We’re looking for a Machine Learning Engineer to join our tech team and help build the future of neuro-contextual advertising at global scale.

Who We Are

At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist.

As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next.

Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader.

If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here.

Your Challenge

As a Machine Learning Engineer, you will operate across the full stack of applied machine learning, contributing wherever impact is highest. You will:

• Design, train, evaluate, and improve ML models.

• Transform research prototypes into robust, production-grade systems.

• Build and maintain scalable ML services and APIs in Python and/or Go.

• Deploy models in high-throughput, low-latency environments (120k+ req/sec, ~10ms response times).

• Collaborate on data pipelines and feature engineering workflows, ensuring reproducibility and data quality.

• Contribute to CI/CD pipelines for ML systems, model versioning, monitoring, and automated retraining.

• Optimize inference performance, memory usage, and cloud cost efficiency.

• Work closely with Data Scientists, Backend Engineers, and Platform teams to deliver business-driven outcomes.

• Take ownership from idea to production — including experimentation, validation, deployment, and monitoring.

• This is a role for engineers who are comfortable switching contexts: one day improving a model, the next optimizing a Kubernetes deployment, and the next designing a new API endpoint.
  
  

Our Core Values

Outcome over Output
We measure success by impact and value, not by volume of features or lines of code.

Failure Is Allowed, Learning Is a Must
Experimentation is key to innovation. We test early, iterate often, and learn fast.

We Are All Scouts
We take ownership and leave things better than we found them.

We Are Data-Driven
Data informs our decisions and helps us continuously improve our systems and results.

Tech Stack

We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily.

Our stack includes:

• Python & Go microservices

• Kafka, Kinesis, Redis, GCS

• Kubernetes on GCP & AWS

• Druid, MongoDB, scalable data lake architecture

• Typescript (Node.js) and Scala across other parts of the company
  
  

What You’ll Need to Succeed

• 3–6 years of experience building and deploying ML systems in production.

• Strong Python skills and solid software engineering fundamentals (APIs, async programming, testing, clean architecture).

• Experience working on both model development and production deployment.

• Understanding of distributed systems, microservices, and cloud-native environments.

• Familiarity with MLOps practices: model versioning, monitoring, CI/CD, reproducibility.

• Experience with NLP, embeddings, and/or ranking models is a plus.

• Comfortable debugging across layers: model behaviour, data issues, API performance, infrastructure bottlenecks.

• Strong ownership mindset and ability to operate autonomously in fast-moving environments.
  
  

Why Join Seedtag?

• A key moment of growth with real ownership and global impact.

• Flexible work model with 100% remote or hybrid options.
  (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.)

• Continuous learning through a learning platform and optional language classes.

• A supportive, trust-based culture that values well-being.

• Team activities, offsites, and opportunities to connect beyond work.
  
  

Additional Perks

• Home office setup budget up to €1,000

• Paid trips to our HQ in Madrid

• MacBook Pro M3
  
  

Ready to Join the Seedtag Adventure?

At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience.

Send us your CV and let’s build the future of neuro-contextual advertising together.