Ruby Developer

Senior Ruby on Rails Developer I’m working with a fast-growing, well-invested SaaS company that is looking for a Senior Ruby on Rails Developer to join its engineering team. The company provides a global SaaS platform used by more than 65,000 people across the UK, Europe, the US and APAC, helping organisations manage information security, privacy and regulatory compliance. This is a senior individual contributor role with real ownership and influence. You will work closely with the Tech Lead to build new features, improve architecture, modernise a mature Ruby on Rails platform and contribute ideas across engineering. The core product is a long-running Rails monolith with over 15 years of history. Some legacy patterns still exist, but new development is moving in a clear modern direction. This role would suit someone who is comfortable working across both legacy and modern Rails code, can make pragmatic technical decisions, and enjoys improving systems over time rather than wanting to rewrite everything from scratch. You will be joining a small, capable engineering team where your input will genuinely matter. What You’ll Be Doing * Building and maintaining product features in Ruby on Rails * Working across legacy and modern areas of the application * Contributing to architecture decisions and platform improvements * Improving performance, maintainability and developer productivity * Supporting code reviews, pairing, technical planning and mentoring * Helping the team use AI tools in a practical, sensible way * Contributing ideas, not just completing tickets Tech Stack The core stack includes Ruby on Rails, Ruby, MySQL, GitHub Actions, Cypress, Turbo, StimulusJS, Action Policy, RailsEventStore, DelayJob, New Relic, JIRA and Confluence. The engineering roadmap includes moving ERB toward Phlex, Solr toward ElasticSearch or OpenSearch, improving component separation and continuing to modernise the platform in a pragmatic way. AI in Engineering The company is actively exploring how AI can improve engineering productivity, quality and workflow. They are not looking for an AI specialist or machine learning engineer. They are looking for a strong Rails developer who is already using, or genuinely interested in using, tools such as GitHub Copilot, Claude Code, OpenAI Codex or similar to support coding, refactoring, testing, documentation and workflow improvement. You should have good judgement about where AI helps, where it does not, and how to use it without losing proper engineering discipline. What We’re Looking For * Strong commercial Ruby on Rails experience * Solid Ruby fundamentals and object-oriented design skills * Experience working with mature or legacy codebases * Strong SQL skills * Testing experience across unit, integration and end-to-end levels * Ability to contribute to architecture and technical direction * High autonomy and initiative * Strong communication skills * Product awareness and a pragmatic approach to engineering * A positive, thoughtful approach to AI-assisted development You do not need to tick every box, but you should be comfortable operating independently and contributing as a senior member of a small engineering team. Useful Experience Any of the following would be beneficial, but not essential: * Stimulus, Turbo or Hotwire * Event-driven architecture * Security, compliance or governance software * ISO 27001 or similar standards * AI-assisted development workflows * Automation, agentic workflows or AI evaluation Salary & Working Pattern * Remote-first UK role * Occasional company days in Brighton (Voluntary and Expensed) * Full-time, permanent position This is a great opportunity to join a growing SaaS business where you can have real influence, work on meaningful product challenges and help modernise an established Rails platform