Senior Product Software Engineer - Operations Domain

Factorial HR; Barcelona; Híbrido; EUR 90.000 - 120.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Alan as private health insurance

Wellhub gym membership

Cobee benefits platform

Language classes

Office breakfasts

Nora discounts

Free caffeine

Descripción de la vacante

Factorial HR in Barcelona is hiring a Product Engineer to help build and scale the AI-Driven Operations Domain, supporting managers and HR teams with time management, employee lifecycle, and compensation tools.

You’ll design systems, orchestrate multi-agent workflows, and ensure outputs are secure and scalable. The role blends in-person collaboration with flexible remote work, aiming to advance cutting-edge AI features across HR ops.

Formación

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Responsabilidades

• Design architectures and write high-level prompts for multi-agent systems to generate underlying code.
• Review and validate agent outputs for security, scalability, and structure.
• Coordinate multiple AI agents running in parallel and ensure coherent output across features.
• Define workflows, experiment, and share effective practices in a fast-moving team.

Conocimientos

AI-powered features

Reliability

English communication

LLM architecture

Distributed systems

Ruby on Rails

Herramientas

Ruby on Rails

React

Descripción del empleo

Hello!

Do you want to help us redefine how AI powers the future of Business Management software, not as an add-on, but as a core part of how people work, decide and grow?

We’re looking for engineers who:

• Treat AI as central to their craft, not a feature to bolt on later
• Want to build and ship, not debate and document
• Care about whether the thing they built actually worked — not what their title says.

Ready to be part of the challenge?

At Factorial we’re looking for a Product Engineer to help us build and scale our AI- Driven Operations Domain to the next level. As part of this team, which is in charge of providing tools to managers and HR managers in the areas of recruitment, performance, engagement, and trainings, you’ll be at the forefront of developing tools and help to improve the way companies take care of their people, their most valuable asset.

Ready to be part of the challenge?

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. If you love solving hard problems and want to build something that truly matters, come build it with us.

We’re a team of 200+ Product Engineers building 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.

The Operations domain sits at the core of Factorial. This is where we build the systems that run the day-to-day reality of work for thousands of companies, systems that must be accurate, compliant and reliable.

To do this, we provide tools to managers and HR managers in the areas of time management, employee lifecycle, and compensation. But we know there is space for more! That’s why we need talented people to go faster.

What are we looking for?

• You’ve shipped AI-powered features and know that evaluating them in production is the hard part, not building them. You think about reliability and user friction before model complexity.
• You're comfortable reviewing agentic workflows and have opinions about LLM architecture tradeoffs. Not just theoretical ones.
• You stay current: RAG patterns, agentic frameworks, what’s actually working vs. what’s hype and you apply that judgment to real product decisions.
• You treat AI features as hypotheses. Build, deploy, measure, adjust. You own that whole loop, not just the build part.
• You can break down non-deterministic outputs into something the rest of the team can reason about and act on.
• You’re comfortable working with Ruby on Rails & React and understand how to integrate AI models into scalable, cloud-native environments.
• You help teammates who are transitioning from deterministic to probabilistic thinking, not by lecturing, but by working through it together.
• 4+ years in software engineering, with some track record (or serious curiosity) around shipping AI features.
• You can explain a complex technical decision in English to someone who doesn’t write code clearly, without condescension.

What You’ll Be Doing?

• You’ll spend more time designing systems than writing syntax. That means breaking down complex tasks, defining architecture, and writing high-level prompts that instruct multi-agent systems to generate the underlying code.
• You review and validate what the agents produce. Security, scalability, structure, that responsibility sits with you, not the model.
• You’ll work on orchestrating multiple AI agents running in parallel, keeping them in sync and making sure the output is coherent across the whole feature.
• There’s no established playbook for a lot of this. You’ll define your own workflows, experiment, and share what works because the team moves fast enough that information silos are a real risk.

How We Work (Barcelona or Madrid Office)

At Factorial, we believe the best products are built when people come together, in person to collaborate, challenge ideas, and move fast. That’s why our Engineering Teams follows an office-first, flexible schedule.

We work on-site several days a week, using that time to connect, align, and innovate as a team. However, we also understand the importance of focus and flexibility, so we support remote work when it makes sense - whether for deep work, personal needs, or just a change of scenery.

This balance helps us stay agile, creative, and closely connected, while giving everyone the space to do their best work.

At Factorial we don’t evaluate you by years of experience but by your knowledge and skills.

We use our Career Path with a rubric framework where we define what is expected for each experience level and skill. This framework allows you to know your current level and what you need to keep growing. We love transparency, so our Career Path includes the salaries for each level, which we share during the first interview to ensure alignment.

Our Hiring Process

Intro Call → Chat with our Talent Partner about your journey and goals.

Hiring Manager Interview → Deep dive into your product mindset, teamwork, and problem-solving.

Live Challenge → A collaborative technical exercise based on real-life problems.

Final Coffee Chat → A relaxed conversation with our CTO & VP of Engineering to explore our vision, culture, and your growth.

The whole process is remote, using videoconferencing tools!

About Factorial

At Factorial, we’re building the leading AI Business Management Software for companies of all sizes. Our platform centralizes key workflows across HR, Finance, Talent, Operations, and IT, freeing teams from manual processes so they can focus on what really matters: leading, growing, and taking care of their people. With over 1,500 employees across Europe, Asia, Africa, and America. We are one of Europe’s fastest-growing SaaS companies, proudly headquartered in Barcelona. If you’re excited to shape the future of business management technology, we’d love to meet you.

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.

Perks of being part of our team

• High growth, multicultural and friendly environment
• 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
• Nora discounts
• Free caffeine and theine
• Pet Friendly
• Much more that we’ll spill during the interview process!