Hariom is available for hire
Hire HariomHariom Sharma
Verified Expert in Engineering
Front-end Developer
Dubai, United Arab Emirates
Toptal member since January 21, 2021
Bio
Hariom is a senior full-stack engineer and technical lead with over 10 years of experience in building SaaS platforms using React, Next.js, TypeScript, React Native, Node.js, GraphQL, PostgreSQL, and AWS. He has scaled GrowthDay from 10,000 to 400,000 users, built scheduling products for Google and Telefónica, led teams of 15+ engineers, and taken early-stage apps from prototype to production scale with practical AI features using Claude, OpenAI, and agentic workflows.
Portfolio
GrowthDay
JavaScript, TypeScript, React, React Native, Antd, Miro, Full-stack...
GrowthDay
JavaScript, TypeScript, React, React Native, Antd, Full-stack, Web Development...
Snappy Kraken
JavaScript, Web Development, ChatGPT, GitHub, APIs...
Experience
- React - 11 years
- TypeScript - 11 years
- Node.js - 8 years
- React Native - 6 years
- Amazon Web Services (AWS) - 4 years
- Next.js - 4 years
- Artificial Intelligence (AI) - 2 years
- Claude Code - 2 years
Preferred Environment
React Native, Node.js, React, TypeScript, Amazon Web Services (AWS), Next.js, PostgreSQL, Supabase, Cloudflare, Vercel, Python, Laravel, PHP
The most amazing...
...thing I've done is build and scale GrowthDay from 10,000 to 400,000 users while leading efforts across web, mobile, payments, live events, and analytics.
Work Experience
Technical Lead
2021 - PRESENT
GrowthDay
- Led 15+ engineers across the front end, back end, mobile, QA, and DevOps while staying hands-on in architecture, code reviews, debugging, and production delivery.
- Built and scaled GrowthDay’s web and mobile platform from 10,000 to 400,000+ users across Next.js, React, TypeScript, React Native, Node.js, GraphQL, AWS, and Stripe.
- Owned major product areas including subscriptions, checkout, onboarding, live events, courses, enterprise workflows, analytics dashboards, search, real-time chat/presence, and internal tooling.
- Built growth and experimentation systems using Statsig, Mixpanel, RudderStack, GTM, Meta Pixel/CAPI, Appsflyer, and Braze to understand funnel drop-offs and improve conversion.
- Improved checkout conversion by 9%, reduced payment/SCA failures by 25%, improved campaign/onboarding load times by 30%, and helped scale AWS infrastructure by 20x while reducing cost by 25%.
- Helped run production releases across web and mobile, including release readiness, incident debugging, performance work, and coordination across product, design, marketing, finance, and leadership.
Technologies: JavaScript, TypeScript, React, React Native, Antd, Miro, Full-stack, Web Development, User Experience (UX), Amazon Web Services (AWS), Full-stack Development, PostgreSQL, Next.js, Mixpanel, Braze, RudderStack, Kajabi, RevenueCat, Statsig, Keycloak, Stripe, GitHub Actions, CAPTCHA, Facebook Pixel, Google Tag Manager, ChatGPT, Google Analytics, Analytics, Leadership, Architecture, GitHub, Vercel, OpenAI API, APIs, Payment Gateways, Supabase, Apple Pay, API Integration, CSS, Figma to HTML, Responsive UI, HTML, Google Pay, Technical Leadership, Automation, n8n, AI Tools, Anthropic, Claude API, Mobile, Reporting, Dashboards, Databases, Tailwind CSS, Large Language Models (LLMs), Artificial Intelligence (AI), REST, Claude Code, MySQL, Payments, Mobile Architecture, Stripe Connect, Claude, Codex, Claude Agent SDK, AI SDK, Tailwind UI, Shadcn UI, Agentic AI, Gemini, Cloud, Generative Artificial Intelligence (GenAI), NoSQL, Audio, JSON, Data Structures, Responsive Web Design (RWD), Security, Expo, Mobile Design, Mobile UI Design, UI Animation, UI Design, Data Modeling, Database Structure, Scalability, Scalable Architecture, OpenAI, Videos, Webhooks, CI/CD Pipelines, CMS, Design Systems, Figma to React, Component Libraries, Contentful, Education Technology (Edtech), AI Engineering, Agentic Coding, Cursor AI, WebRTC, OpenRouter, Elasticsearch
Lead Front-end Engineer
2021 - 2021
GrowthDay
- Built most of the original GrowthDay web platform from scratch using React, Next.js, TypeScript, GraphQL, AWS, and a reusable front-end architecture.
- Rebuilt fragmented product surfaces into a consistent product experience across onboarding, courses, subscriptions, live events, dashboards, and account flows.
- Built analytics instrumentation across Mixpanel, RudderStack, Google Analytics, GTM, Meta Pixel, and product dashboards.
- Worked closely with product, design, and leadership to turn early product ideas into shipped production features.
- Established front-end patterns for routing, state management, API integration, performance, reusable components, and release quality.
Technologies: JavaScript, TypeScript, React, React Native, Antd, Full-stack, Web Development, User Experience (UX), Mixpanel, Keycloak, Kajabi, Stripe, RevenueCat, GitHub Actions, CAPTCHA, Facebook Pixel, Google Tag Manager, ChatGPT, RudderStack, Google Analytics, Analytics, Leadership, Architecture, GitHub, Vercel, APIs, Payment Gateways, Apple Pay, API Integration, CSS, Figma to HTML, Responsive UI, HTML, Google Pay, Technical Leadership, Automation, AI Tools, Mobile, Reporting, Dashboards, REST, Claude Code, Payments, Mobile Architecture, Claude, Codex, Claude API, Cloud, Audio, JSON, Data Structures, Responsive Web Design (RWD), Security, Expo, Mobile Design, Mobile UI Design, UI Animation, UI Design, Videos, CI/CD Pipelines, CMS, Figma to React, Component Libraries, Contentful, Education Technology (Edtech), WebRTC
Senior Front-end Engineer
2021 - 2021
Snappy Kraken
- Streamlined and improved front-end development processes for creating complex interactive campaigns.
- Led the development of a new front-end team by creating interview tests, directly interviewing and onboarding two new developers, creating a central development knowledge hub, and championing best practices to reduce the ramp-up time.
- Tracked and fixed bugs using Asana as a reporting tool.
Technologies: JavaScript, Web Development, ChatGPT, GitHub, APIs, Customer Relationship Management (CRM), API Integration, CSS, Figma to HTML, Responsive UI, HTML, AI Tools, REST, Webflow, JSON, Responsive Web Design (RWD), UI Animation, UI Design
Lead Software Engineer
2020 - 2021
Appointy
- Led development of Saastack, a SaaS platform with modular, Plug'n'Play, multi-repo architecture, and basic prebuilt apps complete with features for RTL, custom apps integrations, multilingualism, and accessibility.
- Developed new features for Saastack to support client billing, management, people management, and reporting using React, Material-UI, Relay, and Graphql.
- Enhanced performance, dynamicity, and customization by driving new enhancements, including caching to reduce load times from 15 seconds to less than a second.
- Created a Command-line-Interface for the scaffolding app by leveraging Relay as a Graphql client to eliminate codebase set up times and drive development efficiency and productivity.
- Decreased development time and maximized development flexibility by introducing a hook-based architecture to enable apps and features to be hooked anywhere within the app at runtime.
- Designed i18n library and prebuilt components to convert the app into multiple languages, currencies, and formats supported in countries worldwide.
Technologies: Responsive Coding, User Interface (UI), Front-end, HTML5, Yarn, WebSockets, SCSS, Agile, React Router, JSON Web Tokens (JWT), Gulp, Next.js, SaaS, Git, WebStorm, Sass, JavaScript, Front-end Development, Front-end Architecture, ESLint, Formik, Material UI, ECMAScript (ES6), Storybook, Styled-components, Node.js, Babel, Webpack, Relay, GraphQL, TypeScript, React, Progressive Web Applications (PWAs), Web Development, User Experience (UX), Full-stack Development, Mixpanel, Stripe, GitHub Actions, CAPTCHA, Analytics, Leadership, Architecture, GitHub, OpenAI API, APIs, Payment Gateways, API Integration, CSS, Figma to HTML, Responsive UI, HTML, Technical Leadership, Reporting, Dashboards, Databases, REST, MySQL, Payments, Cloud, JSON, Data Structures, Security, UI Animation, UI Design, Data Modeling, Database Structure, Scalability, Scalable Architecture, Webhooks, Web Content Accessibility Guidelines (WCAG), CI/CD Pipelines, WCAG 2, Design Systems, Figma to React, Component Libraries, React Redux
Engineering Design Lead
2018 - 2020
Appointy
- Developed Appointy's small-to-large business multi-layered scheduling tool with multiple views, time zone support, drag-drop events, and event positioning for 1MM users with Angular, Angular Material, and NGRX Store.
- Spearheaded front-end development for billing, staffing, business hours tools, calendars, and shift management and designed the guidelines based on best practices to maximize efficiency with a team of eight developers.
- Evaluated libraries and tools for integration, including FullCalendar to reduce development time from a year to one month and Angular Framework to help further optimize development and code quality.
Technologies: Responsive Coding, User Interface (UI), Front-end, HTML5, Yarn, WebSockets, SCSS, NgRx/store, RxJS, Agile, React Router, JSON Web Tokens (JWT), jQuery, Gulp, Next.js, SaaS, REST APIs, Git, WebStorm, Sass, JavaScript, Front-end Architecture, ESLint, Formik, Material UI, ECMAScript (ES6), Front-end Development, Storybook, Styled-components, Node.js, Babel, Webpack, Relay, GraphQL, TypeScript, React, Web Development, User Experience (UX), Mixpanel, Stripe, GitHub Actions, CAPTCHA, Analytics, Architecture, GitHub, APIs, Payment Gateways, API Integration, CSS, Figma to HTML, Responsive UI, HTML, Reporting, Dashboards, REST, Payments, JSON, Data Structures, UI Animation, UI Design, CI/CD Pipelines, Figma to React, Component Libraries, React Redux
Mobile Application Developer
2016 - 2020
Accevate Technologies (Freelance)
- Developed Android and iOS education management apps that enable students to attend online classes and view messages and documentation, teachers to manage student work, and management to oversee operations using Ionic, Cordova, and Angular.
- Integrated Cordova plugins, including SMS reader and file downloader, to secure private data and improve the user experience.
- Implemented Firebase cloud messaging to send relevant notifications to students and teachers for assignments and tasks.
Technologies: User Interface (UI), Front-end, HTML5, Yarn, WebSockets, Front-end Architecture, Expo, Agile, Formik, JSON Web Tokens (JWT), Gulp, REST APIs, Git, Slack, WebStorm, Sass, Redux, JavaScript, ECMAScript (ES6), React, Firebase Cloud Messaging (FCM), Cordova, React Native, SCSS, TypeScript, Ionic, Angular, Progressive Web Applications (PWAs), Full-stack, Web Development, GitHub, APIs, Firebase, API Integration, CSS, Mobile, REST, JSON, Mobile Design, Mobile UI Design, UI Animation, UI Design
Associate Product Developer
2017 - 2018
Appointy
- Advised and oversaw the front-end development for clients by creating user flows, product roadmaps, and features with a team of four front-end developers.
- Created a new product that coordinated fitness classes, restaurant, and spa scheduling for Google, focusing on accessibility.
- Built a room conference scheduling system for Telefonica, one of Spain’s largest telecom companies, with features for managing rooms, schedule calendars, staffing, and CMS/TMS integrations using Angular, Angular Material, and NGRX Store.
Technologies: Responsive Coding, User Interface (UI), Front-end, HTML5, Yarn, WebSockets, Front-end Architecture, SCSS, Agile, JSON Web Tokens (JWT), jQuery, Gulp, Babel, SaaS, REST APIs, Git, WebStorm, Sass, Front-end Development, NgRx/store, Redux, RxJS, ECMAScript (ES6), JavaScript, TypeScript, Webpack, Angular, Web Development, GitHub, APIs, API Integration, CSS, Figma to HTML, Responsive UI, HTML, Reporting, REST, JSON
Intern
2015 - 2017
Appointy
- Wrote scripts for task automation for Appointy 9.0 with SASS, Tree Shaking, and AOT that saved at least six hours of development time each week, reduced error, and generated cost savings.
- Designed reusable UI components and libraries for other developers to use.
- Created a fully responsive UI with reusable components suitable for all mobile devices for real-time widgets using WebSockets, Angular, Angular Material, and NGRX Store.
Technologies: Responsive Coding, User Interface (UI), Front-end, HTML5, Yarn, WebSockets, Front-end Architecture, SCSS, RxJS, Agile, JSON Web Tokens (JWT), jQuery, Gulp, Babel, SaaS, REST APIs, Git, WebStorm, Front-end Development, ECMAScript (ES6), Sass, NgRx/store, Webpack, JavaScript, TypeScript, Angular, Web Development, GitHub, API Integration, Figma to HTML, Responsive UI, HTML, REST, JSON
Experience
Appointy 9
A web-based SaaS product for scheduling classes, appointments, events, meetings, and rooms. I headed the entire front-end development, from selecting the technologies to creating the modular architecture and writing more than 90% of the front-end code. Google and Telefonica used components of this product.
Saastack
A web-based SaaS platform for bootstrapping SaaS products. It has basic, out-of-the-box features, such as accessibility, internationalization, RTL support, theming, and modularization. The hook-based architecture allows users to build and adjust their apps on the fly.
Appointy X
A web-based SaaS product for scheduling classes, appointments, events, and meetings. This is a newer version based on Saastack, written in a different stack from the ground up. I developed the architecture, built basic apps, and created many components for the team to use.
Accevate Management App
https://ibb.co/album/0m8CZnA React Native-based mobile app that I built from scratch. Features included dark mode, internationalization, multi-user login, and local state management. I also collaborated with the back-end developers to integrate APIs.
Haseed Invest
A Node.js back-end API for stock market investments. This included integration with interactive third-party brokers for the purchase and management of stocks. I added several new features such as remote log out using Redis, cron management, and OAuth 2 flow for user authentication with Saudi government services.
Toptal React Accelerator
The Toptal React Accelerator is an exclusive learning program that educates JavaScript developers in React, NextJS, Redux, and GraphQL. This is a two-month program consisting of rigorous learning exercises and hands-on activities, a stringent evaluation process, comprehensive learning assessments, and 30-40 hours of building an invoice management system. Users can track invoices, clients, and company information within this invoicing application.
GrowthDay
http://growthday.comI served as the technical lead for GrowthDay, a large-scale personal development SaaS platform. I led the architecture, development, and modernization of the web, mobile, and back-end systems across React, Next.js, React Native, Node.js, and GraphQL. I rebuilt core product flows, redesigned major UI and back-end components, and improved performance, scalability, and reliability across the entire stack.
I architected AWS infrastructure using ECS, Lambda, CloudFront, S3, RDS, DynamoDB, and CloudFormation, reducing costs while supporting significant user growth. I implemented analytics, growth, and experimentation pipelines using Mixpanel, RudderStack, Statsig, GA4, and Meta Pixel to power data-driven decisions, A/B tests, and feature rollouts. I also led the integration of Stripe and RevenueCat for subscriptions and payments.
My work included building real-time coaching and events, Growth Groups, a complete feedback system with annotation tools, Strapi-based content workflows, and an enterprise version of the platform. I established CI/CD pipelines with GitHub Actions and introduced automated testing. I collaborated closely with product, design, and executive teams to shape the roadmap and deliver high-impact features end-to-end.
I architected AWS infrastructure using ECS, Lambda, CloudFront, S3, RDS, DynamoDB, and CloudFormation, reducing costs while supporting significant user growth. I implemented analytics, growth, and experimentation pipelines using Mixpanel, RudderStack, Statsig, GA4, and Meta Pixel to power data-driven decisions, A/B tests, and feature rollouts. I also led the integration of Stripe and RevenueCat for subscriptions and payments.
My work included building real-time coaching and events, Growth Groups, a complete feedback system with annotation tools, Strapi-based content workflows, and an enterprise version of the platform. I established CI/CD pipelines with GitHub Actions and introduced automated testing. I collaborated closely with product, design, and executive teams to shape the roadmap and deliver high-impact features end-to-end.
Education
2013 - 2017
Bachelor's Degree in Civil Engineering
Maulana Azad National Institute of Technology - Bhopal, India
Certifications
JUNE 2026 - DECEMBER 2026
Claude Certified Architect
Anthropic
MAY 2022 - PRESENT
Toptal React Accelerator Graduate
Toptal, LLC
Skills
Libraries/APIs
Node.js, React, REST APIs, jQuery, React Router, Formik, Stripe, React Redux, Passport.js, OpenAI API, Claude API, Stripe Connect, WebRTC, Antd, RxJS, NgRx/store
Tools
WebStorm, Slack, Git, Webpack, Babel, Gulp, Expo, Yarn Workspaces, Google Analytics, Facebook Pixel, GitHub, Figma to HTML, Shadcn UI, Claude, Claude Code, Codex, ChatGPT, Braze, Keycloak, n8n, AI SDK, NGINX, Firebase Cloud Messaging (FCM), Miro, Claude Agent SDK
Languages
JavaScript, TypeScript, ECMAScript (ES6), GraphQL, Sass, HTML5, CSS, HTML, Python, PHP, SCSS
Frameworks
React Native, Redux, Angular, Relay, Ionic, Next.js, Material UI, Yarn, Express.js, NestJS, JSON Web Tokens (JWT), Tailwind CSS, Laravel, OAuth 2
Paradigms
Responsive Coding, REST, Responsive Web Design (RWD), Mobile Design, Mobile UI Design, UI Design, Agile, Automation
Platforms
MacOS, Mixpanel, RudderStack, Vercel, Mobile, Webflow, Amazon Web Services (AWS), RevenueCat, Kajabi, Firebase, Contentful, Docker, Netlify, Heroku
Storage
MySQL, PostgreSQL, Databases, NoSQL, JSON, Database Structure, Elasticsearch, MongoDB
Industry Expertise
Web Design
Other
SaaS, Styled-components, ESLint, Storybook, Front-end Development, Front-end Architecture, APIs, Front-end, User Interface (UI), Progressive Web Applications (PWAs), Full-stack, Web Development, User Experience (UX), Architecture, Leadership, Google Tag Manager, CAPTCHA, Statsig, GitHub Actions, Payment Gateways, Supabase, Apple Pay, API Integration, Responsive UI, Google Pay, Technical Leadership, Tailwind UI, Artificial Intelligence (AI), Reporting, Dashboards, Payments, Mobile Architecture, Agentic AI, Cloud, Generative Artificial Intelligence (GenAI), Audio, Data Structures, Security, UI Animation, Data Modeling, Scalability, Scalable Architecture, OpenAI, Webhooks, Web Content Accessibility Guidelines (WCAG), CI/CD Pipelines, CMS, WCAG 2, Figma to React, Component Libraries, Education Technology (Edtech), Agentic Coding, Cursor AI, OpenRouter, TypeORM, WebSockets, Monorepos, Analytics, Full-stack Development, Customer Relationship Management (CRM), AI Tools, Cloudflare, Large Language Models (LLMs), Anthropic, Gemini, Design Systems, AI Engineering, Apollo, Cordova, Back-end Development, Videos
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