Projects: - cere.network/hub/bridge (blockchain bridge for crosschain transfers) - cere.network/hub/stats-app (aggregated blockchain statistics) - cere.network/hub/explorer (blockchain explorer) Implemented: - blockchain monitoring integration with Grafana to visualize corporate blockchain account balances metrics; - BetterUptime integration with Slack to send notifications about corporate account balance issues; - Grafana monitoring dashboards (for blockchain nodes, networks, balances); - migration of all blockchain tools (Bridge, Stats, Explorer) to the latest blockchain node version to make them up-to-date and usable with the latest node version; - money transfer fallback mechanism in the Bridge UI app to visualize transfer transaction status to users; - blockchain liquidity check in the Bridge UI app to reject at the beginning of the transfer flow, so that it won't be rejected; - Google Analytics integration in Bridge UI to be able to collect information about users' behavior, and blockchain transfers; - WalletConnect integration in Bridge UI to connect users' wallets by scanning a link from a mobile phone; - Bridge backend RPC providers diversification to make blockchain more stable and independent from a single RPC provider; - Bridge backend app integration and load tests to check the system stability; - maintenance mode mechanism for Bridge UI, Stats, Explorer tools to enable maintenance mode during app updates; - liveness/readiness API in blockchain tools backend apps for k8s integration; - DEX analytics application data model in Google BigQuery integrated with lambdas; - fixed blockchain tools audit issues; - fixed bugs on the backend, UI (memory leak, MetaMask, WalletConnect, blockchain node integration, logical errors); Technologies: Blockchain, EVM, Web3.js, Ethers.js, Polkadot.js, Substrate, JavaScript, Node.js, Typescript, GraphQL, ReactJS, Redis, PostgreSQL, TTD and BDD, DDD, CI/CD (Github Actions), Microservices Architecture, AWS, Kubernetes

Projects: - lanistar.com (bank card and wallet platform) Implemented: - bank accounts module in the API service, which helped to integrate with the bank payment platform; - influencers CRM backend and front-end microservices (some parts), which provided a convenient way to manage the company's marketing activity; Technologies: JavaScript, Node.js, Typescript, Nestjs, GraphQL, Vue, Vuetifyjs, Redis, PostgreSQL, HTTP, TTD and BDD (jest, supertest), DDD, CI/CD (Github Actions), Microservices Architecture, Amazone AWS (ELB, EC2, S3, RDS), Kubernetes

Projects: - xara.com (document design, managing, and processing platform) Implemented: - local development installation involved 21 microservices with several code architectural layers, which scaled independently in Kubernetes; - ReCAPTCHA v2, v3 mechanisms for API service, which helped to protect against brute force attacks; - MongoDB data migration script, which helped to update the company's business logic; - technical design for a caching mechanism based on Redis to optimize the company templates speed of processing; - lambda scripts; - logging mechanism in Kibana used to monitor request speed; - Kubernetes integration with MongoDB, Redis, Redis-cluster, Nats services; - Kubernetes integration with Fluentd logging agent; - Scaffold integration for the development team; - Nginx image building in TeamCity; - MongoDB replica set and Redis cluster in the local environment; - dashboard in Graphana to monitor the Kubernetes cluster; - application for company templates migration based on Nodejs streams; - integration tests and unit tests, which revealed app bugs and increased the development time and quality; - bug fixing in apps. Technologies: JavaScript, Node.js, ReactJS, Redis Cluster, MongoDB, Nats, HTTP, Websocket, TTD, and BDD (mocha, nyc, supertest), DDD, CI/CD (Teamcity), Microservices Architecture, Amazon AWS (ELB, EC2, S3, RDS, DynamoDB), Kubernetes, Scaffold, ELK (Elasticsearch, Kibana, Logstash)

Projects: - sportytrader.com (sports betting trading platform) Implemented: - 3 microservices (API, Orders, Admin) with several code architecture layers, which scaled independently; - integration with a 3rd-party API (live, match, single bets data), which reduced the project launch time and development costs; -odds, stocks, games, socket.io rooms, which provided fast communication between client/server apps; - message bus in Redis, which provided internal communication between microservices; - several logical modules (transactions, games, bets, odds, standings, users, news, countries); - graphs building using Google Chart API that reduced the visualization implementation time and costs; - caching mechanism for all microservices in Redis, which speeds up the client/server communication time; - integration tests and unit tests, which revealed app bugs, reduced development time, and increased code quality; - application tuning for high load (requests pool management, memory optimization, AWS infrastructure optimization), which helped to reduce the infrastructure costs; - communication with the business to prepare tasks for the team, business information transformation to technical tasks for backend/frontend team members to organize the development process. Technologies: JavaScript, Node.js, Express.js, Redis, MySQL, HTTP, Websocket, TTD and BDD (mocha, nyc, supertest), DDD, CI/CD (Jenkins), Microservices Architecture, Amazon AWS (ELB, EC2, S3, RDS, DynamoDB), Kubernetes, ELK (Elasticsearch, Kibana, Logstash)

EDETEK Inc. logo Senior Javascript / Nodejs Developer Remotely Senior Javascript / Nodejs Developer Remotely EDETEK, Inc. · ContractEDETEK, Inc. · Contract Sep 2017 - May 2018 · 9 mosSep 2017 to May 2018 · 9 mos United StatesUnited States Projects: - MDR (medical standards logic service), - CDL (medical content delivery service), - Validator (medical xpt files validator service), - Parser (medical xpt files parser service) Implemented: - parsing medical standards from XML and TXT formats into the MDR app and transforming them to the relational DB that created core app logic; - integration, unit tests for CDL, which revealed app bugs and increased the development time and quality. - xpt files asynchronous parsing and validation using Nodejs streams, which helped to increase performance several times (it took 1 min to parse 20mln records); - Nodejs C++ addon for IBM numbers converting, which increased performance twice compared to the JavaScript implementation. Technologies: JavaScript, Node.js, HTTP, Redis, MySQL, TTD and BDD (mocha, nyc, supertest), DDD, CI/CD (AWS), Microservices Architecture, Amazon AWS (ELB, EC2, S3, RDS, DynamoDB, SQS).

Projects: - Fibiz: aciety.com/portfolio/fibiz (binary options trading platform) Implemented: - backend trading app for Android, iOS, and desktop clients; - some parts of the browser UI trading app; - several logical modules (quotes, orders, users, authentication, balance, profile management, payments, system risk management, integration with CRM); - extremely fast communication between server and client. On the server side, it takes 4ms to open an order and less than 200ms to send a request from the client to the server through the network; - integration with social networks API (Facebook login, Google login, in-app purchase, Cooladata storage, Appboy push notifications); - development process management inside the team, code review. Technologies: JavaScript, Node.js, NGINX, Websocket, Socket.io, HTTP, Redis, MySQL, Kafka, TTD and BDD (mochaframework), DDD, CI/CD (Jenkins), System Monitoring (Datadog), Microservice Architecture, Amazon AWS (MKS, ELB, EC2, S3, RDS, DynamoDB).

Projects: - vreoinnovation.com (corporate site with e-commerce); - Internmasters: https://instagram.com/internmasters (hiring platform). Implemented: - Vreoinnovation backend, UI from scratch. - Internmasters backend, UI from scratch Technologies: Responsive web design, HTML5, CSS, JavaScript, Bootstrap, jQuery, AJAX, AngularJS; PHP, Laravel, WordPress, MySQL, NGINX, HTTP, TTD and BDD (PHPUnit), DDD, Microsoft Azure (Virtual Machines, SQL Database, Storage).

Projects: - ddos-guard.net (DDOS attack protection platform) Implemented: - billing system for staff and clients with several logical modules (orders, products, categories, invoices, payment systems, services, ticket system, client hosting management); - integration with payment systems (PayPal, Webmoney, Yandex. Money, SpryPay, Airpay); - dashboard integration with a Node.js application that sends metrics from hosting servers in real-time every second. Technologies: Responsive web design, HTML5, CSS, JavaScript, Bootstrap, jQuery, AJAX; PHP, CodeIgniter, MySQL, NGINX, HTTP, Node.js, Socket.io.

Projects: - harbortouch.com (point-of-sale browser app) - draken.aero (corporate website) - Quoteka: 3atdev.com/ru/projects/quoteka (quotes search service) Implemented: - WordPress engine integration with HTML markup, Sphinx search engine integration; - WordPress plugins creation and modification; - a point-of-sale platform that allows maintaining client orders and reservations, room, and furniture arrangement on JavaScript. Technologies: HTML5, CSS, JavaScript, Jquery, AJAX; PHP, WordPress, MySQL, NGINX, Apache, HTTP, Sphinx SE.

Projects: https://twitter.com/meandmyapp Implemented: - Wordpress integration with html markup; - dashboard with settings for social networks integration (Facebook, Twitter, Pinterest, Google Plus+,Instagram); - user registration/authentication, profile managing, theme design settings, social networks sharing and feed. Technologies: HTML5, CSS, JavaScript, Jquery, AJAX; PHP, Wordpress, MySQL, NGINX, HTTP.

Projects: - christianbooks.odessa.ua (books e-shop) - MeAndMyApp: twitter.com/meandmyapp (social networks integrator app) Implemented: - christianbooks.odessa.ua backend, UI books from scratch; - MeAndMyApp WordPress backend, UI from scratch. Technologies: HTML5, CSS, JavaScript, Jquery, AJAX; PHP, WordPress, MySQL, NGINX, Apache, HTTP.

Faculty of Informatics and Computer Science, Software Developer