Denis G. Ruby on Rails Engineer / Architect

Back-End Web

Summary

- Senior Software Developer & Architect with 14+ years of experience designing scalable software solutions, leading teams, and optimizing system performance.
- Expertise in Ruby, JavaScript, and cloud-based architectures (AWS, DigitalOcean, Docker).
- Specializing in e-commerce platforms, payment systems integration, microservices architecture, search optimization, and IoT device integration, including video streaming and motion detection algorithms.
- Passionate about architecting high-performance applications, integrating IoT solutions, AI technologies,
and leading cross-functional engineering teams to drive innovation and scalability.

Experience

Senior Software Developer / Team Lead / Architect

JULY 2018 - PRESENT

  • Developed and maintained a hospital schedule management platform for UKG.
  • Designed and built an e-commerce platform from scratch, serving as the Team Lead, managing a cross-functional team, and overseeing the architecture, development, and deployment processes.
  • Implemented a goods recommendation system based on customer survey responses.
  • Integrated Stripe and multiple third-party platforms for logistics, email campaigns, and gift cards.
  • Connected an Elixir-based microservice with a Rails app to handle ElasticSearch data.
  • Worked with IoT devices, including CCTV, security systems, and GPS trackers for bikes and pets.
  • Optimized live camera streaming, improving resolution & latency.
  • Worked on algorithms and logic for detecting motion in camera feeds.

Senior Ruby Developer, Excelerators

DECEMBER 2017 - JUNE 2018

  • Identified and resolved service performance issues to enhance efficiency and scalability.
  • Designed and implemented search functionality supporting multiple parameters for accurate and efficient results.
  • Developed and optimized a sophisticated booking process to improve user experience and reliability.
  • Collaborated with the product owner to gather requirements, provide updates, and ensure alignment with business goals.

Middle/Senior Ruby Developer, Svitla Systems

FEBRUARY 2014 - DECEMBER 2017

  • Developed integration modules for Slack, Salesforce (worked with Apex), SharePoint, and various internal services.
  • Forked the sharepoint-ruby gem, adding support for webhooks and Office 365 Video Hub.
  • Implemented face detection, recognition, photo cropping, and social media sharing (Facebook, Twitter, Instagram).
  • Developed scripts for migrating data from MS SQL to PostgreSQL and optimized search functionality using ElasticSearch.
  • Migrated frontend design from Foundation and custom styles to Bootstrap.

Junior Ruby Developer, Interlink LLC

SEPTEMBER 2010 - FEBRUARY 2014

  • Implemented design features, including sticky notes, checklists, WYSIWYG editing, canvas splitting, workspace switching, and image uploading in MeteorJS-based system.
  • Integrated PayPal payment gateway.
  • Developed a system for employee screening, testing, and hiring, allowing companies to create vacancies and custom questionnaires (text, multiple choice, video, and file-based questions).
  • Designed and implemented a system where each company had a dedicated site (subdomain or personal domain) fetching data from a central hub via REST API.
  • Built a Ruby-based server using sockets to manage Linux Apache and BIND configurations dynamically.
  • Implemented functionality to sync data between multiple sites for consistency and reliability.

Education 

Cherkasy State Technological University

B.S. Software Engineering (2009 - 2011)