Staff Software Engineer — AI-Driven Features

Creandum; La Coruña; On-site; EUR 94,000 - 119,000; Full time

Job summary

Factorial is seeking a Staff Software Engineer to help build AI-native features into our product. You’ll lead technical initiatives, collaborate closely with Product and Design, and own end-to-end systems from inception to production.

You’ll write Rails and React, design scalable architectures, and ship real features to customers in production. As a Staff Engineer, you’ll influence the roadmap, drive integration of LLM APIs, and push for reusable components across teams.

Qualifications

• Solid depth in backend and frontend software engineering.
• Shipped real products to production, not just prototypes or proofs of concept.
• Understand APIs, cloud platforms (AWS, Azure, or GCP), and system design well.
• Integrated LLM APIs into product features and shipped them to real users.
• You’re seen as a technical and cultural leader with high standards.
• Push back on processes that don’t serve the team and drive adoption of new abstractions.
• You lead key technical decisions and create reusable components across teams.
• Clear English communication; Spanish is a plus.

Responsibilities

• Lead technical initiatives and set architectural direction for meaningful roadmap areas.
• Collaborate closely with Product and Design from early conversations to implementation.
• Own systems end-to-end from inception to production and maintenance.
• Engage with customers to bring real context into product decisions.
• Help define how to build AI features at scale that are reliable and compliant.
• Promote spec-driven development with clear success criteria.
• Build reusable components and tooling that other teams can use.
• Design and evolve AI skills that automate workflows within Factorial.

Skills

Backend & frontend depth

Production experience

APIs & Cloud

LLM API integration

Leadership & culture

System design

English communication

Tools

Ruby on Rails

React

Job description

Factorial is seeking a Staff Software Engineer to help build AI-native features into our product. You’ll lead technical initiatives, collaborate closely with Product and Design, and own end-to-end systems from inception to production.

You’ll write Rails and React, design scalable architectures, and ship real features to customers in production. As a Staff Engineer, you’ll influence the roadmap, drive integration of LLM APIs, and push for reusable components across teams.