Senior Ruby on Rails Engineer (LLM)

Posted 3 Days Ago
Be an Early Applicant
Hiring Remotely in Spain
Remote
Senior level
Artificial Intelligence • Machine Learning • Natural Language Processing • Software
The Role
Own end-to-end features on Ruby on Rails systems at scale, design and implement AI/LLM-assisted workflows, work with LLM APIs and retrieval strategies, ensure performance, reliability, and security, write automated tests, debug production issues, and maintain long-term code quality.
Summary Generated by Built In

Senior Ruby on Rails Engineer 

We are looking for a Senior Ruby on Rails Engineer 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?
  • 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.

Want to make a lasting impact on a product used by thousands of real customers? We would love to hear from you.


 

Skills Required

  • Strong professional experience with Ruby on Rails
  • Experience building and running production systems used by real customers
  • Strong backend skills (databases, API design, performance, background jobs, security)
  • Hands-on interest or experience with AI/LLM technologies and LLM APIs
  • Ability to break down ambiguous problems and propose practical technical solutions
  • Writing and maintaining automated tests (unit, integration, E2E)
  • Good judgment about when to use AI vs simpler engineering approaches
  • Responsible, curious, flexible mindset; willing to debug, deploy, investigate, learn, and own outcomes
  • Experience with React
  • CI/CD or AWS experience
  • Experience building AI-powered product features in production; familiarity with embeddings, vector search, RAG, or LLM observability
  • Experience with text-processing, localization, translation, or multilingual products
Am I A Good Fit?
beta
Get Personalized Job Insights.
Our AI-powered fit analysis compares your resume with a job listing so you know if your skills & experience align.

The Company
110 Employees
Year Founded: 2007

What We Do

OnTheGoSystems is a fully remote software development company specializing in localization and translation tools, including the popular WordPress plugins WPML and Toolset. The company harnesses AI, machine learning, and algorithms to create affordable, cutting-edge tools that help businesses of all sizes go global. Operating as a multilingual and multicultural team, it focuses on providing intuitive solutions for developers and website owners without relying on external investors.

Similar Jobs

Nexthink Logo Nexthink

Finance Director (FP&A)

Artificial Intelligence • Big Data • Cloud • Information Technology • Machine Learning • Software
Remote or Hybrid
Madrid, Comunidad de Madrid, ESP
1200 Employees
85K-125K Annually

Dynatrace Logo Dynatrace

Senior Analytics Engineer

Artificial Intelligence • Big Data • Cloud • Information Technology • Software • Big Data Analytics • Automation
Remote or Hybrid
Barcelona, Cataluña, ESP
5600 Employees

Cloudflare Logo Cloudflare

Account Executive

Cloud • Information Technology • Security • Software • Cybersecurity
Remote or Hybrid
Spain
4400 Employees

Datadog Logo Datadog

Senior Software Engineer

Artificial Intelligence • Cloud • Security • Software • Cybersecurity
Easy Apply
Remote or Hybrid
10 Locations
6500 Employees

Similar Companies Hiring

Hanover Park Thumbnail
Artificial Intelligence • Fintech • Software • Financial Services
New York, New York
42 Employees
Kepler  Thumbnail
Fintech • Software
New York, New York
6 Employees
Onshore Thumbnail
Artificial Intelligence • Fintech • Software • Financial Services
New York, New York
60 Employees

Sign up now Access later

Create Free Account

Please log in or sign up to report this job.

Create Free Account