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Full Stack Software EngineerOpen to relocation & hybrid roles

Rahul Kumar
Singh

I design and build scalable backend services and real-time web applications — from live financial market feeds to compliance-sensitive healthcare platforms.

View selected work→Résumé (PDF)
4+
Years of experience
16
Largest cross-functional team led within
~40%
Load-time reduction via perf work
~30%
Fewer regressions after test automation

Based in Agra, Uttar Pradesh, India

01

About

Full Stack Software Engineer with 4+ years designing, developing, and supporting scalable backend services and web applications across fintech, healthcare, and real-time data domains. I work end-to-end — Python and Django on the back end, React and Next.js on the front — with a bias toward secure, well-tested, event-driven systems and the people who maintain them.

I've worked across financial services, healthcare, and real-time data — building REST APIs and event-driven WebSocket integrations, deploying on AWS with GitHub Actions CI/CD, and mentoring engineers on cross-functional teams of up to 16. I care about tracing production issues to their root cause, not their symptoms, and about leaving behind documentation that cuts the next person's ramp-up time.

Focus

  • Backend services & REST APIs
  • Real-time / event-driven systems
  • Front-end architecture & performance
  • Secure, well-tested delivery

Education

Master of Computer Applications (MCA), Computer Science

GLA University, Mathura

2021 — 2022

02

Selected Work

A few projects that show the range — from real-time market data to compliance-sensitive healthcare interfaces. Each opens into a full case study.

012025 — Present

ToolHaven

Privacy-first browser tools platform

Creator & Full Stack Engineer

Read case study toolhaven.app
ToolHaven homepage — editorial landing page with a search box over 500+ browser tools

A workshop of 500+ browser-based utilities — image, PDF, text, developer, finance, and design tools — that run entirely on the user's machine. No uploads, no accounts, no ads: everything processes client-side, works offline once loaded, and returns results in milliseconds.

  • Architected 500+ client-side tools (image compression, PDF merge/convert, JSON/JWT/Base64, calculators, generators) with zero server round-trips — files never leave the browser.
  • Engineered for privacy and speed: fully local processing, offline support after first load, and sub-50ms interactions.
  • Built a consistent, scalable component architecture and navigation across a large catalogue of independent tools.
  • Next.js
  • React
  • TypeScript
  • Tailwind CSS
  • Web APIs
  • Client-side processing
02Aug 2023 — Present

Quasar Markets

Real-time financial markets platform

Full Stack Engineer

Read case study app.quasarmarkets.com
Quasar Markets homepage — trading-floor imagery with the headline “Every market. Every signal.”

A real-time trading data platform delivering live stock and cryptocurrency feeds to users. I built backend REST APIs and data services in Python/Django during the initial build phase, then led front-end work on the WebSocket-powered live feeds.

  • Developed backend REST APIs and data services in Python/Django within a 16-person cross-functional team, powering real-time stock and crypto data delivery.
  • Led front-end development with WebSocket-powered live data feeds; boosted user engagement by ~30% through UI performance optimization.
  • Strengthened code quality through structured pull-request reviews and CI checks in GitHub Actions.
  • Python
  • Django
  • REST APIs
  • WebSockets
  • React
  • GitHub Actions
032025 — Present

HekaBio

Healthcare platform for clinical workflows

Front-End Lead

Read case study staging.heka.bio/sign-in
HekaBio homepage — the HekaBio wordmark and “Miracles through Partnership” tagline over a Mount Fuji sunset, above a line describing the company as a biopharma and MedTech in-licensing platform for Japan and APAC

A clinical-workflow platform for medical data visualization and analytics. I lead the front-end architecture, building accessible, WCAG-compliant interfaces and complex, compliance-sensitive modules within an 11-person distributed team.

  • Leading front-end architecture for medical data visualization and analytics with WCAG-compliant, accessible interfaces.
  • Delivered complex, form-heavy, compliance-sensitive modules and an interactive in-platform chat interface.
  • Manage code reviews, releases, and coordination within a distributed engineering team.
  • React
  • Next.js
  • TypeScript
  • Data Viz
  • Accessibility (WCAG)
Philosophy

I trace problems to their root cause, not their symptoms — and build systems that stay fast, tested, and legible for whoever maintains them next.

03

Experience

Mar 2023 — PresentCurrent

Front-End Lead (Full Stack Engineer)

Webmob Software Solutions Pvt. Ltd. · Mohali

  • Design, develop, and support scalable services for fintech and healthcare clients using Python (Django), Node.js, React, Next.js, and MongoDB within cross-functional teams of up to 16.
  • Built event-driven, real-time integrations with WebSockets/Socket.io for live market data delivery, and aligned solutions to security standards including JWT-based auth and secure API design.
  • Deployed and supported workloads on AWS (EC2, S3) and maintained CI/CD pipelines with GitHub Actions, improving release turnaround.
  • Introduced automated testing (Jest, Cypress), cutting regressions ~30%; optimized performance (code-splitting, lazy loading, memoization), cutting load times ~40%.
  • Mentored ~7 developers per project and authored onboarding & architecture docs, cutting ramp-up time ~40%.
  • Deployed AI conversational agents via Microsoft Copilot Studio + Teams and drove team-wide adoption of AI-assisted development as an internal standard.
Jan 2022 — Jan 2023

Full Stack Developer

ValueCoders Services Pvt. Ltd. · Gurugram

  • Delivered end-to-end features spanning a React front end and Node.js/Express/MongoDB back end in an Agile delivery environment.
  • Built a real-time chat application using WebSockets and Socket.io, supporting live, bi-directional messaging.
  • Developed a library of reusable React components and participated in code reviews and sprint planning.

Recognition

Top Performer

Webmob Software Solutions · 2024

Recognized for consistent high-quality delivery and client appreciation.

04

Capabilities

The tools and practices I reach for, grouped by where they live in the stack.

Languages

  • Python
  • TypeScript
  • JavaScript (ES6+)

Back-end & APIs

  • Django
  • Node.js
  • Express.js
  • REST API design
  • JWT auth
  • WebSockets / Socket.io

Front-end

  • React
  • Next.js
  • Redux Toolkit
  • React Query
  • Material UI
  • Tailwind CSS

Databases

  • MongoDB
  • Mongoose
  • Relational modeling

Cloud & DevOps

  • AWS (EC2, S3)
  • GitHub Actions
  • CI/CD
  • Vercel
  • Netlify

Testing & Quality

  • Jest
  • React Testing Library
  • Cypress
  • Code review
  • Root-cause debugging

AI-assisted dev

  • Claude (Anthropic)
  • GitHub Copilot
  • Copilot Studio
  • Cursor

Practices

  • Agile / Scrum
  • Component architecture
  • Security-aware dev
  • Stakeholder engagement
  • Python
  • Django
  • Node.js
  • Express.js
  • TypeScript
  • React
  • Next.js
  • Redux Toolkit
  • React Query
  • Tailwind CSS
  • MongoDB
  • GitHub Actions
  • Jest
  • Cypress
  • Vercel