Marcus Hsu, Developer in Seattle, WA, United States
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Marcus Hsu

Bio

Marcus is a senior staff software engineer with 12+ years of experience building scalable full-stack applications, event-driven systems, and developer platforms. He specializes in React/React Native on the front end and Go/Python on the back end, with deep experience in Kafka, Kubernetes, and distributed systems. Marcus has worked with 31+ enterprise and startup clients to design and build web and mobile apps, delivering enterprise-scale systems used by 30+ million users across 140 countries.

Portfolio

Arista Networks
React, TypeScript, Go, Python, Apache Kafka, FastAPI, Debezium, Leadership...
Yahoo (Mail Platform)
React, TypeScript, Redux, Webpack, Large-scale Projects, UI Animation...
Flint Hills Resources (Energy operations platform)
React Native, Android, iOS, TypeScript, Mobile App Development, REST APIs, Expo...

Experience

  • JavaScript - 14 years
  • Node.js - 12 years
  • React - 11 years
  • TypeScript - 7 years
  • React Native - 7 years
  • Go - 3 years
  • Python - 3 years
  • Apache Kafka - 3 years

Preferred Environment

Node.js, JavaScript, React, React Native, TypeScript, Web & Mobile Applications, Go, Python, Apache Kafka, Full-stack Development

The most amazing...

...thing I've designed is a language-agnostic Codegen system built on OpenID to automate testing scaffolding, enabling scalable multi-language development.

Work Experience

Senior Staff Software Engineer

2022 - PRESENT
Arista Networks
  • Owned front-end development of a Jira-like internal platform for EOS workflows, driving end-to-end delivery across product, UX, and engineering with rapid iteration and live production debugging.
  • Modernized legacy Angular system to React and led JavaScript to TypeScript migration, improving maintainability, reducing bugs, and increasing team productivity.
  • Built a POC replacing a manual release process, influencing roadmap investment, then owned full lifecycle from user research and UX to rollout of a scalable solution.
  • Introduced contract testing (Pact) and built CI/CD workflows across Jenkins, Kubernetes, and Cypress, driving org-wide adoption through docs and hands-on enablement.
  • Designed a language-agnostic codegen system from OpenAPI to automate testing scaffolding, enabling scalable multi-language development (TS, Python, Go).
  • Led cross-team initiative unifying six code review systems, aligning 30+ engineers, and delivering a clear roadmap over three quarters.
  • Built event-driven architecture with Go and Kafka to process 20+ event types with high reliability, resilience, and no single point of failure.
  • Delivered full-stack solution across React, Go, Python, Kafka, and Kubernetes, including CI/CD, schema changes, and production-grade testing environments.
  • Became the organization's go-to for Kafka/Debezium, creating runbooks and supporting adoption across teams.
  • Led migration of 2+ million production records with staged rollout and strong data integrity safeguards.
Technologies: React, TypeScript, Go, Python, Apache Kafka, FastAPI, Debezium, Leadership, Apache ZooKeeper, Apache Avro, Contract Testing, Argo CD, Spinnaker, Helm, Kubernetes, Jenkins Pipeline, Zuul, Cypress, Code Generators, MySQL, Redux, Gerrit, Perforce, RESTful Microservices, REST APIs, Distributed Systems, Web Architecture, Web App Deployment, Webpack, Web Performance Optimization (WPO), OAuth 2, Full-stack Development, Jest, JavaScript, User Interface (UI), User Experience (UX), Docker, Unit Testing, E2E Testing, Responsive UI, Monorepos, Full-stack

Senior Front-end Software Engineer

2021 - 2023
Yahoo (Mail Platform)
  • Built Yahoo Mail’s sitewide animation framework from scratch, turning a UX initiative into an org-wide platform that reduced integration to a few lines of code, enabled rapid iteration, and drove adoption across multiple product teams.
  • Rebuilt Yahoo Mail’s revenue attribution across commerce surfaces, resolving affiliate tracking and redirect integrity issues so monetization data became accurate, reliable, and trusted for revenue reporting and decision-making.
  • Owned high-impact Yahoo Mail features (Tidy Inbox, Offers Preview, wishlist onboarding) end-to-end, driving cross-functional execution with product and UX across experimentation, instrumentation, launch, and iterative improvements.
  • Improved Yahoo Mail’s codebase by overhauling integration testing, significantly expanding coverage, and modernizing high-traffic workflows to increase system reliability, reduce regressions, and improve developer velocity.
Technologies: React, TypeScript, Redux, Webpack, Large-scale Projects, UI Animation, Web Performance Optimization (WPO), E2E Testing, App Themes, Internationalization, Localization, Web Accessibility, Instrumentation, Web App Development, Grunt, Monorepos, Cypress, Responsive UI, Front-end, Single-page Applications (SPAs), Agile Software Development, Web Security

Senior React Native Engineer (Sole Developer)

2022 - 2022
Flint Hills Resources (Energy operations platform)
  • Acted as sole engineer responsible for designing and delivering a cross-platform mobile app (iOS and Android) from product scoping and requirements gathering through implementation, testing, and production release.
  • Built and shipped a React Native app from scratch, handling manual iOS and Android build, signing, and release processes, including provisioning profiles, certificates, keystores, and store compliance to publish on App Store and Google Play Store.
  • Implemented push notifications across iOS and Android, configuring APNs and Firebase Cloud Messaging (FCM), handling certificates, keys, and environment setup, and resolving platform-specific differences to ensure reliable delivery.
Technologies: React Native, Android, iOS, TypeScript, Mobile App Development, REST APIs, Expo, Responsive UI, Front-end, Agile Software Development, Geolocation Detection, Mobile Development

Lead Software Engineer

2021 - 2022
Lessen (PropTech platform)
  • Led a newly-found design system team to spearhead its technical direction and provided consultation for several application teams.
  • Assessed the current codebase and devised strategies to incorporate the new design system into the existing apps.
  • Developed a centralized reusable component library from scratch, providing a set of standards to guide its usage. It increased application team productivity by enabling them to focus on business logic without building their own components.
  • Drove the adoption of the centralized reusable component library to be consumed by several React/React Native applications. It involved countless conflict resolutions, migrations, testing, and bug fixes before apps was released back to production.
  • Pioneered a way to build and run the React Native components' Storybook on iOS and Android devices and any web browser, as there was no existing solution. It enabled the components to be built once and used everywhere.
  • Set up a comprehensive unit test framework to test most kinds of user interactions on mobile devices and stimulate a native mobile environment where the framework would run. It was built with Jest, a testing library, and several others.
  • Created a design tokens build system from scratch to allow developers to style once and consume it on any platform. It became a single place to create or edit reusable style guides and assets, ensuring consistent styles across different apps.
  • Built a library to handle the responsiveness of mobile devices since there is no out-of-the-box solution in React Native to set the breakpoints like media queries on the web.
Technologies: React, React Native, Amazon Web Services (AWS), Styled-components, Material UI, React Native for Web, React Native Bridge, TypeScript, Mobile App Development, User Interface (UI), User Experience (UX), Agile Software Development, iOS, Android, Front-end, AWS CodePipeline, Webpack, Unit Testing, Jest, Technical Consulting, Web Consulting, App Development, Web & Mobile Applications, Figma, Linux, Cross-platform, Cross-platform Testing, Mobile UI, Responsive UI, Cross-platform App Development, Mobile, Monorepos, Web App Development, Web Accessibility, Single-page Applications (SPAs), Leadership, Instrumentation, Mobile Development

Staff Software Engineer

2020 - 2022
Smartsheet
  • Led modernization of a 2 million-line legacy JavaScript monorepo to a React and TypeScript SPA, defining architecture and incremental migration strategy without disrupting production.
  • Designed and executed repo decomposition into a multi-repo structure across teams, enabling scalable ownership and parallel development.
  • Built a universal integration pattern across business domains, supporting flexible and extensible data models for long-term scalability.
  • Led and mentored five engineers to rebuild a core product, introducing abstraction layers to decouple legacy APIs and quadruple development speed.
Technologies: React, TypeScript, D3.js, Java, Monorepos, Web Performance Optimization (WPO), Web Accessibility, Front-end, SCSS, Single-page Applications (SPAs), Agile Software Development, Leadership, Instrumentation

Lead Software Engineer

2021 - 2021
Stealth Luxury Real Estate Bidding Platform
  • Led a team of front- and back-end developers to spearhead the technical direction for the luxury bidding platform's minimum viable product.
  • Cooperated constantly with the PM and UX designer to make high-level architectural decisions and led design meetings, making most of the final technical decisions.
  • Performed hands-on coding daily to accomplish the client's urgent requests and critical bug fixes, and guided each junior developer to ensure the team met every sprint deadline.
  • Mentored junior developers regarding their code and approach to solving problems.
  • Reviewed every pull request in great detail before merging into the codebase to ensure the highest code quality at all times.
  • Engaged in solely maintaining the codebase after product launch, as I deeply understood how each piece of code functions for 90% of the entire codebase.
  • Accomplished several critical bug fixes, UX improvements, and new large features.
Technologies: React, Redux, User Experience (UX), User Interface (UI), SCSS, TypeScript, Formik, Agile Software Development, Front-end, RESTful Microservices, Webpack, Single-page Applications (SPAs), Unit Testing, App Development, Figma, REST APIs, Responsive UI, Jest, Full-stack Development, Web App Development, Web Performance Optimization (WPO), React Native, Leadership, Full-stack

Senior React Native and React Engineer

2021 - 2021
Arizona State University (Blockchain Identity Platform)
  • Built Android and iOS apps to manage self-sovereign identity using blockchain technology. Used complex native modules to connect to each user's wallet on the blockchain; was built with React Native, TypeScript, D3.js, Hyperledger Aries, and Indy SDK.
  • Developed an admin console—solely from scratch to product launch—to manage identities and credentials on the blockchain. It has complex charts, graphs, and animations for data visualization and is built with React, TypeScript, and Material UI.
  • Architected and implemented the admin console application's internationalization and localization features to make it available to all the supported countries.
Technologies: React, React Native, D3.js, Formik, Redux, OAuth 2, Cross-platform, Cross-platform App Development, React Native Bridge, Jest, User Experience (UX), User Interface (UI), SCSS, TypeScript, Styled-components, Material UI, Mobile App Development, Agile Software Development, iOS, Android, Front-end, Webpack, Single-page Applications (SPAs), App Development, Figma, Linux, Web & Mobile Applications, Mobile UI, Mobile, Responsive UI, Web App Development, Large-scale Projects, Mobile Development

Senior Full-stack Software Engineer

2021 - 2021
SnapCare (Healthcare workforce marketplace)
  • Engaged as the main contributor to Android mobile apps, impacting 350,000+ nurses by enabling them to log their times easily. It involved complex photo-taking, scanning, and identity verification, and was built with React Native and TypeScript.
  • Completed several painful migrations of native modules to make an existing sophisticated Android app cross-platform so it could work and be developed on iOS and Android in a single codebase.
  • Drove the front- and back-end development of real-time geolocation tracking. It involved background location tracking and geofencing, with battery-conscious motion-detection intelligence for iOS and Android using React Native and the Google Maps API.
  • Set up the complex build, deployment, beta testing, release, and code-signing processes for the App Store and Google Play Store across multiple environment configurations.
Technologies: Redux, React Native, Cross-platform, Cross-platform App Development, React Native Bridge, User Experience (UX), User Interface (UI), TypeScript, Styled-components, Material UI, Mobile App Development, Agile Software Development, iOS, Android, Front-end, Webpack, Unit Testing, App Development, Figma, Linux, Mobile UI, Mobile, Responsive UI, Jest, Full-stack Development, Geolocation Detection, Large-scale Projects, Mobile Development, Full-stack

Senior React Native & React Developer

2020 - 2021
Anthem (AI-driven Healthcare Platform)
  • Used React Native, React Native for Web, and TypeScript to build an iPad application to connect patients, doctors, and health plans seamlessly. It later expanded its capabilities to include cross-platform support, including web and Android tablets.
  • Developed solely and from scratch to product launch a healthcare app related to PIP diabetes, which impacted 800,000+ users. It was built with React and TypeScript.
  • Implemented a proof of concept to experiment with different trending technologies and fancy user experiences, such as a flowchart, to spearhead the next generation of healthcare software.
  • Built several other healthcare cross-platform applications to enable data-driven insights for patients, doctors, and administrators, leveraging artificial intelligence and machine learning technology.
Technologies: Amazon Web Services (AWS), Amazon Cognito, SCSS, React, React Native, TypeScript, Redux, Styled-components, Material UI, Mobile App Development, User Interface (UI), User Experience (UX), Agile Software Development, iOS, Android, Front-end, GraphDB, Docker, Amazon S3 (AWS S3), RESTful Microservices, Webpack, Single-page Applications (SPAs), Unit Testing, App Development, Web App Development, Figma, Web & Mobile Applications, Linux, Cross-platform, Mobile UI, REST APIs, Mobile, Responsive UI, OAuth 2, React Native for Web, React Native Bridge, Cross-platform App Development, Jest, Monorepos, Large-scale Projects, Containers, Instrumentation, Mobile Development

Senior Software Engineer

2015 - 2020
ADP
  • Led front-end development of new user onboarding and account setup workflows across web and mobile for 30+ million users worldwide, and was later promoted to tech lead for a 10+ engineer team building a new identity control center for 20,000+ users.
  • Led internationalization for client-critical ADP web experiences, making the platform available worldwide across 140+ countries.
  • Named inventor on three granted patents for proprietary authentication, authorization, and MFA architecture and frameworks across web and mobile applications, adopted across ADP's core products supporting payroll for 15,000+ companies worldwide.
  • Delivered enterprise identity solutions in ADP's fast-paced, highly experimental, R&D-oriented innovation lab, leveraging cutting-edge open-source technologies in a security-critical domain where ADP ranked number one in Security 500.
  • Served as the main POC for client-critical identity workflows, presenting progress and research to leadership and driving alignment on architecture decisions.
  • Mentored 10+ engineers across levels and authored a front-end best-practices playbook, raising code quality and engineering standards.
  • Architected a company-wide E2E testing framework and automated Jenkins pipelines, improving release quality, cross-browser coverage, and CI/CD reliability.
Technologies: Amazon Web Services (AWS), SCSS, JavaScript, MongoDB, MySQL, Node.js, Redux, React Native, React, Mobile App Development, Jest, NoSQL, Web App Development, User Interface (UI), User Experience (UX), Agile Software Development, iOS, Android, Front-end, GraphDB, Docker, Amazon S3 (AWS S3), RESTful Microservices, Webpack, Jenkins Pipeline, Single-page Applications (SPAs), Unit Testing, Leadership, App Development, TypeScript, Web Architecture, Web App Deployment, Technical Leadership, Figma, Material UI, Styled-components, Web & Mobile Applications, Linux, Cross-platform, Mobile UI, REST APIs, Mobile, Containers, Minimum Viable Product (MVP), Responsive UI, Sequelize, Cross-platform App Development, React Native Bridge, Monorepos, Large-scale Projects, Internationalization, Localization, Web Accessibility, Instrumentation, Web Performance Optimization (WPO), Full-stack Development, Cross-platform Testing, Cypress, Geolocation Detection, Full-stack, Mobile Development, Web Security

Full-stack Web Developer

2014 - 2015
Acupay
  • Developed solely and from scratch to launch a global asset management services web app with a monthly value of $500,000. It was built with AngularJS, Node.js, Express.js and Jade, Microsoft SQL Server, Grunt, and multi-factor authentication (MFA).
  • Built by myself and from scratch to launch a European tax-processing-services web app with a monthly value of $100,000. It was built with Angular, Node.js, Hapi.js, Handlebar.js, and Microsoft SQL Server.
  • Implemented a centralized mailing server to manage all internal email in a secure channel and provide an admin dashboard with real-time mailing status updates and stats charts. It was built with React, Flux, WebSockets, D3.js, and Grunt.
Technologies: Grunt, D3.js, WebSockets, Node.js, Microsoft SQL Server, JavaScript, React, App Development, Front-end, Web App Development, Single-page Applications (SPAs), Redux, Figma, Web & Mobile Applications, Linux, REST APIs, Minimum Viable Product (MVP), Responsive UI, Sequelize, User Interface (UI), Full-stack Development, MySQL, Instrumentation, Full-stack

Teaching Assistant

2014 - 2014
Columbia University
  • Assisted the professor in supervising over 50 students concerning their big data programming projects using Hadoop 2, Pig, Mahout, GraphDB, Hive, HBase, and Oozie.
  • Offered support to guide and debug all course-related resources, assignments, and projects for over 100 students every week.
  • Hosted teaching assistant sessions for live demos to demonstrate how to build, run, and develop Pig, Hive, HBase, Oozie, Mahout, and GraphDB in a Hadoop 2 ecosystem and how to apply them to a real-world problem.
Technologies: GraphDB, Hadoop, Amazon Web Services (AWS), Amazon S3 (AWS S3), Leadership, Technical Leadership, Web & Mobile Applications, Linux, REST APIs, Mobile, Web App Development, App Development, OAuth 2, User Interface (UI)

Experience

Arthur Murray Official (iOS and Android)

https://www.arthurmurrayofficial.com/
The number one tool for competitive ballroom dancers.

It is built for the world's largest ballroom dance studio franchise. It uses React Native for the front end and Node.js and MySQL for back-end big data processing.

I am not working directly for Arthur Murray but for FHConcept, which works directly with Arthur Murray.

Pinto (iOS and Android)

https://monkey-tree.vercel.app/app_pinto
Pinto is the number one digitization platform that provides an efficient and smart way to record, upload, and track the ingredients of each product on the shelf for the largest retailers like Kroger. It's built with React Native and GraphQL for the front end, along with an integration with the existing back end.

It's available for download in the App Store (Apple.co/2Qz6VEj) and Play Store (Bit.ly/3ap7OGK).

Pacesetter (iOS)

https://monkey-tree.vercel.app/app_pacesetter
A fitness application that trains athletes to control their pace in a marathon in real-time. It's built with React Native for the front end as well as geolocation, motion tracking, and iTunes integration; Firebase for back-end data storage. It's currently in beta testing and will be available in the App Store very soon.

Get Apollo (iOS and Android)

https://monkey-tree.vercel.app/app_get-apollo
The go-to app for real-time party information of your favorite clubs and bars at your fingertips. It's built with React Native for the front end; Firebase for back-end storage, OAuth authentication, and app analytics. It's available for download in the App Store (Apple.co/2Lh7oq3) and Play Store (Bit.ly/2WhuujG).

Circlus Connect (iOS)

https://monkey-tree.vercel.app/app_circlus-connect
A platform that uses influencers' voices to help locals find delicious restaurant deals. It's built with React Native for the front end and Node.js, MongoDB, and Stripe API for back-end payment processing. It's available for download in the App Store (Aapple.co/2VGkTC3).

Local Detour (iOS)

https://monkey-tree.vercel.app/app_local-detour
A location-based service helps people to uncover off-the-beaten-path events. It's built with React Native for the front end; Firebase for back-end data storage and OAuth authentication. It's available for download in the App Store (Apple.co/2VEdHX6).

Future Plans (iOS)

https://monkey-tree.vercel.app/app_future-plans
A life-and-financial planning platform to get your future covered. It's built with React Native and Expo for front-end rapid prototyping. It's currently in beta testing and will be available in the App Store very soon.

Wonda Shop (iOS and Android)

https://monkey-tree.vercel.app/app_wonda
A leading eCommerce platform to shop for food, cosmetics, apparel, electronics, and home goods.

It's built with React Native and Expo for front-end rapid prototyping. It's currently in beta testing and will be available in the App Store and Play Store very soon.

Goti (iOS and Android)

https://monkey-tree.vercel.app/app_goti
The 1st social media and marketplace platform customized exclusively for women. It's built with React Native and Expo for front-end rapid prototyping. It's currently in beta testing and will be available in the App Store and Play Store very soon.

Lifion by ADP (Web)

I contributed to the build of an industry-leading payroll and HR management platform that has impacted over 30 million users in around 140 countries. It's built with React, Redux, and several proprietary custom-built components.

Play Nice (Web)

I contributed to the development of a platform to eliminate cyberbullying. It's built with React for the front end and Node.js, MongoDB, Stripe API, Twilio API, and Gmail API for the back end. Feel free to reach out for more details.

Taiwan Society for Risk Analysis (Web)

I contributed to the development of an international academic platform. It's built with React for the front end and Node.js, MongoDB, and Firebase for back-end data storage. Feel free to reach out for more details about the project.

Sugarpost (Web)

I contributed to the development of a construction management platform. It's built with Angular for the front end and Node.js and MongoDB for back-end big data processing. Feel free to reach out for more details about the project.

CMTech (Web)

I contributed to the development of this construction management platform. It's built with Angular for the front end and Node.js and MongoDB for back-end big data processing. Feel free to reach out for more details about this project.

Source Code for a React Native App

https://github.com/vibe-checked/get-apollo
I architected and built the entire front end for a React Native mobile app that I built, including reusable components, scalable screen organization, and Redux-based state management. This codebase powers the Get Apollo app, currently available on the App Store (Apple.co/2Lh7oq3) and launching soon on the Play Store (Getapollo.in).

Source Code for a React App (Full-stack)

https://github.com/kiddkevin00/top-times
I architected the code structure for a React web app that I built, and its back-end server. It is built with React, Redux, Sass, and Jest for the front end and Node.js, MongoDB, PostgreSQL, Mocha, and JWT for the back end.

Education

2013 - 2014

Master's Degree in Electrical Engineering and Computer Science

Columbia University - New York, NY, USA

2009 - 2012

Bachelor of Science Degree in Engineering Science and Computer Science

National Taiwan University - Taipei, Taiwan

Skills

Libraries/APIs

React, Node.js, Jenkins Pipeline, REST APIs, Formik, React Native for Web, D3.js, Stripe API, Stripe Connect API

Tools

Webpack, Expo, Mocha, Sequelize, Figma, Amazon Cognito, Grunt, Apache ZooKeeper, Apache Avro, Helm, Zuul, Gerrit, Perforce

Languages

SCSS, JavaScript, TypeScript, Go, Python, GraphQL, Java

Frameworks

React Native, OAuth 2, Jest, Redux, JSON Web Tokens (JWT), Material UI, Cypress, Hadoop

Paradigms

Agile Software Development, Unit Testing, App Development, Web Architecture, Cross-platform, Web Performance Optimization (WPO), E2E Testing, Mobile Development

Platforms

Firebase, Docker, Mobile, Linux, Apache Kafka, Debezium, iOS, Android, Amazon Web Services (AWS), Spinnaker, Kubernetes

Storage

MongoDB, MySQL, NoSQL, Microsoft SQL Server, PostgreSQL, Amazon S3 (AWS S3)

Other

RESTful Microservices, Mobile App Development, Web App Deployment, Front-end, User Experience (UX), User Interface (UI), NativeBase, Single-page Applications (SPAs), Web App Development, Responsive UI, Minimum Viable Product (MVP), Containers, Consulting, Technical Consulting, Web Consulting, CTO, Mobile UI, Styled-components, Web & Mobile Applications, React Native Bridge, Cross-platform Testing, Cross-platform App Development, Monorepos, Full-stack Development, Large-scale Projects, UI Animation, Internationalization, Localization, Web Accessibility, Instrumentation, Full-stack, Mobile Payments, Stripe Payments, Leadership, Geolocation, Airtable, Technical Leadership, AWS CodePipeline, Web Security, App Themes, FastAPI, WebSockets, GraphDB, Geolocation Detection, Big Data, Contract Testing, Argo CD, Code Generators, Distributed Systems

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