Senior Full Stack Engineer (Ruby + React)

About the Position

We are looking for a Senior Full Stack Engineer (Ruby + React) to develop and scale a multi-tenant SaaS platform that delivers real estate and asset-management data at scale. You will contribute across the full stack - from PostgreSQL query tuning and background data pipelines to server-rendered Hotwire views and interactive React + TypeScript front-end components - and take ownership of features end-to-end, from specification through production release on AWS-backed Kubernetes.

This is a hands-on engineering position within a team that prioritizes strong test coverage, clean conventions, and delivering dependable software to a demanding production environment.

Responsibilities

• Design and implement features across a Ruby on Rails 8 monolith using proven patterns: form objects, query objects, service objects, Pundit policies, and ViewComponents
• Build dynamic, server-rendered UI with Hotwire (Turbo + Stimulus) and Bootstrap 5, along with richer interactive interfaces via React + TypeScript (MUI, ag-grid, react-select, chart.js) bundled through Vite
• Model and optimize data in PostgreSQL - craft efficient queries, design indexes, remove N+1s, and author safe, zero-downtime migrations
• Implement asynchronous and scheduled work with Sidekiq - including data ingestion pipelines, file processing, and long-running jobs
• Write thorough automated tests (RSpec request/system specs, Vitest) as a standard element of every change
• Deliver code through a CI/CD pipeline that builds Docker images, pushes to AWS ECR, and deploys to Kubernetes clusters across staging and production
• Collaborate on infrastructure managed via Terraform and Kubernetes manifests stored in dedicated infrastructure repositories

Requirements

• 5+ years of professional software development experience
• 3+ years building production applications with Ruby on Rails, including a solid grasp of Rails conventions, ActiveRecord, and background processing with Sidekiq
• Proficiency in PostgreSQL - crafting efficient queries and reasoning about indexes and schema changes
• Expertise in React and TypeScript on the front end, and openness to working in a server-rendered Hotwire (Turbo/Stimulus) environment
• Familiarity with authentication and authorization patterns (e.g., Auth0, OmniAuth, Warden, Pundit, or similar tools)
• A test-first mindset; capability to write meaningful tests and validate behavior rather than assuming it
• Excellent command of written and spoken English (B2+ level)

Nice to Have

• Deeper proficiency in PostgreSQL - covering query tuning, indexing strategy, connection pooling, and safe zero-downtime migrations
• Knowledge of AWS services (ECR, S3, RDS) along with deploying containerized applications to Kubernetes
• Background in Terraform and infrastructure-as-code workflows, particularly when app and infra reside in separate repositories
• Understanding of multi-tenant architectures (subdomain-based tenancy) plus exposure to data-pipeline / ETL work, file ingestion (S3 multipart, SFTP), and document/spreadsheet processing
• Skills in observability tooling (Sentry, New Relic, Prometheus) together with production hardening (rate limiting, secure headers, health checks)

We Offer

• Opportunity to work remotely from Ukraine
• Engaging in a challenging and impactful role within a leading tech company

About the Company

EPAM Systems is a global software engineering and product development company with a focus on delivering innovative solutions to clients across various industries. Our team is dedicated to creating high-quality software that meets the evolving needs of our clients and users.