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Denis G., Ruby on Rails Engineer / Architect

Back-End Web
$45/hr
english B2 (Upper-Intermediate) English
seniority Architect/Team-lead
location Cherkasy, Ukraine UTC+02:00

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.

Hire Denis G.

Main Skills

Ruby, Ruby on Rails Engineer / Architect

Ruby

Ruby on Rails, Ruby on Rails Engineer / Architect

Ruby on Rails

JavaScript, Ruby on Rails Engineer / Architect

JavaScript

Programming Languages

Java JavaScript Python Ruby

JavaScript Frameworks

Backbone.js Express Node.js React

UI Frameworks, Libraries, and Browsers

Bootstrap Foundation

Ruby Frameworks

Hanami Ruby on Rails Sinatra

Ruby Libraries and Tools

rubocop

Salesforce Ecosystem

Salesforce Apex

JavaScript Libraries and Tools

Stimulus

Databases & Management Systems / ORM

AWS ElasticSearch MongoDB MySQL PostgreSQL Redis

Cloud Platforms, Services & Computing

AWS Azure DigitalOcean

Amazon Web Services

AWS ElasticSearch

Azure Cloud Services

Azure

Deployment, CI/CD & Administration

Ansible CircleCI Jenkins

Virtualization, Containers and Orchestration

Docker

Version Control

Github Actions

Message/Queue/Task Brokers

MQQT RabbitMQ

QA, Test Automation, Security

RSpec

Other Technical Skills

Hotwire/Turbo
ID: 002711-021203
Last Updated: 2025-04-17

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)