Rajat Kapoor, Developer in Bengaluru, Karnataka, India
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Rajat Kapoor

Verified Expert  in Engineering

Software Developer

Bengaluru, Karnataka, India
Toptal Member Since
April 7, 2022

Rajat has been building web-based solutions for over seven years, working with numerous technologies best suited for solving particular problems. He also creates fun products like Android games, apps, Chrome extensions, and scripts to automate his day-to-day tasks. These projects have been the number one products on Product Hunt, and some are used by over 1,000 companies, including IBM, Salesforce, Gojek, and Toptal. His experience and skills make Rajat a great addition to any team.


Node.js, React, Next.js, Vercel, Amazon Web Services (AWS)...
MERN Stack, React, Slate, Less, Express.js, MongoDB, Node.js, TypeScript, HTTP...
React, Socket.IO, Django, Flask, Node.js, PostgreSQL, MongoDB, Tailwind CSS...




Preferred Environment

MacOS, Notion, Slack, Next.js, JavaScript

The most amazing...

...thing I've built is a Slack app that is used by more than 1,000 companies.

Work Experience

Product Engineering Lead

2022 - PRESENT
  • Developed the Neptune Editor (https://hashnode.com/neptune), using which the bloggers can create rich text content faster in a Notion-like editor.
  • Built a substack-like newsletter-related functionality into the product.
  • Managed a team of six developers and coordinated with PM and CXOs to drive product development.
  • Built a premium offering to monetize the product for writers on the platform by integrating with Paddle.
  • Migrated a lot of old code from legacy frameworks to Next.js using TypeScript and deployed it on Vercel.
  • Built the design system and component library to be used internally within the team to ensure design and feature consistency.
  • Merged a lot of independent repositories into a monorepo to support code-reusability.
Technologies: Node.js, React, Next.js, Vercel, Amazon Web Services (AWS), AWS Cloud Development Kit (CDK), AWS Lambda, Lambda Functions, Serverless, MacOS, Notion, Software Development, MongoDB, Tailwind CSS, TypeScript, Docker, Amazon CloudFront CDN, JavaScript, Full-stack, Full-stack Development

Software Engineer

2018 - 2022
  • Worked on the MERN stack written in TypeScript to develop new features for the state-of-the-art Qwilr editor and the whole platform. Established best practices for making an app scalable and fast.
  • Built the content and user management features so that users could arrange their documents into a file system like a directory structure and add permissions for users and user groups for that content.
  • Created interactive widgets for the WYSIWYG editor.
  • Managed the customer relationship management (CRM) integrations, including HubSpot, FreshBooks, QuickBooks, and others.
  • Ported a legacy codebase from CoffeeScript to TypeScript and migrated the UI from Angular to React.
  • Worked in the core product team, brainstormed ideas, and led the implementation.
Technologies: MERN Stack, React, Slate, Less, Express.js, MongoDB, Node.js, TypeScript, HTTP, Web, Docker, JavaScript, CSS, Full-stack, Full-stack Development, User Interface (UI), JSON Web Tokens (JWT), API Development, Vercel, MacOS, Notion, Software Development, Amazon CloudFront CDN

Software Engineer

2017 - 2018
  • Developed features for the research writing platform while working as a full-stack developer.
  • Built end-to-end product features, including the architectural design, back end, front end, CI/CD, and infrastructure setup to support them.
  • Created a reference management system and author's affiliation manager. Worked on analytics for the whole platform and collaborative writing using WebSockets.
Technologies: React, Socket.IO, Django, Flask, Node.js, PostgreSQL, MongoDB, Tailwind CSS, TypeScript, HTTP, Amazon CloudFront CDN, Web, Docker, SCSS, MySQL, JavaScript, CSS, Full-stack, Full-stack Development, SQL, User Interface (UI), JSON Web Tokens (JWT), API Development, MacOS, Software Development, MERN Stack, Express.js

Software Engineer

2016 - 2017
  • Integrated Eltropy with multiple partner APIs, including those that enabled us to build email and text messaging campaigns.
  • Built a Dropbox-like multiplatform application for syncing Eltropy files using Electron with React.
  • Created analytics that captured how much time users spend on each section of a web page.
  • Implemented RabbitMQ-based messaging infrastructure.
  • Deployed AWS EC2, DigitalOcean servers, and automation using Jenkins. Monitored website performance and security. Wrote the core business logic in the front and back end.
  • Interacted with clients to decide on the product roadmap, timelines, and resource allocation.
Technologies: Node.js, Grails, Electron, Go, HTTP, Web, React, JavaScript, CSS, Full-stack, Full-stack Development, SQL, User Interface (UI), JSON Web Tokens (JWT), API Development, MacOS, Software Development

Timely — Slack App for Automatic Time Zone Conversion

Single-handedly created and marketed a free Slack app to convert all times in your messages into all relevant time zones. Designed to solve my problem of working in a highly distributed team. Installed over 1600 Slack workspaces, including Salesforce, IBM, Toptal, DraftsKing, Gojek, Capterra, and Slack. Finally, processed over 25,000 messages daily and monetized it to $200.00 MRR.


Mockly is an easy-to-use ebook mockup generator. Perfect for generating simple 3d mockups for your info products and ebooks. With over 500 active and 25 paid users, and ended up being the number one "Product of the Day" on Product Hunt. Created, marketed, and monetized single-handedly.


Worked on the vision system of Range-IT Project to create a standalone, wearable, assistive device that processed stereo data in real time to extend the mobility of visually impaired people in an indoor environment. Captured the data using a 3D time-of-flight camera, filtered it using SoftKinetic's proprietary APIs, and analyzed using Point Cloud library using C++to detect stairs, walls, and doors up to a distance of seven meters

Display Engine for SimpleCV

Worked on creating an interactive rendering system for SimpleCV, which made it independent of the obsolete PyGame library. Developed the system using PyGTK and Cairo, along with a web counterpart compatible with IPython Notebooks using JavaScript and Processing.js.

Qwilr platform

Qwilr is a B2B SaaS platform that enables companies to create beautiful and dynamic business documents and proposals. These proposals open up as web pages and have built-in interactive widgets that allow users to accept payments or signatures.

Ruby Science Foundation — Numerical Integration, Minimization and Matrix Multiplication Modules

Worked on the integration, minimizations, and matrix libraries using Ruby and C++, adding more features and support for using GNU Scientific Libraries for faster computations. The project was implemented using C++ Ruby Foreign Function Interfaces.
2011 - 2016

Master's Degree in Mathematics

Birla Institute of Technology and Science, Pilani (BITS Pilani) - Pilani, India

2011 - 2016

Bachelor's Degree in Electrical and Electronics Engineering

Birla Institute of Technology and Science, Pilani (BITS Pilani) - Pilani, India


React, Node.js, API Development, Socket.IO, Slack API, Stripe


Notion, Slack, Amazon CloudFront CDN, Canvas, GTK+, AWS Cloud Development Kit (CDK)


Express.js, Django, Flask, Next.js, JSON Web Tokens (JWT), Electron, Grails, Tailwind CSS, Microsoft Kinect


Less, TypeScript, JavaScript, CSS, SQL, HTML, SCSS, Go, Python, Ruby, C++


MacOS, Web, Docker, Vercel, Amazon Web Services (AWS), AWS Lambda


MongoDB, MySQL, PostgreSQL


Software Development, MERN Stack, HTTP, Full-stack, Full-stack Development, Mathematics, Slate, User Interface (UI), Cairo, Foreign Function Interfaces (FFI), Computer Vision, 3D, Point Clouds, Object Recognition, Lambda Functions, Serverless

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