Location: Cherkasy, Ukraine
Remote: Yes (remote only, EU hours, US-East overlap OK)
Willing to relocate: No
Technologies: Ruby on Rails (8+ yrs), PostgreSQL, Redis, Sidekiq, Elasticsearch, Stripe/PayPal/webhooks, React/Next.js/TypeScript, AWS (SQS/S3), Claude Code + Cursor (custom skills, multi-agent review pipelines)
Résumé/CV: on request
Email: leonidfilbert@gmail.com
Senior backend engineer, payments is my specialty. I own billing on a production SaaS subscription marketplace: 21 Stripe + 4 PayPal webhook event types across 29 idempotent handler commands, recurring billing, retries, reconciliation, a seller-earnings ledger. Shipped LLM features to production (NL search, SQS-decoupled, WebSocket streaming). I work AI-augmented daily: custom Claude Code skills and a multi-agent code review pipeline I built for our codebase. Looking for a senior backend/full-stack role at a product company. B2B contractor (own entity), no sponsorship needed, available immediately.
Senior backend engineer, payments is my specialty. I own billing on a production SaaS subscription marketplace: 21 Stripe + 4 PayPal webhook event types across 29 idempotent handler commands, recurring billing, retries, reconciliation, a seller-earnings ledger. Shipped LLM features to production (NL search, SQS-decoupled, WebSocket streaming). I work AI-augmented daily: custom Claude Code skills and a multi-agent code review pipeline I built for our codebase. Looking for a senior backend/full-stack role at a product company. B2B contractor (own entity), no sponsorship needed, available immediately.