Machine Learning Engineer

Posted 9 Days Ago
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Barcelona, Cataluña
In-Office
Mid level
Artificial Intelligence • Logistics • Software
The Role
The Machine Learning Engineer will design, build, and maintain scalable ML systems, optimize ML pipelines, implement MLOps, and collaborate with teams to deploy models into real-time products.
Summary Generated by Built In

About HappyRobot

HappyRobot is the AI-native operating system for the real economy—a system that closes the circuit between intelligence and action. By combining real-time truth, specialized AI workers, and an orchestrating intelligence, we help enterprises run complex, mission-critical operations with true autonomy.

Our AI OS compounds knowledge, optimizes at every level, and evolves over time. We’re starting with supply chain and industrial-scale operations, where resilience, speed, and continuous improvement matter most—freeing humans to focus on strategy, creativity, and other high-value tasks.


You can learn more about our vision in our Manifesto. HappyRobot has raised $62M to date, including our most recent $44M Series B in September 2025. Our investors include Y Combinator (YC), Andreessen Horowitz (a16z), and Base10—partners who believe in our mission to redefine how enterprises operate. We’re channeling this investment into building a world-class team: people with relentless drive, sharp problem-solving skills, and the passion to push limits in a fast-paced, high-intensity environment. If this resonates, you belong at HappyRobot.

About the Role

You’ll be building AI models that make human-like conversations possible. You’ll work at the intersection of speech, language, and intelligence, taking cutting-edge research and transforming it into real-time, scalable systems that power our core products. You’ll have the unique opportunity to make a huge impact as one of our first ML hires, shaping not only the technology but also the direction of our company. From designing robust models to deploying them in production, you’ll own the entire lifecycle of ML systems and help us stay ahead of the curve in AI innovation.

About the Role
  • Design, build, and maintain scalable ML systems — from data ingestion and preprocessing to training, testing, and deployment.

  • Develop and optimize end-to-end ML pipelines (data collection, labeling, training, validation, monitoring) to ensure reliability and reproducibility.

  • Implement robust MLOps practices, including model versioning, experiment tracking, CI/CD for ML, and continuous monitoring in production.

  • Collaborate with product and engineering teams to integrate and deploy models into real-time products with a focus on efficiency and scalability.

  • Ensure data quality, observability, and performance across all AI systems.

  • Stay current with the latest in AI infrastructure, tooling, and research — helping us stay ahead of the curve.

Must Have
  • Strong experience in machine learning, deep learning, and NLP.

  • Solid background in MLOps and data pipelines — e.g., model deployment, monitoring, and scaling in production environments.

  • Proficiency in Python and familiarity with Go.

  • Experience with ML lifecycle management tools (e.g., MLflow, Kubeflow, Weights & Biases).

  • Ability to design ML systems for robustness, scalability, and automation.

  • Strong coding, debugging, and data engineering skills.

  • Passion for AI infrastructure and its real-world impact.

  • Founder mindset: ownership, independence, and willingness to go deep.

Nice to Have
  • Experience in speech recognition, TTS, or audio processing.

  • Familiarity with LLMs, generative AI, or real-time inference systems.

  • Hands-on experience with data orchestration frameworks (e.g., Airflow, Prefect, Dagster).

  • Prior experience in startup environments with fast iteration cycles.

  • Knowledge of cloud infrastructure (AWS/GCP/Azure) and containerization tools (Docker, Kubernetes).

Why join us?
  • Opportunity to work at a high-growth AI startup, backed by top investors.

  • Rapidly growing and backed by top investors including a16z, Y Combinator, and Base10.

  • Ownership & Autonomy - Take full ownership of projects and ship fast.

  • Top-Tier Compensation - Competitive salary + equity in a high-growth startup.

  • Comprehensive Benefits - Healthcare, dental, vision coverage.

  • Work With the Best - Join a world-class team of engineers and builders

Our Operating Principles


Extreme Ownership

We take full responsibility for our work, outcomes, and team success. No excuses, no blame-shifting — if something needs fixing, we own it and make it better. This means stepping up, even when it’s not “your job.” If a ball is dropped, we pick it up. If a customer is unhappy, we fix it. If a process is broken, we redesign it. We don’t wait for someone else to solve it — we lead with accountability and expect the same from those around us.

Craftsmanship

Putting care and intention into every task, striving for excellence, and taking deep ownership of the quality and outcome of your work. Craftsmanship means never settling for “just fine.” We sweat the details because details compound. Whether it’s a product feature, an internal doc, or a sales call — we treat it as a reflection of our standards. We aim to deliver jaw-dropping customer experiences by being curious, meticulous, and proud of what we build — even when nobody’s watching.

We are “majos”
Be friendly & have fun with your coworkers. Always be genuine & honest, but kind. “Majo” is our way of saying: be a good human. Be approachable, helpful, and warm. We’re building something ambitious, and it’s easier (and more fun) when we enjoy the ride together. We give feedback with kindness, challenge each other with respect, and celebrate wins together without ego.

Urgency with Focus
Create the highest impact in the shortest amount of time. Move fast, but in the right direction. We operate with speed because time is our most limited resource. But speed without focus is chaos. We prioritize ruthlessly, act decisively, and stay aligned. We aim for high leverage: the biggest results from the simplest, smartest actions. We’re running a high-speed marathon — not a sprint with no strategy.

Talent Density and Meritocracy
Hire only people who can raise the average; ‘exceptional performance is the passing grade.’ Ability trumps seniority. We believe the best teams are built on talent density — every hire should raise the bar. We reward contribution, not titles or tenure. We give ownership to those who earn it, and we all hold each other to a high standard. A-players want to work with other A-players — that’s how we win.

First-Principles Thinking
Strip a problem to physics-level facts, ignore industry dogma, rebuild the solution from scratch. We don’t copy-paste solutions. We go back to basics, ask why things are the way they are, and rebuild from the ground up if needed. This mindset pushes us to innovate, challenge stale assumptions, and move faster than incumbents. It’s how we build what others think is impossible.

The personal data provided in your application and during the selection process will be processed by Happyrobot, Inc., acting as Data Controller.

By sending us your CV, you consent to the processing of your personal data for the purpose of evaluating and selecting you as a candidate for the position. Your personal data will be treated confidentially and will only be used for the recruitment process of the selected job offer.

In relation to the period of conservation of your personal data, these will be eliminated after three months of inactivity in compliance with the GDPR and legislation on the protection of personal data.

If you wish to exercise your rights of access, rectification, deletion, portability or opposition in relation to your personal data, you can do so through [email protected] subject to the GDPR.

For more information, visit https://www.happyrobot.ai/privacy-policy

By submitting your request, you confirm that you have read and understood this clause and that you agree to the processing of your personal data as described.

Top Skills

AWS
Azure
Docker
GCP
Go
Kubeflow
Kubernetes
Mlflow
Python
Weights & Biases
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The Company
HQ: San Francisco, California
63 Employees
Year Founded: 2023

What We Do

HappyRobot's AI workers conduct communication-based tasks like emails, messages, or phone calls. Our focus is in logistics and supply chain which means our AI workers are mostly handling the operations of moving freight including sales, track & trace, accounting, and support. These tasks don’t end in a conversation - we’re also extracting valuable data and leveraging that data for things like targeting prospects or understanding pricing and demand in an all-in-one control panel for your business.

HappyRobot's platform was built as a developer tool, so although we’re experts in common logistics use cases, any custom workflow can be built. If your team is spending time sending emails or making calls, we can automate that workflow by giving AI access to the right data and good instructions.

Backed by a16z and YC, we recently closed our Series A and are scaling rapidly. If you're excited about transforming an industry that represents over 10% of global GDP & impacting the speed & cost of access to goods all over the world, join us!

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