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I'm James Zhang, a full stack web developer with over a decade of experience building scalable SaaS platforms, fintech systems, and mobile-first applications. I specialize in React, Next.js, Node.js, and cloud databases, and I have a proven track record of delivering MVPs and production-ready platforms under tight timelines. Recently, I delivered AI-powered analytics modules and payment-enabled financial platforms that improved reliability and reduced processing time by more than 50%. I enjoy turning complex requirements into robust architectures, optimizing databases, and shipping features that drive real business impact through collaborative, cross-functional work.…I'm James Zhang, a full stack web developer with over a decade of experience building scalable SaaS platforms, fintech systems, and mobile-first applications. I specialize in React, Next.js, Node.js, and cloud databases, and I have a proven track record of delivering MVPs and production-ready platforms under tight timelines. Recently, I delivered AI-powered analytics modules and payment-enabled financial platforms that improved reliability and reduced processing time by more than 50%. I enjoy turning complex requirements into robust architectures, optimizing databases, and shipping features that drive real business impact through collaborative, cross-functional work.

James Zhang

App Developer, Full Stack Developer, Developer, +7

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I'm James Zhang, a full stack web developer with over a decade of experience building scalable SaaS platforms, fintech systems, and mobile-first applications. I specialize in React, Next.js, Node.js, and cloud databases, and I have a proven track record of delivering MVPs and production-ready platforms under tight timelines. Recently, I delivered AI-powered analytics modules and payment-enabled financial platforms that improved reliability and reduced processing time by more than 50%. I enjoy turning complex requirements into robust architectures, optimizing databases, and shipping features that drive real business impact through collaborative, cross-functional work.…I'm James Zhang, a full stack web developer with over a decade of experience building scalable SaaS platforms, fintech systems, and mobile-first applications. I specialize in React, Next.js, Node.js, and cloud databases, and I have a proven track record of delivering MVPs and production-ready platforms under tight timelines. Recently, I delivered AI-powered analytics modules and payment-enabled financial platforms that improved reliability and reduced processing time by more than 50%. I enjoy turning complex requirements into robust architectures, optimizing databases, and shipping features that drive real business impact through collaborative, cross-functional work.

Available to hire

I’m James Zhang, a full stack web developer with over a decade of experience building scalable SaaS platforms, fintech systems, and mobile-first applications. I specialize in React, Next.js, Node.js, and cloud databases, and I have a proven track record of delivering MVPs and production-ready platforms under tight timelines.

Recently, I delivered AI-powered analytics modules and payment-enabled financial platforms that improved reliability and reduced processing time by more than 50%. I enjoy turning complex requirements into robust architectures, optimizing databases, and shipping features that drive real business impact through collaborative, cross-functional work.

Skills

Experience Level

Expert

Expert

Expert

Expert

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Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

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Expert

Intermediate

Intermediate

Intermediate

Intermediate

Language

English

Fluent

Work Experience

Lead Front-End Engineer at Startly Labs, LLC

January 1, 2022 - June 30, 2025

Joined as a founding engineer leading the entire application development process. Managed a team of three front-end engineers. Developed mobile apps for iOS (Swift) and Android (Kotlin) with cross-platform Flutter development. Built forms-heavy interfaces, optimized workflows, integrated geospatial features using Google Maps, and improved performance and memory usage. Built backend services using Node.js and MySQL, created a custom component library cutting development time by 30%, implemented API caching reducing server load by 14%, and ensured consistent theming with Styled Components and React Native Paper.

Senior Full-Stack Engineer at Collective Hub, Inc.

June 1, 2019 - December 31, 2021

Built a responsive financial services mobile app with React Native, integrating push notifications and offline support. Set up CI/CD pipelines to deploy iOS/Android apps using GitHub Actions and Fastlane. Developed backend APIs in Node.js with Express and PostgreSQL, extended GraphQL schema and resolvers, and increased test coverage to over 80% with Jest. Improved performance by reducing unnecessary re-renders by 60%. Collaborated with UX/UI designers to create a user-friendly onboarding interface.

Senior Front-End Engineer at Sweet

January 1, 2018 - May 31, 2019

Developed front-end architecture with Next.js focusing on performance, implemented lazy loading and code splitting reducing page load time by 30%. Built a React Native app with TypeScript for cross-platform functionality. Integrated GraphQL and Apollo Client improving app performance. Migrated codebase to TypeScript and refactored to modular structure. Designed reusable components and created a dynamic auction page increasing user engagement by 23%. Conducted peer code reviews to improve code quality.

Software Engineer at SOLTECH, Inc

October 1, 2013 - December 31, 2017

Contributed to web and mobile projects by developing REST/GraphQL APIs with Node.js and Java, and creating web applications from scratch.

Software Engineer at TEKsystems, Inc

April 1, 2008 - September 30, 2013

Built Windows desktop applications using C#, WinForms, and SQL Server Express for data entry and reporting tasks.

Lead Front-End Engineer at Startly Labs, LLC

January 1, 2022 - June 30, 2025

Joined as a founding engineer and entrusted with leading the entire application development process. Managed a team of three front-end engineers. Developed the mobile app using Swift for iOS and Kotlin for Android, focusing on cross-platform development using Flutter. Built forms-heavy interfaces for the mobile app, optimizing workflows and integrating geospatial features using Google Maps. Optimized application performance and memory usage in Kotlin-based mobile applications for smooth operation across devices. Built backend services using Node.js and MySQL, ensuring smooth integration with the React Native mobile app. Constructed a custom component library, contributing to a 30% reduction in development time. Implemented an API caching mechanism with React-Query, reducing server load by 14%. Used Styled Components and React Native Paper to ensure consistent theming.

Senior Full-Stack Engineer at Collective Hub, Inc.

June 1, 2019 - December 31, 2021

Built a responsive mobile app in React Native using Expo, Hermes engine, and React Navigation. Developed responsive UIs ensuring seamless experiences across mobile platforms and web applications. Integrated push notifications and offline support enabling real-time updates and offline functionality. Set up CI/CD pipelines using GitHub Actions and Fastlane for iOS/Android deployments. Developed mobile app with React Native and Redux for state management. Used GraphQL for robust back-end integrations. Led design and development of reusable React Native components. Integrated RESTful APIs for efficient data flow. Deployed apps to Apple App Store and Google Play using pipelines. Designed GraphQL schema extensions and resolvers to support personalized financial tools. Developed backend APIs in Node.js/Express with PostgreSQL via Sequelize ORM. Increased test coverage to over 80% using Jest. Reduced unnecessary renders by 60% on bookkeeping pages. Collaborated with UX/UI designers to create u

Senior Front-End Engineer at Sweet

January 1, 2018 - May 31, 2019

Developed front-end architecture using Next.js focusing on performance optimization with lazy loading and code splitting. Built React Native app focusing on performance and scalability using TypeScript. Integrated GraphQL and Apollo Client for efficient data management and enhanced user experience. Worked closely with product managers and designers to implement mobile-first experiences and responsive UI components. Migrated codebase to TypeScript for maintainability and type safety. Refactored React SPA architecture into modular feature-based folders to improve maintainability. Implemented GraphQL middleware in Next.js API layer ensuring secure data access. Integrated React Query for streamlined API data fetching and caching. Designed reusable components with strict TypeScript interfaces and CSS Modules for style encapsulation. Set up linting and formatting pipelines. Created a dynamic auction page, boosting user engagement and bids. Participated in peer code reviews to improve code qu

Software Engineer at SOLTECH, Inc

October 1, 2013 - December 31, 2017

Contributed to web and mobile projects by developing REST/GraphQL APIs using Node.js and Java and creating web applications from scratch.

Software Engineer at TEKsystems, Inc

April 1, 2008 - September 30, 2013

Built Windows desktop applications using C#, WinForms, and local SQL Server Express for data entry and reporting.

Lead Full-Stack Engineer at Startly Labs, LLC

January 1, 2022 - June 30, 2025

Joined as a founding engineer responsible for leading the entire application development process of an ERP platform. Built the application using React.js and Express.js, developed REST APIs with TypeScript and PostgreSQL, and created Node.js microservices with asynchronous queues. Improved database performance with indexing and Prisma ORM. Implemented secure authentication flows using JWT and middleware for RBAC, and hardened app security with Helmet.js and CSRF tokens. Managed a team of three engineers, established engineering standards, refactored code into custom hooks, and constructed a component library that reduced development time by 30%. Implemented API caching with React-Query, reducing server load by 14%.

Senior Full-Stack Engineer at Collective Hub, Inc.

June 1, 2019 - December 31, 2021

Rebuilt a financial/tax reporting service with NestJS reducing tax calculation time by 37%. Improved query speeds by 25% using microservices with RabbitMQ and optimized database indexing. Refactored Node.js services to use async/await patterns in TypeScript ensuring non-blocking data flow and consistent PostgreSQL transactions. Built a bookkeeping dashboard from scratch using React.js and optimized component reuse and performance in a micro-frontend architecture. Increased test coverage to over 80% with Jest and boosted mobile onboarding completion by 25% using mobile-first design. Collaborated with designers to enhance user onboarding experience.

Senior Front-End Engineer at Sweet

January 1, 2018 - May 31, 2019

Developed front-end architecture for a blockchain platform using Next.js with a focus on performance optimizations such as SSR and lazy loading, reducing page load times by 30%. Migrated the codebase to TypeScript improving maintainability and set up linting and formatting pipelines. Created a dynamic auction page which increased user engagement by 23% and bids by 15%. Participated in peer code reviews to improve code quality.

Software Engineer at SOLTECH, Inc

October 1, 2013 - December 31, 2017

Contributed to web and mobile projects developing REST/GraphQL APIs with Node.js and Java, and creating web applications from scratch.

Software Engineer at TEKsystems, Inc

April 1, 2008 - September 30, 2013

Built Windows desktop applications with C#, WinForms, and local SQL Server Express focused on data entry and reporting functionalities.

Lead Full-Stack Engineer at Startly Labs, LLC

January 1, 2022 - Present

Started as a founding engineer leading the entire application development process for Startly, an ERP platform for service companies. Built the application with React.js and Express.js, developed REST APIs using TypeScript with PostgreSQL, and created event-driven Node.js microservices. Enhanced database performance and security using Prisma ORM, JWT authentication with RBAC middleware, Helmet.js, and CSRF tokens. Managed a team of three engineers, established engineering standards, created a custom component library, and implemented API caching to reduce server load.

Senior Full-Stack Engineer at Collective Hub, Inc.

December 31, 2021 - July 31, 2025

Rebuilt financial and tax reporting services using NestJS, improving tax calculation times by 37%. Enhanced query speeds by 25% with microservices and optimized indexing. Refactored Node.js services for non-blocking data flow using async/await in TypeScript. Developed a bookkeeping dashboard with React.js and optimized performance using micro frontend architecture. Increased test coverage to over 80% with Jest and improved mobile onboarding completion by 25% through design collaboration.

Senior Front-End Engineer at Social Sweet

May 31, 2019 - July 31, 2025

Developed front-end architecture using Next.js for a blockchain-based platform delivering digital collectibles. Implemented server-side rendering and API routing to boost SEO and reduce client-side load. Improved performance with lazy loading and code splitting, cutting page load time by 30%. Migrated codebase gradually to TypeScript, set up linting and formatting pipelines, and created a dynamic auction page that increased user engagement and bids. Participated actively in peer code reviews to enhance code quality.

Software Engineer at SOLTECH, Inc

December 31, 2017 - July 31, 2025

Contributed to web and mobile projects by developing REST/GraphQL APIs with Node.js and Java, creating web applications from scratch.

Software Engineer at TEKsystems, Inc

December 31, 2013 - July 31, 2025

Developed Windows desktop applications using C#, WinForms, and SQL Server Express for data entry and reporting.

Lead Engineer at Startly Labs, LLC

July 1, 2025 - August 21, 2025

Led a team of 11 engineers to develop a multi-module SaaS platform from scratch with React, Node.js, PostgreSQL, and AWS. Designed and implemented the Time & Expense Tracking module processing 5,000+ daily transactions with secure REST APIs and role-based access control. Built Business Insights dashboards with real-time analytics and AI-driven predictive models, integrating AI forecasting pipelines to reduce project delays by 22%. Developed an AI-powered ticket classifier for automated service routing, cutting manual triage by 40%. Applied DevOps practices including Docker, Kubernetes, and GitHub Actions to streamline CI/CD and ensure reliable deployments. Maintained production systems with proactive monitoring, error tracking, and security compliance.

Senior Software Engineer at Collective Hub, Inc

December 1, 2021 - August 21, 2025

Built scalable fintech solutions for tax, bookkeeping, and expense management targeting freelancers and small businesses. Developed onboarding workflows with React and Redux, utilizing AI-driven data validation to eliminate 90% of user form errors. Re-architected financial report services into a distributed microservices model using Node.js and Kafka, improving computation speed by 37%. Optimized PostgreSQL and Redis queries, reducing response times by 42%. Automated document classification using AI-based OCR for expense tracking, reducing manual categorization by 60%. Created bookkeeping dashboards with React and Chart.js providing real-time financial insights. Collaborated closely with product managers and designers ensuring features meet UX and compliance standards.

Full-Stack Engineer at Social Sweet

May 1, 2019 - August 21, 2025

Contributed to Sweet.io, an NFT marketplace offering gifting, auctions, and gamified token experiences. Built the iOS app from scratch with Swift enabling NFT claiming, wallet integration, and transaction management. Extended the web platform with React components supporting real-time NFT auctions and gamified interactions. Optimized Ethereum smart contract integrations to improve blockchain transaction flow and minting performance. Enhanced mobile responsiveness and accessibility following WCAG guidelines. Worked in Agile sprint cycles to deliver scalable features supporting high transaction volumes.

Software Engineer at Soltech

December 1, 2017 - August 21, 2025

Delivered enterprise-grade applications in insurance, financial services, and AI-driven platforms. Designed a claims management system using ASP.NET MVC, SQL Server, and AngularJS processing over 100,000 policies. Developed real-time analytics dashboards with Python, Flask, and D3.js for dynamic KPI visualization. Integrated secure payment gateways ensuring PCI-DSS compliance. Migrated monolithic applications to microservices with REST APIs to enhance maintainability and scalability. Implemented Jenkins and Docker-based CI/CD pipelines, reducing deployment times by 50%.

Full Stack Developer at Startly Labs, LLC

August 1, 2025 - September 5, 2025

SaaS platform for service company operations; developed responsive web interfaces in React and Next.js for project planning and reporting dashboards; built secure payment and billing workflows integrating Stripe APIs; deployed microservices with Node.js and Supabase; implemented AI-powered forecasting features; optimized database schema in Postgres; containerized services using Docker and deployed on AWS ECS with CI/CD pipelines.

Software Engineer at Collective Hub, Inc

December 1, 2021 - September 5, 2025

Financial platform for freelancers and small business owners; rebuilt financial reporting services with React and Node.js; introduced microservice architecture with Firebase; integrated Stripe and PayPal gateways; developed admin dashboards for financial oversight and ticketing workflows; deployed event-driven services with AWS Lambda.

Frontend Developer at Social Sweet

May 1, 2019 - September 5, 2025

NFT platform offering gifting, auctions, and gamified experiences; built React-based mobile web app with auction and profile modules; implemented questionnaire and gamification logic for matching NFT rewards; integrated Firebase Firestore for real-time bidding and notifications; designed admin panel for NFT event management and user analytics.

Full Stack Developer at Soltech

December 1, 2017 - September 5, 2025

Software development agency delivering SaaS and enterprise solutions; built ASP.NET and AngularJS applications with SQL Server backends; developed REST APIs consumed by mobile and web clients; automated payment and invoicing flows using third-party APIs; collaborated with clients to define MVPs, creating technical proposals and project timelines.