Sandeep is available for hire
Hire SandeepSandeep Amarnath
Verified Expert in Engineering
Software Developer
Toronto, ON, Canada
Toptal member since February 6, 2026
Bio
Sandeep is a senior React Native engineer with 7+ years of experience building high-performance mobile and web applications. He's led front-end migrations, improving load times by 30%, and built production apps from scratch. At companies like OANDA, Sandeep has delivered scalable solutions serving thousands of users with React Native, React, and TypeScript.
Portfolio
Staples Canada ULC
React, Shopify, Algolia, Contentful, Shopify Storefront API...
Quartermaster
React, React Native, TypeScript, NoSQL, Zustand, Auth0, APIs, API Integration...
Oanda
React, Redux, TypeScript, Node.js, Express.js, State Machines, MongoDB...
Experience
- React Native - 7 years
- TypeScript - 7 years
- JavaScript - 7 years
- React - 7 years
- Redux - 6 years
- Node.js - 5 years
- Expo - 4 years
- Zustand - 2 years
Preferred Environment
React Native, React
The most amazing...
...solution I've built is a React Native marketplace app from scratch that now serves thousands of daily users with real-time chat and AI features.
Work Experience
Tech Lead
2026 - PRESENT
Staples Canada ULC
- Led front-end development for staples.ca within a React/Shopify architecture, managing integrations across Algolia search, Akeneo PIM, and Shopify Storefront API, serving millions of Canadian customers.
- Managed a cross-functional team of 4 developers conducting code reviews, sprint planning, and tech feasibility assessments while negotiating sprint priorities with Product Management to balance feature delivery and technical debt reduction.
- Orchestrated Bootstrap 4 to 5 migration to meet compliance requirements, establishing a comprehensive UI test suite from scratch to validate component behavior across breaking changes, ensuring zero customer-facing regressions during deployment.
- Drove technical research and vendor coordination for RichRelevance-to-data science API migration, working with external consultants and internal teams to architect a phased transition strategy while maintaining email personalization functionality.
- Resolved critical production incidents impacting revenue through systematic debugging across multi-system data flows, including a duplicate SKU issue that uncovered $40,000 in lost revenue over a 3-day period within the first two weeks of the role.
Technologies: React, Shopify, Algolia, Contentful, Shopify Storefront API, Full-stack Development, Full-stack, AI Tools, REST APIs, Git
Senior Software Developer
2024 - 2025
Quartermaster
- Led front-end migration from a React and Angular hybrid to modern React architecture, reducing page load times by 30% and improving maintainability.
- Built React Native mobile applications for homeowners and professionals from scratch, independently managing the entire mobile development lifecycle.
- Developed real-time chat features using Stream Chat, transitioning from a project-based to a single-channel model that improved user engagement.
- Created a reusable UI component library using React and Storybook, following WCAG accessibility standards to ensure design consistency.
Technologies: React, React Native, TypeScript, NoSQL, Zustand, Auth0, APIs, API Integration, Next.js, MUI CSS, Front-end, Claude Code, Cursor AI, Styled-components, Marketplaces, Full-stack, Tailwind CSS, AI Tools, NestJS, Integration, REST APIs, Authentication, Clerk, Git, Webhooks, Android, App Store, Google Play Store, Row-level Security (RLS), OAuth, Vercel, iOS
Software Engineer
2021 - 2023
Oanda
- Built a multi-step onboarding application handling 15+ country-specific regulatory requirements, reducing client drop-off rates by streamlining the form experience across different jurisdictions.
- Implemented complex state management using Redux to handle dynamic form validations, ensuring data persistence across 8-12 form steps while maintaining compliance with financial regulations.
- Collaborated with compliance and product teams to integrate real-time API validation, reducing onboarding errors by catching regulatory issues before form submission.
- Optimized application performance by implementing lazy loading and code splitting, reducing initial load time by 40% for users accessing the onboarding flow.
Technologies: React, Redux, TypeScript, Node.js, Express.js, State Machines, MongoDB, JavaScript, Auth0, APIs, API Integration, MUI CSS, Front-end, Full-stack Development, Full-stack, Amazon Web Services (AWS), OAuth 2, PostgreSQL, REST APIs, Authentication, Git, Authorization, Row-level Security (RLS), OAuth, Vercel
Consultant
2018 - 2021
FDM group
- Completed an intensive software development training program covering React, TypeScript, SQL, and professional best practices in preparation for client placement.
- Built an internal project management tool during training using React and Node.js, enabling trainers to track cohort progress and assignment submissions more efficiently.
- Created a training resource library application using React, centralizing learning materials and coding exercises for future cohorts to access and utilize.
Technologies: JavaScript, TypeScript, React, Google Sheets API, APIs, API Integration, Front-end, REST APIs, Git, OAuth, Vercel
Software Developer
2018 - 2021
Mackenzie Investments
- Developed interactive portfolio analytics dashboards using React and TypeScript, enabling financial advisors to visualize client investment performance across multiple fund categories.
- Implemented data visualization components for fund performance tracking, improving user engagement with complex financial data through intuitive charts and graphs.
- Collaborated with the compliance team to ensure all client-facing features met regulatory requirements for Canadian financial services, maintaining 100% audit compliance.
- Optimized SQL queries for portfolio data retrieval, reducing page load times by 35% for advisors accessing client account information across thousands of records.
- Built reusable UI components for displaying fund information, creating a consistent design system used across multiple internal and client-facing applications.
Technologies: React, SQL, TypeScript, JavaScript, CSS, HTML, SendGrid API, Google Sheets API, APIs, API Integration, Front-end, REST APIs, Git, Vercel
Experience
FocusSharp App
https://focussharp.app/A focus timer built for people who want clean data about where their time actually goes - without the noise.
THE STORY
I built FocusSharp because every focus app I tried had too much going on. Streaks, badges, gamification, complex setups. I wanted something that felt like a premium watch—precise, minimal, and out of the way.
The key question I kept asking: what would this look like as an Apple Watch app? That design constraint became the product philosophy. If it doesn't fit on a watch face, it's probably clutter.
FocusSharp is the web precursor to native iOS, watchOS, and macOS apps coming soon. The web app is fully functional today, and your data will sync across devices when the native apps launch.
THE STORY
I built FocusSharp because every focus app I tried had too much going on. Streaks, badges, gamification, complex setups. I wanted something that felt like a premium watch—precise, minimal, and out of the way.
The key question I kept asking: what would this look like as an Apple Watch app? That design constraint became the product philosophy. If it doesn't fit on a watch face, it's probably clutter.
FocusSharp is the web precursor to native iOS, watchOS, and macOS apps coming soon. The web app is fully functional today, and your data will sync across devices when the native apps launch.
Thinky - Daily Riddles and Logical Puzzles
https://apps.apple.com/us/app/thinky/id6779846296Thinky is an iOS riddle app built with React Native and Expo. It's a curated database of 772 riddles sourced from the best logic or puzzle YouTube channels (TED-Ed, MindYourDecisions, and Logically Yours), public domain puzzle books (Dudeney and Sam Loyd), and top Reddit communities, no generic recycled filler. Features include a Wordle-style daily challenge with streak tracking, a coin economy (earn by solving and spend on hints and reveals), AI semantic answer checking via Groq, speech-to-text input, difficulty and category filters, favorites, and offline-first local progress. v1.3 is live on the App Store (June 2026).
Home Service Marketplace App at Quartermaster
A React Native app built end-to-end for a home service marketplace, and also the service professionals' side of the app. These two apps help homeowners find the right service professionals for home-related projects, like painting, plumbing, and more.
Cash Transaction Tracker
A React Native mobile app that solves the key limitations of existing expense-splitting tools like Splitwise. We built a custom cash transaction management solution with features including real-time balance tracking, multi-currency support, and offline-first architecture. We also developed a companion landing page with a demo video to showcase functionalities and attract clients. The technologies we leveraged included React Native, Expo, MongoDB, and Node.js.
Onboarding Application at OANDA
https://auth.oanda.com/u/login?A React app I built for onboarding clients at OANDA (Forex trading platform). This app involves a multipart form and a complex state management system, as each country's onboarding pages differ. I implemented client-side validation, multi-step form navigation, and dynamic form rendering based on regulatory requirements. The application handled sensitive financial data in compliance with strict standards, integrating with OANDA's back-end APIs for real-time validation and data persistence. I worked closely with product and compliance teams to ensure the onboarding flow met all regulatory requirements across different jurisdictions.
Education
2017 - 2018
Master's Degree in Computer Networking
Dalhousie University - Halifax, Canada
Skills
Libraries/APIs
React, REST APIs, Node.js, NativeWind, SendGrid API, Google Sheets API, Shopify Storefront API, Stripe
Tools
Expo, Git, Claude Code, Auth0
Languages
TypeScript, JavaScript, HTML, CSS, SQL
Frameworks
React Native, Tailwind CSS, Next.js, MUI CSS, NestJS, OAuth 2, Redux, Material UI, Express.js
Platforms
Vercel, Amazon Web Services (AWS), Clerk, Android, iOS, Shopify, Algolia, Contentful
Storage
NoSQL, PostgreSQL, MongoDB
Other
Web Development, APIs, Front-end, Full-stack Development, AI Tools, Authentication, OAuth, Zustand, API Integration, Full-stack, Cursor AI, Styled-components, Marketplaces, Supabase, Integration, Supabase Auth, Webhooks, Authorization, App Store, Google Play Store, Row-level Security (RLS), State Machines, EAS, Push Notifications
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