Hello, I'm Harshilsinh
React Frontend Developer
I build fast, accessible, and beautifully animated interfaces — turning product requirements into production-grade React and Next.js applications.
React • Next.js • TypeScript
Frontend engineer, detail-obsessed builder
I'm a frontend-focused software engineer with three-plus years of experience shipping enterprise web applications end-to-end — from component architecture and state management to performance tuning and accessibility. I care about the details most teams skip: layout stability, animation timing, bundle size, and interfaces that hold up under real usage, not just in a demo.
Component-driven, reusable architecture over one-off code
Performance and accessibility are features, not afterthoughts
Motion should clarify state, never distract from it
Scalable state management keeps large apps maintainable
Everything orbits React & Next.js
The core technologies I reach for daily, arranged by how close they sit to my day-to-day frontend work.
Technologies: React, Next.js, TypeScript, JavaScript, Tailwind CSS, Redux, Zustand, Node.js, Express.js, MongoDB, PostgreSQL, Git, Jest
A toolkit built for shipping
Grouped by where I use them most — frontend-heavy, with real backend, testing and tooling range behind it.
Frontend
- React
- Next.js
- TypeScript
- JavaScript
- Redux
- Zustand
- Tailwind CSS
- Material UI
- HTML5
- CSS3
Backend & Data
- Node.js
- Express.js
- Sequelize
- PostgreSQL
- MongoDB
- REST APIs
Testing & Quality
- Jest
- React Testing Library
- Accessibility
- Performance
Tooling & Collaboration
- GitHub
- Bitbucket
- GitLab
- JIRA
- Azure DevOps
- AWS (Lambda, S3)
- Figma
Where I've shipped
Three-plus years across two companies, building enterprise React and Next.js applications end-to-end.
Software Engineer
Vivansh Infotech
Building and maintaining enterprise web applications with a focus on responsive, state-driven UIs across operator and member-facing portals.
Key achievements
- Shipped multiple enterprise modules end-to-end using React.js, Zustand, Next.js, Tailwind CSS, and Material UI
- Delivered CRUD-heavy features with Redux-driven state management for consistently responsive user experiences
- Active participant in Agile ceremonies and code reviews across a cross-functional team
Responsibilities
- Developed enterprise web application modules using React.js, Next.js, Tailwind CSS, and Material UI
- Integrated REST APIs and implemented CRUD operations with efficient state management using Redux
- Collaborated with cross-functional teams in an Agile environment, participating in code reviews
- Used Git, Azure DevOps, and JIRA for version control and sprint management
Software Engineer
Tatvasoft
Owned end-to-end feature delivery on modern React/Next.js applications, from backend services to tested, production-ready UI.
Key achievements
- Built scalable backend services with Express.js and PostgreSQL using Sequelize ORM
- Wrote unit and UI tests with Jest and React Testing Library, raising confidence in shipped features
- Took ownership of end-to-end feature delivery, bug fixing, and performance optimization across sprints
Responsibilities
- Worked on modern web applications using React.js, Next.js, Redux, Tailwind CSS, Material UI, and Node.js
- Built and maintained scalable backend services with Express.js, PostgreSQL, and Sequelize ORM
- Integrated and consumed RESTful APIs efficiently across frontend modules
- Collaborated in Agile teams using JIRA, Bitbucket, and GitHub for sprint planning and version control
Enterprise applications, built end-to-end
Production platforms I owned frontend modules for, from component architecture through testing.
These are enterprise projects built for companies I've worked with, so I'm not able to share source code or a live demo here — happy to walk through the code and architecture in person.
Charge Point Operator
Real-time EV charging network management
A web application for managing EV charging stations, giving operators real-time access to station health, maintenance scheduling, and third-party integrations.
Co-Workspace Management
Operator and member portals for co-working spaces
A web application for managing co-working spaces, enabling workspace operations, resource allocation, bookings, invoicing, and tenant management through dedicated operator and member portals.
Smart City
IoT device management and analytics for infrastructure operators
A serverless, cloud-hosted platform that gives infrastructure operators a single place to manage IoT devices, watch sensor data come in on a live map, and set up rules that react to it automatically.
SIMS — Smart Inventory Management System
Multi-tenant inventory management with role-scoped access
A multi-tenant inventory platform where each tenant manages their own stock, orders, and users — with low-stock alerts, full order CRUD, and four roles (Super Admin, Admin, Manager, User) that are scoped per tenant, not just per account.
Afterwords
Confidential legacy-messaging platform (name changed for confidentiality)
A platform for recording messages to the people you love and having them delivered later — right after you're gone, or years from now on a specific date. Renamed here since the real project name is under NDA.
UI craft beyond the enterprise stack
Landing pages, marketing sites, and static builds where I could push visual polish and animation further.
Libraries I build and publish myself
Public npm packages, built and maintained independently — real repos, real releases, real documentation.
TreeKit
Open-source React tree/checkbox-tree component library
@treekit-ui/core
A TypeScript-first React component library for rendering hierarchical/tree data with first-class checkbox selection — the kind of UI used for file explorers, permission trees, category pickers, and nested multi-select forms.
- Cascading checkbox selection with real indeterminate state — actual native <input type="checkbox"> elements using the DOM's indeterminate property, not a styled div faking it
- Configurable propagation: checking a parent can cascade to children, checking children can bubble up to parents, both, or neither
- Controlled or uncontrolled API for expansion, checked state, and selection — React-idiomatic, your choice per use case
- Full WAI-ARIA tree semantics — roving tabindex, complete keyboard navigation, verified with automated jest-axe accessibility tests
universal-api-errors
One consistent, fully-typed error object — no matter which HTTP client or backend framework sent it
@harshilrajput/universal-api-errors + 4 more
An open-source TypeScript library that normalizes API errors from any HTTP client — Axios, fetch, and more — into one consistent, fully-typed error object. Published as 5 npm packages with a live docs site and interactive playground.
- Zero runtime dependencies in core — achieved via duck-typing rather than importing Axios/fetch types, so the core package works standalone with any HTTP client
- Strict TypeScript — exactOptionalPropertyTypes, noUncheckedIndexedAccess, zero any
- 91 tests, CI-verified on Node 22 and 24 via GitHub Actions
- Dual ESM/CJS builds with generated .d.ts via tsup
A process that scales with the project
The same six-step loop, whether it's a two-day landing page or a multi-month enterprise module.
Discover
Understand the product goal, users, and constraints before touching a single component — requirements, edge cases, and success metrics first.
Design
Translate requirements into component hierarchies, state models, and interaction patterns — wireframe the data flow, not just the UI.
Develop
Build with reusable, typed components and a clear state-management strategy, keeping the codebase scalable as features grow.
Test
Cover critical flows with Jest and React Testing Library, then validate accessibility, responsiveness, and edge cases by hand.
Deploy
Ship through CI with performance budgets in place — Lighthouse scores and bundle size are release gates, not afterthoughts.
Maintain
Monitor, fix, and iterate post-launch — performance regressions and bug reports get the same rigor as new feature work.
The path so far
Education, jobs, shipped projects, and where I'm headed next.
Started B.E. Computer Engineering
LDRP Institute of Technology & Research
Began a Bachelor of Engineering in Computer Engineering in Gandhinagar, Gujarat — first exposure to data structures, databases, and the web.
Graduated & joined Tatvasoft
LDRP Institute → Tatvasoft
Completed my engineering degree and joined Tatvasoft as a Software Engineer, moving straight into production React and Node.js work.
Shipped Charge Point Operator
Project · Tatvasoft
Delivered station management, user access, and invoicing modules for an EV charging network console, with Jest/RTL coverage on core flows.
Shipped Smart City
Project · Tatvasoft
Modernized a legacy IoT platform for infrastructure operators — migrated class components to hooks, upgraded to current Node.js LTS, and built out the rule engine, device management, and analytics modules.
Shipped SIMS
Project · Tatvasoft
Built a multi-tenant inventory management system with role-scoped access across four roles, configurable low-stock alerts, and full purchase/sales order CRUD.
Wrapped up at Tatvasoft
Tatvasoft
Closed out close to three years of end-to-end feature delivery, backend services, and testing practice.
Joined Vivansh Infotech
Vivansh Infotech
Started as a Software Engineer building enterprise web applications with React, Next.js, Zustand, and Azure DevOps-driven delivery.
Shipped Afterwords
Project · Vivansh Infotech
Delivered a confidential legacy-messaging platform — built the notifier-quorum confirmation flow and reworked video uploads around S3 multipart chunking, cutting a 1.8GB upload from 12–15 minutes down to under two.
Building Co-Workspace Management
Project · Vivansh Infotech
Currently building operator and member portals for a multi-location co-working platform, using Next.js, Zustand, and Tailwind CSS for booking and resource-management flows.
Deepening system design & architecture
Current focus
Focused on scalable frontend architecture, design systems, and mentoring — moving from feature delivery into technical ownership.
Senior / Lead Frontend Engineer
Future goal
Aiming for a senior or lead frontend role driving architecture decisions and design systems across an entire product surface.
Continuous learning, on record
Anthropic credentials I've completed on Claude Code, and how each one shows up in my day-to-day work.
Claude Code 101
A hands-on introduction to Claude Code — Anthropic's agentic coding CLI — covering its core tool loop, safe permission model, and how to direct it effectively on real codebases.
Claude Code in Action
An applied, project-based course on running Claude Code across real engineering workflows — multi-file changes, subagents, custom tooling, and verifying work end-to-end instead of trusting the first diff.
Numbers behind the work
1.8GB upload, down from ~13 min
Afterwords sent gigabyte video messages as one S3 request. Rebuilt on multipart upload with a Web Worker and a bounded queue: 12–15 min became 90–100 sec.
Product modules shipped
Across five enterprise platforms — station management, bookings, invoicing, inventory, and role administration.
Tests on universal-api-errors
Run on every push against Node 22 and 24 via GitHub Actions. The repository is public, so the number is checkable.
TreeKit, gzipped
A full tree component with cascading selection, keyboard navigation and virtualisation — and no runtime dependency beyond React.
Notes on frontend engineering
Short write-ups on the decisions behind the code — architecture, state, animation, and performance.