Build and extend a large Rails 8 application supporting a high-traffic website, CMS, integrations, APIs, and mobile consumers. Develop Hotwire and Stimulus interfaces, design resilient Sidekiq workflows and third-party integrations, optimize PostgreSQL and application performance, implement caching and scalability improvements, address security issues, and write automated tests. Collaborate with editorial, marketing, mobile, and distributed engineering teams while improving accessibility, observability, and reliability.