Senior Ruby on Rails Developer (AI-Augmented Engineering)

Headquarters: Sweden URL: http://career.proxify.io The Role: We are seeking a Senior Ruby on Rails Developer who treats software engineering as an art form and a discipline. In this role, you will lead the development and scaling of highly responsive, business-critical web applications. You won't just build features; you will optimize system architectures, manage complex domain models, and champion engineering practices that keep codebases sustainable over long lifecycles. We look for developers who understand the core principles of software craftsmanship and can leverage modern technologies—like AI development workflows—to compress delivery timelines without compromising code quality. If you are an active contributor to the broader tech community and are obsessed with writing clean, expressive Ruby, you will thrive here. What we are looking for: 5+ years of production experience writing object-oriented Ruby and scaling robust Rails applications. Strong command over architectural patterns, domain-driven design, data modeling, concurrency, caching strategies, and API security protocols. You value automated testing (RSpec/Minitest) as a critical design tool. Proven ability to integrate AI development tools (such as GitHub Copilot, Cursor, or specialized LLM agents) into your daily engineering workflow. We value engineers who use AI to accelerate boilerplate writing, refactoring, and test generation, while maintaining the critical eye needed to debug and validate the outputs. A history of interacting with or contributing directly to the open-source community—whether that means maintaining custom gems, submitting PRs to public repositories, or actively contributing to the Rails ecosystem. Hands-on experience optimizing PostgreSQL databases, managing background processing via Sidekiq, and deploying containers with Docker into cloud native environments (AWS/GCP/Heroku). Located in CET timezone (+/- 3 hours), we are unable to consider applications from candidates in other time zones. Responsibilities: Design and maintain modular, testable, and highly performant backend architectures that support complex business domains. Pioneer the adoption of AI-assisted coding practices within the team, demonstrating how to use modern generative tools to double execution speed safely. Identify and eliminate N+1 queries, tune database indexes, and optimize memory consumption to ensure low-latency application responses. Conduct meaningful code reviews that elevate the team's engineering bar, ensuring adherence to the Ruby Style Guide and SOLID design principles. Bring public open-source best practices into our private repositories, keeping our internal tools modern, secure, and maintainable. What we offer: Get paid, not played No more unreliable clients. Enjoy on-time monthly payments with flexible withdrawal options. Predictable project hours Enjoy a harmonious work-life balance with consistent 8-hour working days with clients. Flex days, so you can recharge Enjoy up to 24 flex days off per year without losing pay, for full-time positions found through Proxify. Career-accelerating positions at cutting-edge companies Discover exclusive long-term remote positions at the world's most exciting companies. Hand-picked opportunities, just for you Skip the typical recruitment roadblocks and biases with personally matched positions. One seamless process, multiple opportunities A one-time contracting process for endless opportunities, with no extra assessments. Compensation Enjoy the same pay, every month with positions landed through Proxify. To apply: https://weworkremotely.com/remote-jobs/proxify-ab-senior-ruby-on-rails-developer-ai-augmented-engineering