Sergiy Onenko
Verified Expert in Engineering
Full-stack Web Developer
Rzeszow, Poland
Toptal member since May 22, 2019
Sergiy is an adept full-stack developer with experience at renowned companies like Cityblock and NewMotion (Shell Recharge). Honing his expertise at Europe's premier electric car charge network, he has successfully developed apps from inception, enhanced mature projects, and contributed to several startups, three of which have flourished. Sergiy excels in aligning systems to Google's high standards.
Portfolio
Experience
- Web Development - 12 years
- Data Visualization - 8 years
- TypeScript - 5 years
- Algorithms - 4 years
- React - 3 years
- Chrome Extensions - 2 years
- Solidity - 1 year
Availability
Preferred Environment
Visual Studio Code (VS Code), Git, Scrum, React, Next.js, GraphQL, PostgreSQL, Notion, React Apollo, Apollo Server
The most amazing...
...contribution I've had was with Cityblock, a Google subsidiary's healthcare app. Enhanced Europe's top EV charging network at NewMotion (Shell).
Work Experience
Senior Engineer
Cityblock
- Contributed to its success by suggesting improvements and actively driving innovation within the team. My suggestions for architectural enhancements were implemented, allowing other developers to build upon the foundation I created.
- Took on the responsibility of mentoring and guiding fellow developers, assisting them in improving their skills and achieving their full potential. By fostering a collaborative environment, I promoted knowledge-sharing and teamwork.
- Improved the Scrum process and implemented strategies that enhanced efficiency and effectiveness. The team achieved streamlined workflows and improved project delivery timelines through my insights.
- Recognized the importance of thorough testing. I optimized test speed, resulting in faster iterations and increased overall development productivity.
- Developed new features, resolved bugs, and enhanced GraphQL solutions. Collaborated with designers and leaders to seamlessly integrate design requirements, offering continuous valuable input.
Freelance Developer
Toptal Projects
- Created the skeleton for a complex TypeScript/React Chrome extension and built a great development team that took the extension to the next level, porting it to mobile platforms.
- Created the functional design for a cross-platform application, "Startup in Stealth Mode."
- Configured an AWS deployment process, Amazon EC2, Bash Script, PostgreSQL, and SSL.
- Collected requirements for every next feature set and made demos and standups.
- Implemented the application, including authentication (Google and email), authorization, file upload, messaging, and user management.
Technical Lead
NewFirePartners
- Designed and developed the micro frontend architecture for the existing Angular 5 app.
- Created a better development process and introduced new build commands that allow switching between development environments without needing to dig tons of documentation.
- Improved all team (30+ developers) development speed by reducing application build time in development mode five times.
- Created and contributed to the core library used across all pluggable applications.
- Shared knowledge with the team and distributed teams.
Co-founder and Architect
Pubium
- Designed and developed an application from scratch, including delegation to other developers. Fully controlled step-by-step implementation, introducing the Scrum process.
- Created the back end for the management portal, including the roles system.
- Designed the restaurant portal's front-end development for other developers, allowing them to register restaurants and manage tables, days, hours, and reservations.
- Designed and implemented POC for the RESTfull back-end app.
- Created the notifications application for push notifications across all existing infrastructure.
- Set up all development and production environment,s including Docker and Swarm.
- Integrated the application with socials and mail services.
- Coached and translated the most important knowledge to the team.
Senior Web Developer
IDMC
- Architected and developed the front end for web-based healthcare applications from scratch.
- Designed and developed the REST layer for the application.
- Added complex role, permission, and restriction system for users.
- Developed Elasticsearch-based aggregations and translated them to visualizations and tables.
- Created complex filters system using tables and charts.
- Contributed to Kibana, where we needed additional features.
- Implemented a system that alerts if microorganisms evolved resistance to certain antibiotics.
Software Developer
Shellcharge
- Designed and developed a RESTful application to enable partner integrations with our services.
- Contributed to the main web application, Account.shellrecharge.com. It allows users to manage their charge points, shows available charge points on the map, manages subscription plans, etc.
- Contributed to the central application responsible for managing the behavior of charging points.
- Computed payments for charge point usage, thus contributing to the application.
Lead JavaScript Developer
Samsung R&D Ukraine
- Designed and crafted a mobile UI library using JavaScript, HTML5, and CSS3 for an e-book RIA framework, which was integrated with C#.
- Acted as the lead developer, chief architect, and team lead.
- Enhanced proprietary libraries for the Tizen operating system using C++.
- Enhanced the Kies Air mobile app by adding compatibility for additional screen resolutions, devices, and features like photo previews.
Lead Full-stack Developer
OS-Direct
- Designed a web app for team management with features like photo uploads, data entry, chart visualization, and PDF reports. Incorporated a robust role system for varied users.
- Developed a web-based application for live streaming conferences featuring a pre-moderated chat and a sophisticated role management system.
- Built a data visualization application with comprehensive filtering and grouping capabilities for in-depth analysis.
- Developed landing pages for esteemed, major clients.
Web Developer
Lumostestprep
- Designed a web solution for educators to create courses and share articles.
- Integrated video uploading and course content editing features.
- Linked the platform with a student portal for course access and test-taking.
Experience
NewMotion
https://my.newmotion.comSenior Engineer
https://www.cityblock.com/Certifications
Hacking with WatchOS 4
Udemy
Complete Sketch 5 Course
Udemy
The Complete iOS Bootcamp Development
Udemy
Principles of Reactive Programming
Coursera
Functional Programming Principles in Scala
Coursera
Skills
Libraries/APIs
REST APIs, jQuery, React, Node.js, Chart.js, Google Chart API, Akka Streams, Leaflet, Google Maps, RxJS, Babylon.js, Slick, spray
Tools
Git, ScalaTest, Karma, Webpack, YouTrack, Knex.js, Jira, IntelliJ IDEA, Xcode, Subversion (SVN), Figma, Sketch, Gulp, RabbitMQ, Bower, Canvas 2D, SBT, Kibana, Docker Swarm, Notion, React Apollo
Languages
CSS3, HTML5, JavaScript, TypeScript, Scala, SQL, CSS, Sass, Less, ECMAScript (ES6), Bash, C++, C, PHP, GraphQL, Python, Solidity, Swift
Frameworks
Angular, JSON Web Tokens (JWT), Bootstrap, Express.js, Ionic, Play 2, AngularJS, Protractor, Apache Camel, Ionic 4, Next.js, Ext JS, Play Framework, Akka, Kendo UI, Lift, Chrome, Flutter, React Native, Cypress
Platforms
Godot, Visual Studio Code (VS Code), OS X, Linux, NetBeans, MODx, Amazon Web Services (AWS), Arduino, Raspberry Pi, WatchOS, iOS, Docker, Meteor, DigitalOcean
Storage
PostgreSQL, Elasticsearch, MySQL, MongoDB, Realm
Paradigms
Dependency Injection, Testing, Unit Testing, E2E Testing, Functional Programming, Scrum, Kanban, HL7 FHIR Standard, REST
Other
Web Development, AmCharts, Data Visualization, Maps, Chrome Extensions, Front-end, Algorithms, Akka Actors, Akka Persistence, Integration Testing, Safari Extensions, Architecture, Non-fungible Tokens (NFT), ClickUp, Silhouette, HAL, Akka HTTP, Regression Testing, Machine Learning, Coaching, Leadership, OOP Designs, HL7, WebSockets, Domain-driven Design (DDD), Crypto, Bcrypt, Apollo Server, Mentorship, Full-stack
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