Full-stack Developer
2019 - 2019VarageSale (via Toptal)- Reengineered an ads implementation.
- Contributed to solving app bottlenecks in high-load areas.
- Added new functionality for a member support microservice.
- Migrated emails from Mailgun to SendGrid.
- Made the app less coupled to the notifications microservice.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Microservices, Fluentd, Sidekiq, MySQL, Ruby on Rails (RoR), Ruby, ReactLead Developer
2018 - 2019WinOrLose (via Toptal)- Supported the web-desktop, web-mobile, iOS, and Android platforms.
- Built an MVP in two months.
- Developed a sophisticated feed algorithm.
- Implemented real-time updates, chat, payments, voting, commenting, filtering, an authorization flow, settings, and profile.
- Created it all from scratch.
- Worked on the full cycle of the build, deployment, and push to the Google Play and App Store.
Technologies: JavaScript, Redux, Storage, Hosting, Authentication, Functions, Firebase, Cordova, ReactChief Architect
2018 - 2018BidWrangler- Solved the n+1 issue which had acted as the server bottleneck.
- Introduced caching for the Redux selectors.
- Created an "auction progress" feature.
- Worked remotely with a team spread across the US, Ukraine, Poland, Portugal; used GitHub, Slack, and Zoom.
- Increased test coverage from 75% to 90%.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Ruby, AWS Elastic Beanstalk, Google Places API, Capybara, Stripe, Auth0, Firebase, Google Maps, Airbrake, Enzyme, Jest, Material-UI, Redux-saga, Redux, Webpack, MySQL, Ruby on Rails (RoR), ReactFull-stack Developer
2016 - 2018Clade- Developed the front-end of an admin tool app (React).
- Implemented a Clubhouse-GitHub integration.
- Consulted on the back-end of a GraphQL server's maintenance and set up.
- Created a mechanism for universal email templates for SendGrid synchronization and customization.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Heroku, HockeyApp, Fastlane, Prismic, Google Places API, Scrum, SendGrid, Litmus, Surge Proxy Server, Mocha, Karma, Draft.js, Styled-components, Reselect, Redux Form, Redux-saga, Redux, GraphQL, Apollo, Webpack, Node.js, React Native, ReactTeam Leader
2016 - 2017Watchtower- Worked remotely with a team in the US; used Trello, Slack, and Skype to communicate.
- Conducted code reviews for other developers.
- Solved performance issues for the main page with a heavy functionality.
- Created the architecture for the front-end of a web application with real-time updates.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Ruby, Amazon API Gateway, Heroku, Webpack, ECMAScript (ES6), Normalizr, React-Bootstrap, Redux-saga, CSS, Redux, React, Capistrano, REST, PostgreSQL, Ruby on Rails (RoR)Front-end Developer
2016 - 2016A Job Board for Freelance Work- Implemented a freelancer onboarding flow.
- Provided support for video interviews.
- Implemented designs according to Material Design guidelines.
- Developed Payoneer integrations and a massive payment management tool.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Redux, Heroku, Webpack, ECMAScript (ES6), Material-UI, Redux Form, Redux-saga, CSS, ReactSenior Full-stack Developer
2015 - 2016Chairlift- Upgraded the application from Rails 3 to Rails 4.
- Designed and integrated an extensible ACL system with 100% coverage of endpoints on top of Pundit.
- Successfully migrated to a SPA architecture.
- Increased the readability and comprehensiveness of the application by 100% by cleaning up more than 100,000 lines of legacy code.
Technologies: JavaScript, SQL, Ruby, Cucumber, RSpec, Slack, Material-UI, MySQL, Gulp.js, React, Polymer, Ruby on Rails (RoR)Full-stack Developer
2013 - 2015LevelUp- Worked as a semantic algorithms domain leader.
- Increased the performance of a keyword tree generation 550 fold by inventing a new algorithm, optimizing SQL queries, and intensively using caching approach.
- Successfully migrated a product from Padrino to Ruby on Rails 4.
- Increased the collection rate from 500 to 50,000 keywords/hour by optimizing the database usage, using a Redis cache, improving the process flow, and separating concerns.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Ruby, RSpec, Sidekiq, Secure Automated Lending Technology (SALT), Elastic, MongoDB, Redis, PostgreSQL, Knockout.js, Sinatra, Ruby on Rails (RoR)Lead Developer
2012 - 2013Cowries Bills- Set up an integration with the Stripe payment service.
- Created multi-wallet support for international customers.
- Implemented a background multi-process service to handle highly sensitive data.
Technologies: JavaScript, SQL, Ruby, Stripe, Payment Processing, Clickatell, Heroku, PostgreSQL, Ruby on Rails (RoR)Full-stack Web Developer
2012 - 20133TAPS- Increased the performance from 100 to 400 requests/sec.
- Developed an API protocol.
- Implemented search, filter, sort, statistics, preview, and favorites modules.
Technologies: JavaScript, SQL, MySQL, Backbone.js, Ruby on Rails (RoR), RubyFull-stack Web Developer
2011 - 2012DOCOMO- Implemented calculation and management different leave types for employees in all countries, places, and time zones.
- Worked as a reports domain owner.
- Installed a state machine to handle the leaves states flow.
Technologies: JavaScript, SQL, jQuery, PostgreSQL, Ruby on Rails (RoR), Ruby