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I’m a senior full-stack engineer with 10+ years of experience building production Ruby on Rails and React products, from architecture and API design to background jobs, testing, and deployment. I enjoy founder-style ownership—turning business requirements into scalable systems, shipping end-to-end, and iterating quickly based on real feedback. My work spans PropTech SaaS and complex interactive UIs: Rails/React GraphQL services, PostgreSQL data modeling and reporting, Sidekiq/Redis processing, and AWS/Linux delivery with CI/CD automation. I also bring hands-on product thinking from independent builds, including editor-like interfaces and AI-assisted workflows, collaborating closely with stakeholders to diagnose issues, improve performance, and deliver reliable features.…I’m a senior full-stack engineer with 10+ years of experience building production Ruby on Rails and React products, from architecture and API design to background jobs, testing, and deployment. I enjoy founder-style ownership—turning business requirements into scalable systems, shipping end-to-end, and iterating quickly based on real feedback. My work spans PropTech SaaS and complex interactive UIs: Rails/React GraphQL services, PostgreSQL data modeling and reporting, Sidekiq/Redis processing, and AWS/Linux delivery with CI/CD automation. I also bring hands-on product thinking from independent builds, including editor-like interfaces and AI-assisted workflows, collaborating closely with stakeholders to diagnose issues, improve performance, and deliver reliable features.

Vadym Kalion

Full Stack Developer, Web Developer, Software Engineer, +2

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I’m a senior full-stack engineer with 10+ years of experience building production Ruby on Rails and React products, from architecture and API design to background jobs, testing, and deployment. I enjoy founder-style ownership—turning business requirements into scalable systems, shipping end-to-end, and iterating quickly based on real feedback. My work spans PropTech SaaS and complex interactive UIs: Rails/React GraphQL services, PostgreSQL data modeling and reporting, Sidekiq/Redis processing, and AWS/Linux delivery with CI/CD automation. I also bring hands-on product thinking from independent builds, including editor-like interfaces and AI-assisted workflows, collaborating closely with stakeholders to diagnose issues, improve performance, and deliver reliable features.…I’m a senior full-stack engineer with 10+ years of experience building production Ruby on Rails and React products, from architecture and API design to background jobs, testing, and deployment. I enjoy founder-style ownership—turning business requirements into scalable systems, shipping end-to-end, and iterating quickly based on real feedback. My work spans PropTech SaaS and complex interactive UIs: Rails/React GraphQL services, PostgreSQL data modeling and reporting, Sidekiq/Redis processing, and AWS/Linux delivery with CI/CD automation. I also bring hands-on product thinking from independent builds, including editor-like interfaces and AI-assisted workflows, collaborating closely with stakeholders to diagnose issues, improve performance, and deliver reliable features.

Available to hire

I’m a senior full-stack engineer with 10+ years of experience building production Ruby on Rails and React products, from architecture and API design to background jobs, testing, and deployment. I enjoy founder-style ownership—turning business requirements into scalable systems, shipping end-to-end, and iterating quickly based on real feedback.

My work spans PropTech SaaS and complex interactive UIs: Rails/React GraphQL services, PostgreSQL data modeling and reporting, Sidekiq/Redis processing, and AWS/Linux delivery with CI/CD automation. I also bring hands-on product thinking from independent builds, including editor-like interfaces and AI-assisted workflows, collaborating closely with stakeholders to diagnose issues, improve performance, and deliver reliable features.

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Work Experience

Senior Full-Stack Engineer at SVITLA SYSTEMS

September 1, 2022 - June 1, 2026

Delivered production features across Ruby on Rails, React, Node.js, GraphQL, Snowflake, and integration layers for large-scale PropTech/SaaS products tied to RealPage/Knock/LOFT. Contributed across frontend, backend, data, and integration workflows; participated in architecture, technical design, estimation, code reviews, and testing/CI/CD improvements. Worked on Rails services, GraphQL APIs, OAuth/SAML-related functionality, and Kafka-related support. Debugged production issues involving SQL/data access, integrations, performance bottlenecks, and application behavior.

Senior Full-Stack Engineer at SVITLA SYSTEMS

October 1, 2015 - September 1, 2022

Designed and developed Ruby on Rails backend services and REST APIs, including reporting systems and billing workflows, supporting cloud-based business applications. Built data-driven functionality and operational workflows using Rails with PostgreSQL-oriented systems and frontend/backend integration patterns. Participated in architecture and technical design decisions to translate business requirements into scalable, maintainable solutions. Collaborated with product/engineering stakeholders on workflow automation, reporting, and business-process functionality; supported implementation planning, code reviews, and continuous improvements of engineering practices.

Ruby on Rails Developer at 5GATES

January 1, 2014 - December 31, 2015

Led architecture and backend/frontend development of an AWS-hosted travel marketplace using Ruby on Rails. Designed scalable backend services, integrations, and internal marketplace workflows. Customized ActiveAdmin UI and internal business workflows. Integrated Stripe for payments/billing and supported AWS-hosted application delivery. Owned architecture, Rails backend, frontend implementation, and product delivery in a fast-moving environment.

CTO / Senior Software Engineer at APPSMAKERSTORE.COM

January 1, 2012 - December 31, 2014

Managed and mentored a 5-person engineering team building a white-label mobile application platform. Led system architecture, development processes, and delivery for a SaaS/platform product with backend and frontend guidance. Coordinated engineering across backend, frontend, platform functionality, and integrations. Built and supported SaaS functionality including Stripe checkout, subscriptions, invoices, refunds, and OpenID Connect integration. Supported deployment and production operations using Heroku, AWS, Capistrano, New Relic, Datadog, and related operational tooling.