Arthur Chumak

Senior Node.js Backend Engineer with 9+ years building scalable services on AWS and Node.js. Experienced in performance & cost optimization, real-time systems, large-scale data migrations, and production-grade testing. Strong focus on clean architecture, design patterns, and delivering measurable business impact.

Skills / Tech stack:

• Backend: Node.js, Express, AWS, MongoDB, SQL, WebSockets
• Cloud & Infra: AWS (Lambda, DynamoDB, EC2), Firebase, Google Cloud
• Databases: MongoDB, DynamoDB, MySQL, OracleDB, Redis
• Testing: Jest, Puppeteer, E2E, unit testing
• Frontend: Angular, Vue
• Other: WebSockets, Stripe, CI/CD, RabbitMQ

Education: 2013 - 2017 “Computer science” bachelor’s degree at Belarusian State University of Informatics and Radioelectronics

Languages:

• English B2 Upper-Intermediate

Contacts:

• linkedin
• github
• arthurchumak@gmail.com

Professional Experience:

Freelance / Pet Projects

Fullstack Developer · Jul 2024 – Present · Node.js, Vue.js, Firebase, Google Cloud

• Building fullstack applications with focus on scalable architecture, real-time features, and cost-efficient cloud infrastructure

Whitesharx – Chess Game

Team Lead Backend Developer · Apr 2022 – Apr 2024 · AWS, Node.js, MongoDB, Redis, WebSockets

• Led a 3-person backend team responsible for the core game services and infrastructure
• Reduced infrastructure costs by more than 50% through architecture redesign, query optimization, and resource right-sizing
• Significantly improved system performance and stability while delivering multiple new real-time game mechanics
• Designed and implemented Stripe subscription billing and payment flows
• Refactored and modernized a large legacy Node.js codebase, improving maintainability and reducing technical debt
• Established CI pipelines for linting, testing, and automated quality gates

ScienceSoft – Football Fan Club

Fullstack Developer · Feb 2021 – Jan 2022 · AWS, Node.js, Angular, TypeScript, RxJS

• Designed and delivered backend APIs with Swagger/OpenAPI documentation that enabled seamless integration with the mobile team
• Successfully migrated ~10 million records from third-party services to AWS with zero data loss and minimal downtime
• Provided ongoing technical support and API guidance to the frontend team, accelerating feature delivery

ScienceSoft – MVP Agriculture

Angular Developer (Fullstack contribution) · Aug 2020 – Feb 2021 · Node.js, Angular, RxJS, TypeScript, Ant Design

• Bootstrapped the entire frontend application from scratch and established the core architecture
• Designed and built a reusable component library and shared page layouts that accelerated development across the product
• Integrated the frontend with backend services and delivered a working MVP for agricultural process automation and metrics collection

ScienceSoft – Employees Data Aggregator

Fullstack Developer · Jul 2019 – Jul 2020 · AWS (Lambda, DynamoDB, Cognito, S3), TypeScript, Node.js, Express, Angular 8, Puppeteer

• Designed and implemented scalable CRUD APIs on AWS (Lambda + DynamoDB) for a multi-tenant analytics platform
• Built and executed large-scale data migration pipelines
• Developed end-to-end automated tests with Puppeteer covering critical user flows, significantly improving release confidence
• Created and published reusable Angular view components as a shared internal npm package
• Stabilized and fixed production issues across multiple Angular applications

Bamboo Group – Learning Management System (LMS)

Backend Developer · Jul 2018 – Jul 2019 · TypeScript, Node.js, Express, Sequelize, MySQL, RabbitMQ, Jest

• Designed a highly generic and reusable CRUD module system using Sequelize + TypeScript that drastically reduced development time for new features
• Built and published a fully typed API client as an internal npm package, enabling type-safe consumption across teams
• Implemented E2E test suites that leveraged the shared API client, improving overall test coverage and reliability

Bamboo Group – Paperless Office

Fullstack Developer · Jul 2017 – Jul 2018 · Node.js, Express, Socket.io, MySQL/OracleDB, Redis, LDAP, Vue.js, Jest

• Delivered the MVP of an electronic document signing platform supporting interactive pen displays
• Architected and built 3 frontend applications sharing a common codebase and design system
• Designed real-time WebSocket API with room-based user sessions for collaborative document workflows
• Integrated the system with customer databases and LDAP user stores
• Established unit testing practices for core modules, improving code quality from the early stages

Bamboo Group – CRM Microservices

Fullstack Developer · Jan 2017 – Jul 2017 · Node.js, Express, MySQL, Redis, LDAP, AngularJS

• Developed and maintained CRM microservices with third-party API integrations
• Provided ongoing support and bug fixing for legacy services while ensuring system stability