Used technologies: TypeScript, NodeJs, MongoDB, Kafka (Queue) PostgreSQL, Redis, GraphQL, ExpressJS, NestJs. Tests: Mocha, Jest, Ava, integration tests for routes (supertest), mongodb testing library and e2e tests with Cypress. Frontend: React, Nextjs, Redux, Styled Components, scss/sass. For containers and deployment: Docker, k8s, Terraform, AWS, CircleCI. > Automated a toxicity check for user comments using perspective API, which decreased 80% of manual work of moderators. > Built a scalable tracking system for monitoring user interactions which handled hundreds events per second using Kafka queues. > Integrated an A/B-testing system that enabled multiple experiments in parallel in backend and frontend

Used technologies: TypeScript, NodeJs, GraphQL, ReactJS, NextJs, Styled Components, HTML5, CSS3. Databases: PostgreSQL, MySQL and MongoDB (introduced only in the last year). For containers and deployment: Docker, Kubernetes, G Cloud, Jenkins. Clean code and complete test coverage with unit tests (jest, mocha, enzyme), integration tests (routes and db), visual tests (screenshot comparison) and end-to-end tests (WebdriverIO, Cypress) > Performance analyses and optimization, using Lighthouse reports, automated tests and tooling. > Working in an agile environment in a self organised scrum team. > Interviewing senior developers and being involved in hiring process > Leading teams and actively participating in growing Juniors

Technologies: Ruby, Ruby on Rails, REST API with microservices.

Technologies: Ruby, Ruby on Rails, REST API with microservices, JavaScript, MongoDB, RabbitMQ, Redis. > Built an automated spam filter using prediction API that decreased 80% of spam messages sent from a webpage. > Automated an import of large amounts of data from different data sources (Api, Ftp, S3) and combined them in a NoSQL database. Optimize DB queries for filtering and aggregating billions of documents.