Provide senior-level technical and production support for a large Ruby on Rails application. Troubleshoot application, database, hosting, API, payment, and integration issues across Ruby on Rails, PostgreSQL, Heroku, Stripe, and AWS S3. Perform root cause analysis, incident resolution, debugging, SQL queries, scripts, configuration changes, and code fixes. Collaborate with Engineering, Product, QA, and Customer Support while maintaining documentation, runbooks, and RCA reports. Night-shift availability is required.