems, well-structured codebases, and enterprise-level features. My approach emphasizes clean architecture, comprehensive error handling, and code that's not just functional but also readable and maintainable by other developers.

Recently developed a complete payment aggregator platform featuring multi-gateway integration, vendor management systems, and real-time analytics dashboards. Built secure payment APIs, webhook systems, and document verification workflows while implementing Redux for efficient frontend state management.

I recently developed a complete eSIM e-commerce platform, building multiple APIs for discount management, user authentication, and product handling, along with responsive frontend pages using React and Tailwind CSS. This project showcased my ability to handle full-stack development with complex business logic.

When I'm not coding, you'll find me playing cricket,walking, reading about current affair or newspaper exploring new backend technologies, or diving deep into system design concepts. I believe in continuous learning and staying current with industry best practices.

2023 - Present

Full Stack Development Focus

Transitioned to full stack development with primary focus on backend systems, mastering Node.js ecosystem and database management.

2022 - present

Frontend Development

Started web development journey with React.js and modern frontend technologies, building responsive and interactive user interfaces.

Technical Skills

Backend Development (Primary)

Node.js

Express.js

JWT Auth

Role-based Auth

bcrypt

Crypto

Winston Logging

Cron Scheduler

Global Error Handling

RESTful APIs

Clean Architecture

Discount Systems

E-commerce Logic

Payment Gateway Integration

Webhook Development

API Security

Vendor Onboarding Systems

Document Verification APIs

Dashboard Analytics APIs

Multi-gateway Payment Systems

Database & ORM

MongoDB

PostgreSQL

MySQL

Mongoose

TypeORM

Database Design

Query Optimization

Indexing

Frontend Development (Secondary)

React.js

JavaScript

TypeScript

HTML5

CSS3

Redux

Tailwind CSS

Context API

Dashboard Design

AI Tools Integration

Formik

Responsive Design

UI/UX Basics

Tools & Cloud Services

Cloudinary

Git & GitHub

Postman

PayU Integration

Stripe API

Authorize.net

PayPal SDK

Redux State Management

VS Code

npm/yarn

Linux/Ubuntu

Featured Projects

Enterprise Payment Aggregator System

Key Backend Features Developed:

Multi-payment gateway integration (PayU, Stripe, Authorize.net, PayPal, PayG)
Dynamic gateway pooling system with vendor-specific credentials
Comprehensive dashboard APIs with analytics and reporting
Vendor onboarding with document verification APIs
Webhook handling for all integrated payment gateways
Role-based admin/vendor dashboard data management

Built complete payment infrastructure including transaction monitoring, vendor management, and real-time analytics. Implemented secure credential storage, webhook verification, and multi-level authentication systems.

Node.js Express.js MongoDB Payment APIs Webhook System JWT Auth Redux Analytics APIs Document Verification Vendor Management

API Documentation Backend Repository

Online Esim Selling Platform

Full-stack e-commerce platform for selling digital eSIMs with role-based dashboards, discount management system, and comprehensive admin panel. Built responsive pages including homepage, FAQ, and user/admin dashboards.

Node.js Express.js PostgreSQL React Tailwind CSS Context API JWT RESTful APIs

Live Demo Source Code

Full Stack Food Ordering Platform

Complete food ordering system with advanced backend architecture featuring JWT authentication, role-based access control, image upload with Cloudinary, order management, and payment integration.

Node.js Express.js MongoDB Mongoose JWT Cloudinary React

Live Demo Backend Code

Real-time Chat Application

Scalable chat application with Socket.io, JWT authentication, message persistence, user status management, and comprehensive error handling with Winston logging.

Socket.io Node.js Express.js MongoDB JWT Winston React

Live Demo Source Code

Secure Notes Management API

Enterprise-grade notes management system with advanced authentication, role-based permissions, data encryption, automated backups with cron jobs, and structured error handling.

Express.js MongoDB Mongoose JWT bcrypt Crypto Cron Jobs React

Live Demo View Code

Authentication Microservice

Robust authentication service with role-based access control, password policies, session management, rate limiting, and comprehensive security features for enterprise applications.

Node.js Express.js PostgreSQL TypeORM JWT bcrypt Rate Limiting Winston

Documentation Source Code