Senior Machine Learning Engineer

ActAI; España; Presencial; EUR 90.000 - 130.000; Jornada completa

Descripción de la vacante

ActAI is seeking a Senior Member of Technical Staff, Machine Learning, to own critical ML subsystems in production and ship reliable systems at scale. You will work end-to-end from data preparation to inference, turning research ideas into production-ready systems, and mentoring other ML engineers while collaborating with research, product, and engineering teams.

Join a small, high-talent team that moves fast, values structure and judgment, and aims to bring AI with practical benefits to

Formación

• Own critical ML subsystems in production.
• Translate research ideas into working systems.
• Write production-quality code with systems thinking.
• Collaborate with research, product and engineering teams.
• Mentor and review work from other ML engineers.

Responsabilidades

• Build core ML systems powering a proactive AI product.
• Own end-to-end processes: data prep, training, evaluation, inference.
• Turn research ideas into reliable production systems.
• Debug production issues using real signals and metrics.
• Ship iteratively: measure outcomes, refine, repeat.
• Collaborate across teams to deliver user impact.

Conocimientos

Ownership

Production-grade coding

System design

ML-to-production

Mentoring

Herramientas

Python

PyTorch

JAX

GPU training/inference

Descripción del empleo

There are over 5 billion users using basic applications today such email, notes, tasks, calendar and they're not AI-native. Our mission is to build proactive applications for anyone in the world, who are not used to complex prompting. We aim to bring intelligence to conversations, errands, organising and workflows, with minimal to no prompting.

Our product focuses on achieving high reliability for long-running workflows, persistent context, and real-world task completion. We believe products will greatly reduce hallucinations.

Our objective is to organise anyone's life, allowing us all to spend time on valuable and meaningful things.

About ActAI

There are over 5 billion users using basic applications today such email, notes, tasks, calendar and they're not AI-native. Our mission is to build proactive applications for anyone in the world, who are not used to complex prompting. We aim to bring intelligence to conversations, errands, organising and workflows, with minimal to no prompting.

Our product focuses on achieving high reliability for long-running workflows, persistent context, and real-world task completion. We believe products will greatly reduce hallucinations.

Our objective is to organise anyone's life, allowing us all to spend time on valuable and meaningful things.

Role

As a Senior Member of Technical Staff, Machine Learning, you are an independent owner of critical ML subsystems in production. You take ambiguous problems, design practical solutions, and ship systems that operate reliably at scale.

This is a hands-on, high-impact role focused on depth.

Focus

• Build core ML systems that power a proactive, long-horizon AI product.
• Own work end-to-end: data preparation, training, evaluation, inference, and iteration.
• Turn research ideas into working systems that run reliably in production.
• Debug model failures and system issues using real production signals.
• Iterate quickly: ship, measure outcomes, refine, and repeat.
• Collaborate closely with research, product, and engineering to deliver real user impact.
• Mentor and review work from other ML engineers through example and technical judgment.
• Work under real production constraints: latency, cost, reliability, and safety

Tech Stack

• Python
• PyTorch / JAX
• GPU-based training and inference systems

Ideal Experience

• You have built and shipped ML systems used by real users.
• You understand how modern ML models behave — and misbehave — in production.
• You write strong, production-quality code and think in systems, not scripts.
• You take ownership, work independently, and push work across the finish line.
• You learn fast, communicate clearly, and improve through iteration.
  

Outcomes

• ML models and systems in production consistently meet accuracy, latency, reliability, and efficiency targets.
• Complex production issues are monitored, debugged, and resolved with minimal disruption.
• Training, inference, and data pipelines are robust, scalable, and maintainable over time.
• Drives measurable improvements in ML systems based on real-world signals and user feedback.
• Provides mentorship and technical guidance to peers, raising the overall ML engineering standard.
• Collaborates cross-functionally to ensure ML features integrate seamlessly into products and meet business goals.
  

How We Work

The best products today in the world were built by small, world class teams. We are a high talent density and hands-on team. We make decisions collectively, move at rapid speed, striking a balance between shipping high quality work and learning. Joining our team requires the ability to bring structure, exercise judgment, and execute independently. Our goal is to put in hands of our users a truly magical product

Interview process

If there appears to be a fit, we'll reach to schedule 3, but no more than 4 interviews.

Applications are evaluated by our technical team members. Interviews will be conducted via virtual meetings and/or onsite.

We value transparency and efficiency, so expect a prompt decision. If you've demonstrated the exceptional skills and mindset we're looking for, we'll extend an offer to join us. This isn't just a job offer; it's an invitation to be part of a team that's bringing AI to have practical benefits to billions globally.