Sean Zeng, Developer in Auckland, New Zealand
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Sean Zeng

Verified Expert  in Engineering

Full-stack Developer

Auckland, New Zealand
Toptal Member Since
July 16, 2020

Sean is a software architect from New Zealand specializing in full-stack development with a strong focus on usability, security, and simplicity. He's built business applications, streamlined development with DevOps pipelines, and delivered latency-sensitive architecture. With a passion for software, he excels at providing reliable management and great ideas. Sean enjoys working with brilliant, humble people who aren't afraid to tackle challenges and take the initiative to create excellence.


The University of Auckland
Full-stack Development, Lecturing, Team Mentoring, Code Auditing, Docker...
React Native, WebAuthn, Web Extensions, Cryptography, Ethereum, Parity Polkadot...
Node.js, APIs, TypeScript, JavaScript, CSS, Linux, Full-stack, Authentication...




Preferred Environment

WebStorm, GitHub, PyCharm, React, Azure, Amazon Web Services (AWS), Mobile Apps, Jupyter Notebook, Cloudflare, Linux

The most amazing...

...PWA React game I've built was a modular Node.js game server over Socket.IO with leaderboards, real-time chat, email, Stripe payments, and latency compensation.

Work Experience

Professional Teaching Fellow (Lecturer)

2023 - 2024
The University of Auckland
  • Lectured over 200 postgraduate information technology students on a broad range of topics, including Java Object-Oriented Programming, full-stack development, and database design. Achieved a cumulative average of 95% in feedback evaluations.
  • Reviewed over 1000 independent codebases, grading code quality and providing feedback to authors where needed. Codebases range from five-person team repositories to small OOP code bases. Developed scripting tools to help automate manual processes.
  • Worked with the team on adapting AI use to best prepare aspiring developers to be effective in the workplace. Learned to differentiate subtle fingerprints of AI-generated code and adapted mitigation strategies to help improve quality and learning.
  • Mentored 10 different teams of 5 full-time developers simultaneously in an Agile development environment. Developed strategies using Git access control to simplify the management of formal PR processes, reducing the occurrence of workflow regressions.
Technologies: Full-stack Development, Lecturing, Team Mentoring, Code Auditing, Docker, Svelte, React, Databases, Node.js, Java, Object-oriented Programming (OOP)

Full-stack React Native Developer

2021 - 2022
  • Designed and implemented public key challenge server authentication for a crypto-wallet Chrome browser extension based on WebAuthn standards.
  • Developed a cost-effective, secure solution for tracking view counts on a marketplace platform. Utilized Google Cloud GA4 Analytics API for accurate report generation on our servers.
  • Animated front-end UI elements with compatibility across React Native web, iOS, and Android deployments.
  • Helped implement CI deployment strategies to speed up our Agile development cycles. Automated deployments to AWS, specifically CloudFront, S3, EBS, and Amplify.
Technologies: React Native, WebAuthn, Web Extensions, Cryptography, Ethereum, Parity Polkadot, React Native for Web, iOS, Android, Google Analytics, Google Cloud, AWS Amplify, Amazon CloudFront CDN, Amazon S3 (AWS S3), Amazon EBS, CircleCI, HTML, Blockchain & Cryptocurrency, Cryptocurrency, Redis, SQL, APIs, Web3.js, TypeScript, PostgreSQL, JavaScript, CSS, Security, Linux, Full-stack, Amazon Web Services (AWS), Amazon EC2, AWS Lambda, Google Tag Manager, Google Analytics 4, Authentication, Jest, MEAN Stack, MERN Stack, Front-end, Figma, Cryptocurrency Wallets, MetaMask, Integration, Discord, Search Engine Optimization (SEO), Scripting, Automation Scripting, Reports, Metrics, CI/CD Pipelines

Lead Full-stack React Developer

2021 - 2021
  • Designed cost-effective architecture for a feature-rich, monetized, multiplayer variant chess game, X-Chess Project.
  • Oversaw and mentored developers to deliver features with minimal technical debt and optimal workplace culture.
  • Worked directly with the client in an agile development environment, achieving optimal task prioritization, time estimation, and feature prioritization.
Technologies: Node.js, APIs, TypeScript, JavaScript, CSS, Linux, Full-stack, Authentication, Bots, Jest, MEAN Stack, MERN Stack, Leadership, Front-end, Redux, Integration, Discord, Search Engine Optimization (SEO), Scripting, Automation Scripting, Dashboards, Reports, CI/CD Pipelines

Software Engineering Intern

2019 - 2020
  • Completed data visualization of application and customer information using D3.js.
  • Offered quote estimations via Restful API to a front-end Material UI and React interface protected by Azure Active Directory authentication.
  • Oversaw the automatic deployment of new changes to both front-end and back-end servers using Azure DevOps, including automated SQL server migrations.
  • Completed unit testing in .NET C# to validate proprietary algorithms.
  • Oversaw team-based GitHub management, including pull requests, code reviews, and merging complex changes in a React front end.
Technologies: NPM, Migration, C#, Azure Active Directory, Azure SQL, SendGrid, MySQL, REST APIs, GitHub, Material UI, Unit Testing, C#.NET, Azure DevOps, D3.js, React, .NET Core, SQL, APIs, TypeScript, PostgreSQL, JavaScript, CSS, Linux, Full-stack, Authentication, MEAN Stack, MERN Stack, Leadership, Front-end, API Integration, Integration, Scripting, Dashboards, Reports, CI/CD Pipelines

Unity and Node.js Server Developer

2016 - 2019
Mediahive, LTD.
  • Developed a manageable, latency-sensitive architecture to relay game data in a performant, economical manner using Socket.IO.
  • Orchestrated an Azure DevOps CI pipeline with the test, staging, and production steps to streamline complex deployment variables and catch mistakes early.
  • Developed a performant user data update protocol using NoSQL and MongoDB. Rapid game state changes on the client are first aggregated and then sent to the server in short bursts to optimize the database and server workload.
  • Integrated third-party APIs to facilitate secure monetary transactions.
Technologies: Firebase, WebStorm, TypeScript 3, Unity2D, MongoDB, REST APIs, JavaScript, Node.js, Azure DevOps, Express.js, Unit, Mocha, Azure, DevOps, Socket.IO, Android, Cryptocurrency, Docker, APIs, TypeScript, CSS, Security, Linux, Data Engineering, Azure Functions, Bots, Jest, LAMP, Front-end, Scraping, Integration, Discord, Scripting, Google Sheets, Reports, CI/CD Pipelines

A Unity iOS/Android multiplayer game. Developed and integrated Node.js server relay architecture for low-cost enablement of real-time multiplayer activities. Utilized Firebase Realtime storage for game data storage and authentication.

X-Chess License Code Package

A CLI application that allows traceable generation and validation of license codes, cryptographically verifiable without the need to contact a server. It also lets physical product items contain rewards for virtual items in-game.


A multiplayer chess game built in React with monetization. Features in-game item store, Shopify purchases, WebAssembly chess engine, license code award system, game history, transaction history, admin control panel, and in-game chat. Low-cost architecture for minimal upkeep and hosting costs.
2021 - 2021

Postgraduate Diploma in Computer Science

The University of Auckland - Auckland

2016 - 2019

Bachelor's Degree in Computer Science

The University of Auckland - Auckland, New Zealand


Microsoft Certified: Azure Fundamentals



Node.js, React, REST APIs, React Redux, Socket.IO, D3.js, React Native for Web, AWS Amplify, Web3.js, Puppeteer


GitHub, Google Sheets, NGINX, SendGrid, NPM, Google Analytics, MongoDB Atlas, Azure App Service, Docker Compose, Auth0, Microsoft Excel, MetaMask, Jira, Let's Encrypt, IntelliJ IDEA, WebStorm, JetBrains Rider, PyCharm, Mocha, Amazon CloudFront CDN, Amazon EBS, CircleCI, Figma


Python 3, JavaScript, Python, TypeScript, SQL, TypeScript 3, CSS, C++17, Java 11, C#.NET, C#, HTML, HTML5, Java 8, Java, PHP, Go, GraphQL, Excel VBA


Web Architecture, Unit Testing, RESTful Development, Azure DevOps, Web Application Architecture, MEAN Stack, Search Engine Optimization (SEO), Data Science, Object-oriented Programming (OOP), Dynamic Programming, DevOps, Management, Agile


Windows, Azure, Docker, Amazon Web Services (AWS), Linux, Anaconda, Magento 2, WordPress, Firebase, MacOS, Android, LAMP, Ethereum, iOS, Shopify, Blockchain, Raspberry Pi, Amazon EC2, AWS Lambda, Azure Functions, DigitalOcean, Jupyter Notebook


MongoDB, PostgreSQL, Redis, Docker Cloud, MySQL, Azure SQL, Azure Active Directory, Google Cloud, Amazon S3 (AWS S3), Databases


Express.js, Material UI, .NET Core, Jest, Redux, Django, Unity2D, .NET 3, .NET, Bootstrap, .NET 4, Unity, React Native, Parity Polkadot, Next.js, Tailwind CSS, Scrapy, Selenium, NestJS, Svelte


Web Scraping, Gaming, Access Control, APIs, Full-stack, Authentication, MERN Stack, Data Scraping, Scraping, API Integration, Discord, Scripting, Full-stack Development, SSL Certificates, CI/CD Pipelines, Stakeholder Management, IT Security, MikroTik, Ubuntu Server, Data Visualization, WebAuthn, eCommerce, IoT Security, Blockchain & Cryptocurrency, Security, Data Engineering, FIDO2, Bots, CAPTCHA, Front-end, Integration, Discord Bots, Automation Scripting, Dashboards, Reports, Algorithms, Machine Learning, Computational Biology, TCP/IP, GitKraken, Cryptocurrency, Unit, Web Extensions, Cryptography, Cloud, Private NPM Modules, WebAssembly, Live Chat, Data Privacy, Chrome Extensions, Distributed Systems, Web Security, Software & Hardware Maintenance, Software Development Management, Mobile Apps, Google Tag Manager, Google Analytics 4, Leadership, Cryptocurrency Wallets, Migration, Cloudflare, Metrics, Lecturing, Team Mentoring, Code Auditing, AWS DevOps

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