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dkdottk

Danylo K

@dkdottk

Ruby and Node Software Engineer

Ukraine
Ukrainian, English
About me
I am a Ruby and Node.js Engineer with over 6 years of experience designing and scaling high-load, distributed systems. I specialize in architecting microservice ecosystems, building secure financial workflows, and leveraging AWS pipelines to solve complex technical problems. My approach focuses on robustness, maintainability, and aligning technical decisions with business goals.... Read more

Skills

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dkdottk
Danylo K
Offline • 

See my services

Full Stack Web Applications
I will fix and scale ruby or nodejs backend apps
From$400 / projectMore details

Work experience

Ruby/Node Software Engineer

Company • Full-time

Oct 2022 - Present • 3 yrs 10 mos

Entertainment Platform – Designed high-load microservice architecture from scratch for a fast content‑sharing app connecting artists and audiences. Implemented uploads via Presigned URL and AWS processing pipeline (MediaConvert, S3, SQS, EventBridge) with Lambda scripts handling race conditions. Created and integrated Stripe‑based payment workflows. Stack: Node.js, TypeScript, RabbitMQ, Docker, Docker‑Compose Libs and Tools: Express, Jest, Grafana, AWS SDK Services: MediaConvert, DocumentDB, EventBridge, SQS, S3, Stripe, SendGrid Money Transfer App – Developed a global payment platform supporting debit, credit, refund, and return transactions via SWIFT, SEPA, ACH, CHAPS. Designed configurations and core payment logic, integrated status tracking, and managed real/virtual accounts. Built core app architecture with microservices and internal libraries. Delivered transaction‑ingestion services via SFTP from major banks (JP Morgan, Bank of America, etc.) with automated reconciliation. Maintained pipelines, created an admin panel for support teams, and contributed to sprint planning. Stack: Ruby, Grape, Sinatra, Rack, MongoDB, PostgreSQL, Docker, Docker‑Compose, AWS (self‑hosted deploy), GitLab CI/CD, RabbitMQ Tools: S3, SumoLogic, NewRelic, Sentry, Okta, Honeycomb Libs: RSpec, FactoryBot, Capybara, Cucumber Boat Data API – Built a microservice to collect and serialize water transport data (general info, resources, insurance) from third‑party services, delivering structured results to the main application. Stack: TypeScript, Node.js, Express, Jest

Upwork

Ruby Developer

Upwork • Freelance

Apr 2020 - Oct 2020 • 6 mos

Supported and developed new features for a domain-driven quiz application called 'What? Where? When?'. Enhanced functionality and maintained high code quality through comprehensive RSpec testing, utilizing FactoryBot for fixtures and Capybara for integration tests.

Ruby Engineer

Company • Full-time

Feb 2020 - May 2020 • 3 mos

Remote Greenhouse Management App – Sole developer responsible for the operational integrity of an application monitoring and controlling temperature and environmental indicators in remote greenhouses. Designed, implemented, and maintained core features ensuring real‑time data accuracy and reliability. Stack: Ruby, Rails, MySQL Libs: Devise, RSpec Advertising App for Promotion – Backend developer in an 11‑member team, delivering new features and resolving bugs to enhance platform performance and stability. Stack: Ruby, Rails, PostgreSQL Libs: CanCan, Devise, RSpec, Capybara, Cucumber