Product AI Engineer

Job title: Product AI Engineer

About the Role As a Product AI Engineer at Factorial, you’ll help define and build the next generation of our AI-native product using modern AI development practices. You’ll work at the intersection of product and platform, shaping AI-powered workflows and integrations to deliver real impact for customers.

What You'll Do

• Build product using Spec Driven Development. We define clear specifications before shipping — including expected behaviours, constraints, and success criteria — and use them to guide implementation, iteration and evaluation using most powerful LLMs.
• Design and implement AI Skills: Create reusable, well-scoped AI capabilities that can automate and take actions safely within Factorial’s workflows, and also when building integrations.
• Develop and maintain evaluation frameworks (Evals): Measure quality, correctness and reliability of AI outputs using automated and human-in-the-loop evaluations to ensure continuous improvement in production.
• Apply Retrieval-Augmented Generation (RAG): Build systems that ground AI responses in trusted, up-to-date company data, balancing probabilistic models with deterministic sources of truth.
• Design human-in-the-loop and agentic workflows: Combine LLMs, rules, and user oversight to automate real business processes while keeping humans in control of critical decisions.
• Own systems end-to-end: From problem definition and system design to shipping, monitoring and iteration in production.
• Stay close to our customers: Engineers regularly join customer calls, reviews, and feedback sessions to deeply understand real workflows, pain points, and constraints — ensuring we build the right solutions to real problems, not assumptions.
• Collaborate closely with Product and Design: Shape how AI is embedded into core user experiences — not as a feature, but as part of the workflow.
• Share knowledge and raise the bar: Mentor peers, document learnings, and contribute to Factorial’s AI engineering best practices.

What We're Looking For

• Your title matters less than your mindset. You might be mid, senior, or staff. What we care about is AI as a habit: you’ve built real AI-powered systems or workflows (not just experiments).
• Proven impact: shipped projects, side projects, or contributions that made a measurable difference.
• Product-first thinking: you design complete experiences, not just isolated components.
• Speed & adaptability: you experiment, learn, and iterate fast.
• Bonus points if you’ve worked with: LLMs, skill-based agents, MCP, or other AI protocols.
• Technical Foundation (Not Strict Requirements): Solid software engineering fundamentals (any language — backend, frontend, ML); Experience shipping real products to production; Knowledge of APIs, cloud platforms, and system design; A fast learning curve with new tools and technologies.
• We care far more about what you’ve built than the stack you used.

Nice to Have

• LLMs, skill-based agents, MCP, or other AI protocols (bonus points)

Compensation & Benefits

• Salary: Not disclosed
• Office-first in A Coruña, with 20% remote flexibility; inclusive, diverse culture; 1,200+ employees across 7 markets; support for growth and learning.