Olexii Kasianenko — Ruby Full-Stack Engineer

Expertise in Full Stack Web (10.0 yr.), Back-End Web (10.0 yr.).

Last verified on June, 2026

Core Skills

Bio Summary

Over 10 years of expertise in Ruby on Rails and PostgreSQL, specializing in scalable web applications and performance optimization.
Proven track record in designing modular microservices and implementing automated KYC systems, enhancing verification success, and reducing manual workload.
Extensive experience with Angular (5+ years) and React for full-stack development, delivering high-traffic social networks and CRM platforms.
Skilled in REST/GraphQL APIs, real-time high-concurrency backend architectures, and cloud technologies including AWS and Docker.

Technical Skills

Programming Languages	JavaScript, Ruby, TypeScript
JavaScript Frameworks	Angular, React
Ruby Frameworks	Ruby on Rails, Sinatra
Databases & Management Systems / ORM	MySQL, PostgreSQL
Cloud Platforms, Services & Computing	AWS
Virtualization, Containers and Orchestration	Docker
Version Control	Git
SDK / API and Integrations	GraphQL, RESTful API
QA, Test Automation, Security	RSpec

Work Experience

Ruby Engineer - DIDWW (Modular CRM platform and automated KYC verification system)

Duration: 2022 – Present

Summary:

Designed and developed a modular CRM platform using three interconnected Ruby on Rails microservices for telecom communication management
Implemented an automated KYC verification system to improve verification success rates and reduce manual review workload, enhancing backend reliability and performance of customer-facing services

Responsibilities:

Designed and developed a modular CRM platform microservices architecture.
Implemented an automated KYC verification system.
Enhanced backend reliability, performance, and maintainability.
Collaborated with product managers, QA engineers, and stakeholders in an international Agile environment.

Technologies: Ruby on Rails, PostgreSQL, REST APIs, AWS

Ruby Engineer - Anadea Inc (Dutch e-commerce platform and German educational platform)

Duration: 2021 – 2022

Summary:

Maintained and optimized a large-scale Dutch e-commerce platform by improving backend and database performance
Extended and supported a German educational platform by adding new features and stability fixes while working directly with European clients in distributed, cross-functional teams

Responsibilities:

Maintained and optimized the backend and database of a Dutch e-commerce platform.
Delivered performance enhancements, reducing response times.
An extended and supported German educational platform with new features and fixes.
Collaborated with European clients in distributed teams.

Technologies: Ruby on Rails, PostgreSQL, JavaScript

Full-Stack Engineer - Minichat.com (Minichat.com social network platform)

Duration: 2015 – 2021

Summary:

Built and maintained a high-traffic social network platform with a Ruby (Sinatra) backend and Angular frontend
Developed internal content management and moderation tools, optimized PostgreSQL queries to reduce API latency, integrated a face recognition module to decrease manual moderation time, and architected backend services for real-time, high-concurrency workflows

Responsibilities:

Developed and maintained the backend and frontend of a social network platform.
Created internal content management and moderation tools.
Optimized PostgreSQL queries and indexing to reduce API latency.
Integrated face recognition module to improve moderation efficiency.
Architected backend services for reliable real-time, high-concurrency workflows.

Technologies: Ruby, Sinatra, Angular, PostgreSQL, REST APIs

Education

Master’s Degree in Computer Systems and Networks
Kryvyi Rih National University
2006–2011

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