Overview

As a Staff Software Engineer at Factorial, you will shape AI-native features from end to end, collaborating closely with Product, Design, and Engineering to ship production-ready capabilities. You'll work with Rails and React, designing scalable systems and guiding technical direction for meaningful roadmap areas. You'll lead cross-functional initiatives to build reusable AI components and reliable, compliant product experiences.

This role offers impact across a fast-growing, mission-driven company building with LLM APIs and agentic workflows.

Compensaciones / Ventajas Alan private health insurance

Wellhub fitness benefits

Cobee expense management

Language classes

Breakfast in the office and organic fruit

Pet friendly workplace

Responsabilidades

Set technical direction for meaningful roadmap chunks and make architecture decisions

Collaborate tightly with Product and Design from the earliest planning stages

Own end-to-end systems from problem to production rollout and long-term maintenance

Engage with customers to capture real problems and feed context back into solutions

Define how to build AI features at scale, ensuring reliability and compliance

Promote spec-driven development with clear success criteria and edge-case handling





Create reusable components and abstractions usable by other teams

Design and evolve modular AI skills that automate workflows and ensure safe actions

Build monitoring and quality tooling (automatic and human-in-the-loop)

Ground AI outputs in trusted data sources, balancing flexibility and determinism

Raise engineering culture through mentoring and better practices

Avoid roles focused on model training or fine-tuning as this is product engineering with LLM APIs

Requisitos principales Solid depth in both backend and frontend software engineering

Experience shipping real products to production

Understanding of APIs, cloud platforms (AWS, Azure, or GCP), and system design

Experience integrating LLM APIs into product features and shipping to users

Proven leadership and ability to influence technical direction and culture

Ability to advocate for effective processes, hiring, and deployment practices

Experience building scalable, secure, and governable components

Clear English communication; Spanish a plus leadership cross-functional collaboration clear communication

Ruby on Rails

React

APIs and system design

📌 Staff Software Engineer (Barcelona)
🏢 Factorial Hr
📍 Barcelona