Staff Software Engineer

Hello!

We're looking for a Staff Software Engineer to help build AI-native features into Factorial's product. Not a researcher, not a model trainer: a product engineer who builds with LLM APIs the same way we build with any other API, shipping real features to real customers in production.

At Factorial, being a Staff Engineer means leading technical initiatives and working very closely with Product, not operating at arm's length from the roadmap. You'll be writing Rails and React, designing systems, and shipping product hand in hand with Product and Design. "AI" is the domain you'll work in, not a different job.

Ready to be part of the challenge? 🚀

About the Position

We're looking for a Staff Software Engineer to help build AI-native features into Factorial's product. You'll be leading technical initiatives, working closely with Product, and shipping real features to real customers in production.

About the Team 👥

Our Engineering team is the engine behind Factorial, crafting the tech that makes HR simple, fast, and reliable for thousands of companies. We're a team of 200+ Product Engineers building a Business Management solution that actually works for the people using it. Our core stack is Ruby on Rails and React but the interesting work right now is what we're building on top of that: agentic workflows, LLM-integrated features, systems that behave probabilistically rather than deterministically.

Responsibilities

• Lead technical initiatives. Set technical direction for meaningful chunks of the roadmap, make architecture and approach decisions, and be accountable for their outcomes.
• Work closely with Product. Shape what gets built alongside Product and Design from the earliest conversations.
• Own systems end to end. From the first conversation about a problem, through production rollout, to long-term maintenance.
• Stay close to customers. Understand real problems by talking to customers directly and bring that context back into how we build.
• Help define how we build AI features at scale. Shape how we design, build, and run AI-native product experiences so they're reliable, compliant, and genuinely useful.
• Champion spec-driven development. Push for a culture where teams define what "good" looks like before they build.
• Build things other teams can reuse. Create shared components other product domains can actually use.
• Design and evolve AI Skills. Drive the creation of modular, reusable AI "skills" that automate real workflows.
• Build the tooling that keeps AI features trustworthy. Create monitoring and quality tooling to ensure reliability.
• Ground AI features in data we actually trust. Combine LLM outputs with deterministic sources of truth, balancing flexibility with accuracy and compliance.
• Raise the bar across the company: Whether it's mentoring, hiring, or pushing for better practices, you'll leave the engineering culture better than you found it.

Requirements

• Solid depth in both backend and frontend software engineering
• Experience shipping real products to production
• Strong understanding of APIs, cloud platforms (AWS, Azure, or GCP), and system design
• Experience integrating LLM APIs into product features
• Technical and cultural leadership
• Ability to push back on process that doesn't serve the team
• Drive adoption of new abstractions and ensure others can use them
• Experience shipping things that made a measurable difference
• Ability to lead key technical decisions and create things others across the company build on
• Clear communication in English; Spanish is a plus

We Offer

• Competitive salary range: €94,300 - €118,800 Annual
• Full-time position
• Office-first, flexible schedule with on-site and remote work options
• High growth, multicultural, and friendly environment
• Competitive ESOP plan
• Alan as private health insurance
• Healthy life with Wellhub (Gyms, pools, outdoor classes)
• Save expenses with Cobee
• Language classes
• Breakfast in the office and organic fruit
• Food discounts with Nora
• Pet Friendly
• And much more that we'll share during the interview process!

About the Company

Factorial is the AI for Business that knows companies, connects how work happens across the business, and turns that context into action. Founded in Barcelona in 2016, we now have +1,700 employees serving more than 16,000 companies across 112 countries.

Factorial started with a simple idea: companies were spending too much time managing processes and not enough time doing the work they were hired to do: their best work.

But as companies grow, work gets more disconnected. More people, more tools, more information, and more time spent connecting the dots. Generic AI can answer questions, but it doesn’t know your company. Every time, you have to give it the context.

Factorial is different. Because it’s inside the company, it already knows how it works, including its people, processes, policies, and data. So you can ask it to do real work, from screening candidates and managing expenses to answering questions and creating reports.

AI isn’t the goal. Giving people back their time is.

When work changes, so do we.

We believe in diverse talent: we welcome applicants from all backgrounds and strongly encourage people of diverse experiences and identities to apply.

We believe in inclusion: we are committed to equal opportunities and actively promote workplace inclusion of people with disabilities. If you would like to learn more about our inclusive recruitment processes, you are welcome to indicate so optionally and we will share additional information with you.

Our Values

• We own it: We take responsibility for every project. We make decisions, not excuses.
• We learn and teach: We're dedicated to learning something new every day and, above all, share it.
• We partner: Every decision is a team decision. We trust each other.
• We grow fast: We act fast. We think that the worst mistake is not learning from them.

Wanna learn more about us? Check our website!

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