Sebastian Koszuta
Verified Expert in Engineering
User Experience (UX) Developer
Sebastian is a motivated and creative problem solver with excellent communication skills and comprehensive experience. He's devoted to building UIs that exceed expectations and provide an outstanding user experience. It's his pleasure to write code that is reusable, scalable, and easy to maintain, and he eagerly contributes to business analysis with his knowledge and ideas. When working with Sebastian, expect kindness, enthusiasm, and professionalism.
Portfolio
Experience
Availability
Preferred Environment
React, Vue, Node.js, Jest, Cypress, Gatsby, TypeScript, Dashboards, Data Visualization, Strapi
The most amazing...
...project I worked on was the dashboards module at Crunch. It was a greenfield project which I had the honor of architecting.
Work Experience
Front-end Developer
Freelance
- Developed a situation room dashboard with custom D3 visualizations for a major public transport operator.
- Built dashboards with a drag-and-drop customizable layout for a cyber security risk intelligence provider.
- Implemented a lightning-fast, responsive, and SEO-optimized website for a sustainable energy transformation think-tank built with Gatsby and Strapi. Gained hands-on experience with GraphQL.
- Built an autonomous crane controller with a web interface for an art installation in a public space. Designed and implemented the solution based solely on the customer's idea. Successfully predicted and satisfied the customer's needs.
- Implemented a 360-degree zoomable viewer of high-resolution pictures for the automobile industry. Applied Microsoft Deep Zoom and OpenSeadragon.
- Built an interactive remote musical performance experience with the use of TensorFlow machine learning models for pose recognition and WebSockets.
- Implemented interactive visual experiences for the web involving TensorFlow machine learning models, WebGL, and custom OpenGL shaders.
Front-end Developer
Crunch.io
- Developed a SaaS data analytics platform for the market research industry with a strong focus on user experience.
- Architected and implemented a dashboard builder, including a drag-and-drop layout, resizable tiles, customizable visualizations (colors, dimension show/hide, dimension reorder, label editing, axis rescaling), dynamic filtering, and branding.
- Proposed and implemented architectural solutions to migrate from AngularJS to React.
- Proposed and implemented build tool reconfiguration to achieve faster build times and optimize production package size.
- Configured Cypress E2E testing and integrated it with the company's CI pipeline.
- Took part in recruitment by contacting and interviewing candidates.
- Worked remotely, in a globally distributed team.
Front-end Developer
IGT - International Game Technology
- Developed a comprehensive back office application for state lotteries. It encompassed all lottery operations, from managing relationships with ticket resellers to reward payouts.
- Implemented forms and data grids with responsive layouts and robust data validation.
- Proposed and initiated the refactoring of stylesheets across the whole application and introduced a style guide.
- Redesigned and implemented the authentication module from scratch.
- Proposed and implemented build tool reconfiguration to achieve faster build times and optimize production package size.
- Migrated the app from Gulp and Babel to Webpack and TypeScript (refactoring and configuration).
- Implemented customizable KPI dashboards for users of the back-office application.
- Worked on-site with the state lottery of North Carolina (our customer) during the deployment of our new product. Provided the customer with necessary technical support.
Front-end Developer
Showroom
- Developed an eCommerce platform for independent fashion designers. The platform quickly became its market leader, and our task was to scale the technology up accordingly.
- Architected the front-end of the customer-facing website at Showroom.pl.
- Developed a custom eCommerce management system. It involved brand relationship management tools, custom statistics, shipping company API integration, stock management, etc.
- Promoted to team leader in August 2014. Managed a team of three front-end developers.
- Configured front-end build tools and developed core modules such as Auth, routing, or API communication services.
- Integrated with Facebook OAuth and UPS Shipping API.
Intern Front-end Developer
Orange Labs
- Designed and developed an online conferencing Flash application and an accompanying website.
- Integrated the Flash app with a Wowza media streaming server.
- Developed a Flash module that allowed the creation and live-streaming of vector and bitmap content for remote users.
- Integrated an SMS getaway as part of a new feature for the website.
Experience
Lottery Management System
Showroom
Skills
Languages
HTML, CSS, JavaScript, CSS3, TypeScript, Sass, Less, GraphQL, SCSS, PHP, SQL, Python, Java
Frameworks
Jest, Redux, Bootstrap, Material UI, YARN, Angular Material, UI-Router, JSON Web Tokens (JWT), Tailwind CSS, Cypress, React Native, Express.js, Fastify, OAuth 2
Libraries/APIs
React, React Router, jQuery, Node.js, D3.js, Lodash, REST APIs, Vue, TensorFlow, WebGL, Three.js, Google Maps API, Plotly.js, React Redux
Tools
GitHub, Webpack, Git, Babel, NPM, Grunt, Flash, Wowza, Bower, Yeoman, Jenkins, Redux Thunk, Jira, OpenSeadragon, Front-end Build Tools, Plotly, Figma
Paradigms
REST, Responsive Web Design (RWD), Agile Software Development, E2E Testing
Other
Styled-components, Front-end Development, Front-end, Data Visualization, API Integration, Dashboards, Interactive Dashboards, Analytical Dashboards, UI Testing, User Interface (UI), Art, User Experience (UX), APIs, SaaS, Software as a Service (SaaS), Web Development, Full-stack Development, Strapi, eCommerce, Full-stack, Design, Gatsby, Creativity, Aesthetics, Communication, Software Development, Multimedia, Cube.js, WebSockets, Storybook, Internet of Things (IoT), OAuth, Single Sign-on (SSO), Charts, Software Architecture
Platforms
MacOS, Raspberry Pi, Raspberry Pi 3 GPIO, Arduino, Amazon Web Services (AWS)
Storage
PostgreSQL, MySQL, Databases, Amazon S3 (AWS S3)
Education
Bachelor of Fine Arts in Fine Arts
HKU University of the Arts - Utrecht, The Netherlands
Bachelor's Degree in Information Technology
Polish-Japanese Academy of Information Technology - Warsaw, Poland
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring