<p> <strong>Headquarters:</strong> Sweden <br /><strong>URL:</strong> <a href="http://career.proxify.io">http://career.proxify.io</a> </p> <div> <h3><strong>The Role:</strong></h3> <p> </p> <p>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.</p> <p> </p> <p>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.</p> <p> </p> <h4><strong>What we are looking for:</strong></h4> <ul> <li>5+ years of production experience writing object-oriented Ruby and scaling robust Rails applications.</li> <li>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.</li> <li>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.</li> <li>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.</li> <li>Hands-on experience optimizing PostgreSQL databases, m