Shavarsh S.
JavaScript Developer | Browser Extensions | Front-End | Mobile Apps
I am a TOP RATED PLUS Senior Full Stack Engineer with a strong focus on browser technologies, Chrome Extension - Plugin development, and scalable web applications. I have completed 22,000+ hours on Upwork with consistent 5-star reviews. My core expertise is building and maintaining Chrome, Edge, Firefox, and Safari extensions — including full lifecycle development from architecture to store submission. This includes Manifest V2 → V3 migrations, content scripts, background/service workers, messaging systems, DOM manipulation, automation flows, and integrations with tools like ChatGPT and other AI APIs. I also work on modifying and stabilizing existing extensions, improving performance, and ensuring compliance with browser store policies. From a full stack perspective, I design and build end-to-end systems using modern JavaScript and web technologies: * Frontend: React, Next.js, Vue.js, TypeScript, state management, SPA architecture * Backend: Node.js (Express/NestJS), REST APIs, GraphQL, authentication, webhooks * Data: PostgreSQL, MongoDB, Redis, data modeling and optimization * Realtime: WebSockets, event-driven systems * Integrations: third-party APIs, browser APIs, scraping/automation flows * DevOps: CI/CD, Docker, cloud deployments (AWS/GCP), monitoring I have built complex platforms across multiple domains, including marketplaces, SaaS products, CMS, CRM systems, browser automation tools, and internal business platforms. Many of these involve multi-user systems, dashboards, analytics, and high-performance backend logic. I also have experience with UI/UX implementation, product thinking, requirement specification, and working with partially generated or AI-assisted codebases — refactoring them into clean, production-ready systems. My focus is on building reliable, secure, and scalable solutions with strong attention to performance, maintainability, and real-world usability. Happy to discuss your project or jump on a call to go through the technical details. Profile updated: 03 November 2026
Earnings and projects
Last 6 months ÷ 6
Last 6 months: $29k
Billed in all: $739,799$740k
$15k in the last 6 months
Across 3 contracts
Across 39 contracts
Earnings, last 30 days
Skill rankings: Top 1% in HTML5
Ranked by MRR among everyone on Upwork with the skill.
- #8Browser Extension203 freelancers · 🇦🇲 #1Top 4%🇦🇲#1 of 3
- #22Google Chrome Extension660 freelancers · 🇦🇲 #1Top 3%🇦🇲#1 of 8
- #96iOS3,908 freelancers · 🇦🇲 #4Top 2%🇦🇲#4 of 39
- #105Android4,975 freelancers · 🇦🇲 #3Top 2%🇦🇲#3 of 38
- #163Android App Development6,395 freelancers · 🇦🇲 #3Top 3%🇦🇲#3 of 34
- #178iOS Development6,533 freelancers · 🇦🇲 #4Top 3%🇦🇲#4 of 46
- #207API7,943 freelancers · 🇦🇲 #6Top 3%🇦🇲#6 of 86
- #216HTML514,581 freelancers · 🇦🇲 #5Top 1%🇦🇲#5 of 177