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AI Engineer - Ruby on Rails

OnTheGoSystems

Barcelona, ESremote countryPosted May 29, 2026

Skills

railscicdrubyawsllm

About the role

We are looking for an engineer with practical AI/LLM experience who can build production features in Ruby on Rails.

This role is for someone who has worked with AI tools, LLM APIs, prompts, retrieval/context patterns, or AI-assisted workflows - and who also has the engineering depth to turn those ideas into reliable, tested, maintainable software.

What you’ll be working on:

Designing and building AI/LLM-assisted product features

Integrating LLM APIs into Ruby on Rails systems

Combining AI approaches with business logic, tests, fallbacks, and production safeguards

Owning features from technical design to production

Improving reliability, accuracy, consistency, latency, cost, security, and maintainability

Writing and maintaining automated tests, including unit, integration, and E2E tests

Debugging production issues and improving system behavior over time

Requirements

What we’re looking for:

To succeed in this role, you’ll have:

Practical experience building with AI/LLM technologies, not just using AI tools casually

Strong Ruby on Rails experience, ideally at a senior level

Good judgment about when AI is useful and when simpler engineering is better

Strong backend skills, including databases, API design, performance, background jobs, and security

Ability to break down ambiguous problems into clear technical solutions

Nice to have:

CI/CD, background jobs, or AWS experience

Experience with text-processing, localization, translation, or multilingual products

Benefits

Why Join OTGS?

Stable & self-funded: Founded in 2007, profitable, and independent.

Industry leaders: Creators of WPML, 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.

Questions about this role

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  • What's the typical salary for Machine Learning Engineer in Spain?

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