Worked on both server-side and client-side parts of the CALA application. On all sides of the project, including real-time updates, notifications system, payment system, pricing system, email notifications, email templates, Amazon SQS, etc. Participated in building iOS application using React Native.Used React, React Native, Redux, Typescript, Koa.js, Zod, GraphQl, Apollo, Amazon SQS, PostgreSQL, Knex.On server-side:- Added support for new asynchronous payment method… Show more Worked on both server-side and client-side parts of the CALA application. On all sides of the project, including real-time updates, notifications system, payment system, pricing system, email notifications, email templates, Amazon SQS, etc. Participated in building iOS application using React Native.Used React, React Native, Redux, Typescript, Koa.js, Zod, GraphQl, Apollo, Amazon SQS, PostgreSQL, Knex.On server-side:- Added support for new asynchronous payment method that significantly reduced the fee. It was a challenge as required to refactor the regular payment strategy because system was not designed for asynchronous methods.- Worked on performance optimizations of the app by reducing the time to response on back end. SQL queries optimizations.- Implemented a worker for the server side to postpone unnecessary updates and increase response time to the user. Together with other optimizations it allows to significantly reduce the response time on checkout.- Did careful infrastructure upgrade including updating versions of Node.js, database, etc. on many little applications. Achived almost no downtime for the service during the upgrade.On client-side:- Implemented redesign of the payment step using React. In result it simplifies further changes to support new payment methods.- Added support for 3D assets view using ThreeJS.- Highlight and "scroll to" support from notifications to concrete comments in all parts of the application.- Drag-and-drop support and redesign of canvas cards list.As an on-call engineer:- Brought incalculable joy to other teams by providing in-time support on engineering front, including immediate investigation of bugs or unexpected behaviours, detailed explanation of existing system rules and limits, bug fixing estimates and workarounds to unblock others. Show less

Worked with the team on rewriting of complicated PHP/JQuery monolith project with hight amount of visitors to React page by page. The main priority was to increase user experience and rank of the service in search results. For that we were looking at improving site results in PageSeed Insights and SEO metrics. Spent a ton of time in performance tab of developer tools to catch and understand our bottlenecks. Learned a lot about website performance optimization and browser rendering… Show more Worked with the team on rewriting of complicated PHP/JQuery monolith project with hight amount of visitors to React page by page. The main priority was to increase user experience and rank of the service in search results. For that we were looking at improving site results in PageSeed Insights and SEO metrics. Spent a ton of time in performance tab of developer tools to catch and understand our bottlenecks. Learned a lot about website performance optimization and browser rendering optimization. We reached almost 100 points in PageSpeed Insights results.In order to achieve our goals we:- Separated back end and front end by using Next.js, GraphQl and added back end for front end middle to simplify work on providing better user experience for clients.- Improved server side rendering to make it possible for crawlers to see search related information, and time to interaction for users.- Used wide amount of techniques and practices to provide information to the end clients as soon as possible. That requires deep knowledge in how browser is rendering the page, in what steps and what can lead to slowing rendering down.- Worked on increasing SEO results by providing correct page mark up, necessary tags for crawlers and right data.- Worked on better AMP support.Other activities:- Was a team leader of front-end team that worked on complex builder for tours. That role requires: deep understanding of existing system, close communication with back-end team, designer and stakeholders, planing and demoing.- Integrated Google Maps and Baidu maps with custom widgets with server-side support.- Participated in A/B testing. Show less

On this project, I worked with React on the front-end and NodeJS on the backend with MySQL db.Huge well-organized and complicated project.I had a combination of short term and long term projects that including API integrations, advanced billing features, and ongoing bug fixes.I helped the customer to optimize project structure and added new features such as invoicing, reporting, etc. We used React/Redux and Node.js/Express for this purpose. - Worked on improving… Show more On this project, I worked with React on the front-end and NodeJS on the backend with MySQL db.Huge well-organized and complicated project.I had a combination of short term and long term projects that including API integrations, advanced billing features, and ongoing bug fixes.I helped the customer to optimize project structure and added new features such as invoicing, reporting, etc. We used React/Redux and Node.js/Express for this purpose. - Worked on improving error handling and visualization for the form-rich part of the application that had wide range of different type inputs to collection energy audit information. Used React, Redux, NodeJS, PostgreSQL, Knex, Bookshelf.- Did an API integration of different third-party services.- Helped to optimize project structure to add new features as invoicing, reporting.- Wrote an integration tests for external APIs, tests for permissions.- Worked on SQL queries optimization.- Improved offline support of the application in in-app communication part to fix concurrent updates.- Added support for a Green Button Standard to simplify energy usage information upload. Show less

Worked as a Frontend and Backend developer, using React.js on Frontend and Django/Python on Backend. Used NodeJS with React for SSR (server-side rendering) to increase SEO.Worked on two projects. Campus - a platform for a University relative job search. GC5 - a platform which helps to search and connect graduates across the country with top companies all over the world.Was responsible for:- server-side rendering using React and NodeJS with Django as an API;- Dashboard… Show more Worked as a Frontend and Backend developer, using React.js on Frontend and Django/Python on Backend. Used NodeJS with React for SSR (server-side rendering) to increase SEO.Worked on two projects. Campus - a platform for a University relative job search. GC5 - a platform which helps to search and connect graduates across the country with top companies all over the world.Was responsible for:- server-side rendering using React and NodeJS with Django as an API;- Dashboard pages, forms, styling;- drag-and-drop using React;- MySQL query optimization;- SEO optimization;- bug fixing. Show less