Erik is available for hire
Hire ErikErik Sytnyk
Verified Expert in Engineering
JavaScript Developer
Phuket, Thailand
Toptal member since February 2, 2017
Bio
Erik is a senior full-stack developer whose work encompasses enterprise back-end systems and projects for small tech startups. He is passionate about building scalable and well-structured software. Erik's most recent projects involved creating complex front-end systems in React from scratch.
Portfolio
Fleet AI INC
TypeScript, Python, SQLite, Node.js, React, Svelte, Full-stack Development...
Woven Alpha - Arene OS (Dan Hebbard)
React, Node.js, JavaScript, TypeScript, Storybook, Cypress, Redux, Snowflake
Optimal Ship
React, TypeScript, Next.js, React Redux, HTML5, Tailwind CSS...
Experience
- JavaScript - 10 years
- React - 10 years
- PostgreSQL - 7 years
- Node.js - 7 years
- MongoDB - 7 years
- TypeScript - 7 years
- Next.js - 5 years
- OpenAI API - 1 year
Work Experience
Full-stack Developer
2025 - 2025
Fleet AI INC
- Developed a few popular commodity/tools website clones to train AI agents (AI-based SaaS startup).
- Created an efficient AI development process for CloneAI/mock functionality prototype building.
- Delivered an end-to-end site clone working prototype in around 1+ week per site on average.
Technologies: TypeScript, Python, SQLite, Node.js, React, Svelte, Full-stack Development, Artificial Intelligence (AI), Claude, Cursor AI
Full-stack Developer
2023 - 2024
Woven Alpha - Arene OS (Dan Hebbard)
- Developed a new platform. Built a video annotation system from scratch, replacing Toyota's legacy solution.
- Leveraged modern technologies like Next.js to deliver a fast and scalable platform.
- Improved workflows for self-driving AI model development.
Technologies: React, Node.js, JavaScript, TypeScript, Storybook, Cypress, Redux, Snowflake
Lead Front-end Developer (via Toptal)
2020 - 2022
Optimal Ship
- Architected the front-end solution to handle international and domestic shipments.
- Participated in analysis and gathering of business requirements.
- Implemented the marketing site for product promotion on Next.js.
Technologies: React, TypeScript, Next.js, React Redux, HTML5, Tailwind CSS, Test-driven Development (TDD), Jest
Lead Front-end Developer
2017 - 2020
Freedom Robotics
- Provided general front-end system architecture, which gradually migrated from an initial prototype into a successful live product.
- Combined the speed of development required for a startup with high code quality.
- Created custom DataBuffer structure to upload and cache data in real time via custom HTTP pulling mechanism.
- Developed a number of Canvas-based visualization components based on the project's custom design.
- Implemented robot piloting using different inputs, including a keyboard, mouse, and gamepad, via a WebRTC connection.
Technologies: Data Virtualization, WebRTC, D3.js, Redux, React, React Redux, HTML5, HTML Canvas, Test-driven Development (TDD), Jest
Lead Full-stack Developer
2017 - 2017
FronteraLand (via Toptal)
- Led the development of an MVP for a real estate crowdfunding investment startup.
- Wrote most of the back-end logic and supervised client-side development.
- Set up CI and provided production deployments workflow.
- Coordinated the work of other team members providing high code quality in general.
Technologies: Heroku, Sequelize, PostgreSQL, TypeScript, Express.js, Bootstrap, Redux, React, React Redux, HTML5
Senior Full-stack Developer
2014 - 2016
Fract
- Supervised a complete rewrite of the Fract platform using a modern JavaScript stack.
- Developed a back end on Express.js using both MongoDB and PostgreSQL for storage.
- Migrated data securely from old DB schema and external public sources (API, dataset files).
- Built a complex single-page client app using Vue and Google Maps.
Technologies: Vue, MongoDB, Node.js, HTML5
Senior JavaScript Developer | Senior .NET Developer
2013 - 2015
Orchard Marketing
- Implemented a travel request management system, which helps travel consultants to organize trips to get workers to remote job sites around Australia.
- Developed a complex single-page application in AngularJS.
- Developed an eCommerce site for a magazine publisher.
Technologies: Microsoft SQL Server, Entity Framework, ASP.NET MVC, REST APIs, Bootstrap, AngularJS
Senior Node.js Developer | Senior .NET Developer
2013 - 2015
Ticketek
- Integrated a Node.js app with the Microsoft tech stack.
- Orchestrated REST API calls to migrate ticket data to a new season with full business rule compliance.
- Developed the Australian Open Fan Marketplace website.
- Built complex integrations for the existing Ticketek infrastructure into a new eCommerce website.
Technologies: ASP.NET MVC, Node.js, REST APIs
Senior .NET Developer
2012 - 2013
Readify
- Migrated bank software from Oracle to a SQL Server database unifying DAL between different applications.
- Created a business management portal system responsible for organizing logistical information about coal delivery contracts.
- Worked on performance testing and optimization for a video conferencing project for a major Australian bank.
- Supported and developed new features for AIMIA loyalty management system.
Technologies: REST APIs, Microsoft SQL Server, JavaScript, ASP.NET MVC
Lead Senior Developer
2008 - 2012
Globesoft
- Implemented a new module called Talent Management, which is a separate project designated to keep track of employee professional development inside a company.
- Implemented a utility that converted the old Oracle DB to a new PostgreSQL structure for big volumes of data.
- Created a custom ORM to increase productivity of DAL class creation.
Technologies: CSS, HTML, JavaScript, PostgreSQL, ASP.NET Web Forms
.NET Developer
2007 - 2008
Archer Software
- Developed the BeamWorks system (https://www.tigerstop.com/products/tigerangle/), which automatically operates a miter saw to cut predefined parts.
- Implemented an algorithm to optimize waste of wood in order to produce a particular number of different details.
- Designed and implemented automated reporting modules that streamlined data analysis workflows for production management teams.
Technologies: Optimization, Mathematics, XML, Windows Forms (WinForms)
Project History
Full-stack JavaScript Sample App
https://github.com/erik-sytnyk/contoso-expressI developed a full-stack TypeScript/JavaScript application that demonstrates enterprise-grade architecture patterns. This project was a complete remake of Microsoft's Contoso University tutorial, utilizing a modern tech stack: a React/Redux front end, a Node.js/Express back end, and a PostgreSQL database. The application features comprehensive authentication, robust logging, error handling, and a thorough testing infrastructure. It serves as a production-ready foundation for scalable web applications.
Bookmark Archive
https://github.com/erik-sytnyk/bookmarks-archiveI developed a personal productivity application designed to organize and manage browser bookmarks. Initially created as an Electron desktop app, I later redesigned it as a local web application featuring a React front end and a Node.js back end. The application offers features such as bookmark import/export, categorization, search functionality, and offline-first architecture. It addresses the issue of bookmark chaos across multiple browsers and devices, providing a centralized management system for a streamlined and efficient user experience.
MagsOnline
http://magsonline.com.au/An eCommerce site for a magazine publisher where users can buy a subscription to popular magazines as well as buy collateral merchandise.
Australian Open Fan Marketplace
A website where users who bought tickets for Australian Open Tennis event can resell their tickets.
Education
2001 - 2006
Master's Degree in Software Development | Artificial Intelligence
Dnipro National University - Dnipro
Skills
Libraries/APIs
React, REST APIs, Node.js, Vue, React Redux, jQuery, Google Maps API, Vuex, OpenAI API, D3.js, WebRTC, Entity Framework, Windows Forms (WinForms), Pydantic
Tools
Sequelize, Webpack, Git, WebStorm, Claude, Figma
Languages
HTML, CSS, TypeScript, JavaScript, HTML5, GraphQL, XML, Python, Snowflake
Frameworks
Express.js, ASP.NET MVC 5, Next.js, Jest, React Native, AngularJS, Bootstrap 3+, Redux, ASP.NET Core, Tailwind CSS, ASP.NET MVC, Bootstrap, ASP.NET Web Forms, Ionic, Cypress, Svelte, Flask, Electron, .NET
Paradigms
Object-oriented Programming (OOP), Agile Software Development, Asynchronous Programming, Test-driven Development (TDD), Continuous Integration (CI), Model Context Protocol (MCP)
Platforms
Visual Studio Code (VS Code), Windows, Heroku, Firebase, Parse, Vercel, MacOS, Linux, CrewAI, AWS IoT, Docker
Storage
PostgreSQL, MongoDB, Microsoft SQL Server, SQLite
Other
Back-end Development, HTML Canvas, Full-stack Development, Axios, APIs, Supabase, Prompt Engineering, Cursor AI, API Integration, CI/CD Pipelines, OpenAI, Large Language Models (LLMs), Artificial Intelligence (AI), AI-generated Code, Multi-tenant SaaS, Data Virtualization, Mathematics, Optimization, User Interface (UI), Pixel Perfect, Algorithms, Linear Algebra, Discrete Mathematics, Joi, Storybook, Flowise, LangChain, FastAPI, Machine Learning Operations (MLOps)
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