Senior Ruby on Rails / Full Stack Engineer with 10+ years of experience building and scaling revenue-critical SaaS platforms for US-based companies. Specialized in billing, subscriptions, invoicing, and payment workflows, working extensively with Stripe, Chargebee, and Salesforce, where correctness, performance, and reliability directly impact revenue and customer trust. Backend-heavy engineer with strong full-stack ownership, delivering end-to-end features including data modeling, API/GraphQL design, background jobs, performance optimization, frontend development with React and TypeScript, automated testing, and production releases. Experienced working in high-traffic, multi-tenant SaaS systems and collaborating remotely with distributed, English-speaking teams. Core strengths: Ruby on Rails, PostgreSQL, SaaS architecture & system design, billing & subscription systems, Stripe, Chargebee, Salesforce, performance optimization, background jobs, RSpec, Cypress, AWS.