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FULL-STACK DEVELOPER / BACKEND ENGINEER

Building systemsthat don't just work.They scale.

I design and build APIs, backend systems, payment infrastructure, and full-stack products engineered for real-world scale.

01WHO I AM

An engineer who thinks in systems.

I'm a full-stack developer with 3+ years of experience building scalable Node.js backend systems and payment platforms serving thousands of users.

My focus sits at the intersection of backend architecture and product engineering: RESTful APIs, authentication, databases, AWS infrastructure, and the frontend that ties it together. I care less about any single framework and more about how the pieces fit: where state lives, what a service owns, and what happens when an API has to change without breaking the clients depending on it.

system_profile.json
NameHarsh Rao
RoleFull-Stack Developer
Experience3+ Years
Primary DomainBackend Systems & Product Engineering
Core StackNode.js / React / Next.js / AWS
ScaleProducts serving 10,000+ users
status: available for new systems
02HOW I GOT HERE

Increasingly complex systems.

Three years, three engineering environments, each one raising the stakes on scale, compliance, or the number of moving parts a single service has to coordinate.

ABSS LLP

August 2025 - Present

Fullstack Developer

Building a SaaS ERP platform: custom billing systems, discount engines, and GST-compliant invoicing for inventory-heavy businesses.

SaaS ERP developmentCustom billing systemsDiscount enginesRazorpay integrationGST compliance APIsInventory managementBatch managementCRM workflows
  • Enabled generation of 5,000+ e-invoices and e-way bills
  • Reduced manual effort through streamlined workflows
  • Built flexible billing and pricing logic for a SaaS ERP platform

Enstead

September 2024 - July 2025

Fullstack Developer

Worked on EpicPay, a payment solutions platform serving 10,000+ users, building backend microservices designed to evolve without breaking existing clients.

Node.jsAWS LambdaBackend microservicesRESTful APIsAPI versioningJWT authenticationID verificationSelfie authenticationWebSocketsAdmin systems

Epoch Software Services

May 2023 - August 2024

Backend Developer

Worked across multiple products spanning mobility, marketplace, and travel, from real-time vehicle tracking to commission-based marketplace payments.

RAS

Car rental platform with end-to-end booking management, real-time vehicle tracking, and route optimization.

Node.jsReactMongoDBGoogle Maps API

EventBazaar

Marketplace platform connecting hair stylists and customers, with stylist verification, product management, and a 15% commission model.

Express.jsMongoDBGoogle APIsStripe

Destify

Intelligent travel booking platform covering flights, hotels, and activities.

Next.js
03SYSTEMS I HAVE WORKED ON

Engineering problems, solved end to end.

Four systems, four different pressures: flexible pricing, evolving payment APIs, real-time location, and a two-sided marketplace. Hover any diagram to trace how a request moves through it.

01ABSS LLP / SaaS ERP

Custom Billing & Discount Engine

The Context
ABSS LLP's ERP platform needed a billing layer flexible enough to handle varied customer pricing, add-ons, and India's GST compliance requirements, all without hardcoding logic per customer.
The Challenge
Pricing wasn't uniform. Customers needed custom discount rules, optional add-ons, and Razorpay-based payment collection, all while generating compliant e-invoices and e-way bills at volume.
The Engineering Approach
Designed a pricing pipeline that composes base pricing, add-ons, and discount rules as discrete, ordered steps rather than one tangled calculation, so new pricing logic could be added without touching existing rules. Integrated Razorpay for payment collection and wired the flow into GST-compliant invoice generation.
Node.jsRazorpayGST Compliance APIsSaaS ERP
5,000+ e-invoices and e-way bills generated
Reduced manual billing effort through streamlined workflows
CustomerSaaS ERPPricingEngineDiscountRulesAdd-onsRazorpayE-Invoice/ GST

Hover a node to trace its connections

02Enstead

EpicPay: Payment Infrastructure

The Context
EpicPay is a payment solutions platform serving 10,000+ users, requiring identity verification, secure authentication, and real-time client notifications on top of a Node.js backend.
The Challenge
The platform needed to keep shipping new capability (ID verification, selfie authentication, admin tooling) without breaking mobile clients already integrated against existing API contracts.
The Engineering Approach
Built backend microservices on Node.js and AWS Lambda behind versioned RESTful APIs, so new endpoints and behavior changes could roll out under a new version while older clients kept working against the version they were built for. JWT handled authentication; WebSockets pushed real-time state to clients and admin systems.
Node.jsAWS LambdaREST APIsAPI VersioningJWT AuthenticationWebSockets
Served 10,000+ users
Shipped ID and selfie verification without client-breaking changes
Mobile AppAPI Layerv1 / v2Auth (JWT)ID / SelfieVerifyNode.jsServicesAWS LambdaWebSocketNotify

Hover a node to trace its connections

03Epoch Software Services

RAS: Car Rental Platform

The Context
RAS is a car rental platform needing end-to-end booking management alongside live vehicle location, not just a booking form bolted onto a map.
The Challenge
Bookings needed to reflect real vehicle availability, and customers needed accurate tracking and routing once a rental was underway.
The Engineering Approach
Built the booking engine in Node.js against MongoDB for availability state, and layered the Google Maps API on top for live vehicle tracking and route optimization, keeping booking logic and location logic as separate concerns that meet at the vehicle record.
Node.jsReactMongoDBGoogle Maps API
End-to-end booking management shipped
Real-time vehicle tracking and route optimization
CustomerBookingEngineVehicleAvailabilityMongoDBGoogle MapsVehicleTrackingRouteOptimization

Hover a node to trace its connections

04Epoch Software Services

EventBazaar Marketplace

The Context
EventBazaar connects hair stylists with customers as a two-sided marketplace, requiring trust (verification), catalog management, and commission-based payments.
The Challenge
The platform needed to support two distinct user types plus admin oversight, verified stylist onboarding, product management, location-aware discovery, and a working commission model on top of real payments.
The Engineering Approach
Built on Express.js and MongoDB with distinct flows for customers, stylists, and admins. Stylist verification gated marketplace participation; Google APIs handled location-aware discovery; Stripe handled payment capture with a 15% commission split processed on top of each transaction.
Express.jsMongoDBStripeGoogle APIs
Two-sided marketplace with admin oversight shipped
15% commission model processed through Stripe
CustomerStylistVerificationAdminMarketplaceCoreProductMgmtLocationServicesStripe /Commission

Hover a node to trace its connections

04HOW I THINK

How I think about engineering.

01

Build for Change

Software requirements change.

Good architecture is not about predicting everything. It is about designing systems that can evolve without forcing a rewrite.

02

APIs Are Long-Term Contracts

An API is not just a route returning JSON. It is an agreement between systems.

Versioning, backward compatibility, consistency, security, and developer experience are the terms of that agreement.

03

Scale Is an Architecture Problem

Before adding more servers, understand the bottlenecks.

Data flow, database design, service boundaries, caching opportunities, and infrastructure constraints. Scale is decided long before load hits.

04

Complexity Should Be Intentional

Avoid unnecessary abstractions.

Use complexity only when the problem actually requires it.

06TECHNOLOGY ECOSYSTEM

The stack, as a system.

Not a list of badges. A request's actual path, from interface down to infrastructure, with tooling running alongside all of it.

FRONTEND
ReactNext.jsReduxTailwind CSS
BACKEND
Node.jsExpress.jsREST APIsJWT AuthenticationWebSockets
DATA
MongoDBMySQLSQL
CLOUD & INFRASTRUCTURE
AWS LambdaAWS EC2AWS S3DockerJenkins CI/CD
TOOLING
GitGitHubPostmanJiranpm
07LET'S BUILD SOMETHING

Have a system worth building?

Whether it's a new product, a complex backend problem, or a system that needs to scale, let's talk.