Senior Fullstack Engineer (Ruby on Rails) – Remote (Colombia/Costa Rica)

About the role

Gorilla Logic is seeking a Senior Full‑Stack Engineer to join a client‑facing product team. You will work on a high‑traffic Ruby on Rails monolith with a React front‑end, delivering features from architecture through production while integrating AI and LLM capabilities.

Key responsibilities

• Design, build, test, and ship full‑stack product features using Ruby on Rails and React.
• Extend and improve a large, established Rails monolith safely and efficiently.
• Develop performant, user‑focused React components and UI experiences.
• Own end‑to‑end features across backend, frontend, and data layers.
• Build product capabilities powered by LLMs and online AI inference, including prompting and context management.
• Create AI‑driven text generation experiences to streamline user workflows.
• Define measurable impact on conversion funnels and instrument experiments.
• Validate solutions with automated tests, AI evaluations, and tracing.
• Apply system design principles for scalable, maintainable, production‑ready code.
• Leverage AI‑assisted engineering techniques throughout the development lifecycle.
• Collaborate with product managers, designers, and engineers to shape solutions and identify technical constraints.
• Prototype and release MVPs early for feedback and iterative improvement.
• Participate in technical scoping, prioritization, and stakeholder communication.

Required profile

• Senior‑level professional software engineering experience with strong full‑stack capabilities.
• Extensive production experience in Ruby on Rails, especially within large monolithic applications.
• Proficiency navigating mature Rails codebases and legacy patterns.
• Solid experience building and maintaining React front‑ends.
• Hands‑on experience integrating AI/LLM services into production products.
• Comfortable collaborating directly with US‑based clients and cross‑functional teams.
• Product‑mindset with focus on measurable outcomes.

Required skills

• Ruby on Rails
• React
• JavaScript / TypeScript
• HTML & CSS
• RESTful APIs
• Git version control
• RSpec, Jest (or similar testing frameworks)
• AI/LLM integration and prompt engineering
• CI/CD pipelines
• Agile development methodologies