We are looking for a senior Ruby on Rails developer to help us build reliable, scalable products and apply AI/LLM technologies where they create real value. This is a hands-on engineering role for someone who can own complex features end to end, make strong technical decisions, and work across backend architecture, production systems, testing, and AI-assisted product development. You should be excited about AI, but pragmatic enough to know when a simple, deterministic solution is better than an LLM call. ### What you’ll be working on: - Owning features from technical design to production - Building and maintaining Ruby on Rails systems used at scale - Designing AI/LLM-assisted features and workflows where they improve product quality or user experience - Working with LLM APIs, prompts, retrieval/context strategies, and AI-assisted development tools - Making trade-offs around performance, reliability, cost, latency, security, and maintainability - Writing and maintaining automated tests, including unit, integration, and E2E tests - Debugging production issues and improving system reliability ### What we’re looking for: To succeed in this role, you’ll have: - Strong professional experience with Ruby on Rails, ideally at senior level - Experience building and running production systems used by real customers - Strong backend skills, including databases, API design, performance, background jobs, and security; - Ability to break down ambiguous problems and propose practical technical solutions - Hands-on interest or experience with AI/LLM technologies, - Good judgment about when to use AI and when simpler engineering approaches are better - Strong testing habits and care for long-term code quality - A responsible, curious, flexible mindset: willing to debug, deploy, investigate, learn, and own outcomes **Nice to have:** - Experience with React - CI/CD, background jobs, or AWS experience - Experience building AI-powered product features in production - Familiarity with embeddings, vector search, RAG, evals, or LLM observability - Experience with text-processing, localization, translation, or multilingual products ### Why Join [OTGS](https://onthegosystems.com/)? - Stable & self-funded: Founded in 2007, profitable, and independent. - Industry leaders: Creators of [WPML](https://wpml.org/), the #1 multilingual plugin for WordPress, used on 1.5M+ sites - Fully remote, async-friendly: Work from anywhere within EMEA hours - Engineering-driven culture: Ownership, autonomy, testing, and thoughtful problem-solving - Fair compensation and great benefits: Designed to support your well-being both inside and outside of work.