Vivek kumar

Backend Engineer

Dhanbad, Jharkhand, India 0+ yrs exp 87 · Excellent

About

Backend Engineer with experience building Python backend systems using Django REST Framework, FastAPI, and PostgreSQL. Currently developing multi-tenant POS and inventory APIs with transaction-safe checkout, concurrency control, and cross-module integrations. Experienced in REST API development, relational database design, authentication, automated testing, and Docker.

Skills & Expertise (31)

Django Rest Framework Intermediate

7.0/10

Years Exp

SQL Intermediate

6.5/10

Years Exp

Python Intermediate

6.5/10

Years Exp

Postgresql Intermediate

6.5/10

Years Exp

FastAPI Intermediate

6.5/10

Years Exp

Git Intermediate

6.0/10

Years Exp

Docker Intermediate

5.5/10

Years Exp

Redis Beginner

5.0/10

Years Exp

GitHub Actions Beginner

5.0/10

Years Exp

Pytest Beginner

5.0/10

Years Exp

Postman Beginner

5.0/10

Years Exp

AWS Beginner

5.0/10

Years Exp

Azure Beginner

5.0/10

Years Exp

Operating systems Algorithms DBMS Computer Networks Data Structures Authentication & Authorization Caching Idempotency Transaction Management database design REST APIs React.js Databricks LINUX Pydantic SQLAlchemy Django C/C++

Work Experience

Founding Backend Engineer

Ralakde

May 2026 - Present

Building the POS backend using Django REST Framework and schema-per-tenant PostgreSQL, implementing 50 REST endpoints (61 HTTP operations) across transactions, sessions, registers, reporting, and settings. Implemented 15 transactional workflows including checkout, split/partial payments, voids, refunds, exchanges, hold/resume, cash reconciliation, and Quote/Sales Order creation. Built concurrency-safe checkout and inventory operations using atomic transactions, row-level locking, conditional stock updates, and database constraints to protect against overselling and conflicting updates. Integrated POS checkout across inventory, invoicing, customer payments, accounting, sales orders, quotes, taxes, and tenant services. Built and maintained 46 automated tests covering POS workflows and idempotency, including duplicate-request and concurrent-execution scenarios.

Software Developer Intern

Rockwell Automation

Feb 2025 - Aug 2025

Worked on backend services for the FTDM platform, building and maintaining REST endpoints in FastAPI within an existing service-oriented codebase. Built aggregation endpoints that combined data from several internal services into a single response, replacing the sequential calls the frontend was making for reporting screens. Extracted business logic from route handlers into shared service classes, and added Pydantic request and response validation with centralized exception handling so failures returned consistent error payloads instead of unhandled 500s. Profiled and load-tested slow endpoints to locate bottlenecks, then optimized the queries and code paths involved.