Mid-Level

Agentic Platform Engineer

Paris, France, Milano, Italy, Madrid, Spain, London, United Kingdom, Hamburg, Germany, Düsseldorf, Watermael-Boitsfort, Belgium, Barcelona, Ouderkerk aan den Amstel, Netherlands · Hybrid

We’re looking for an Agentic Platform 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 500+ 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 our Agentic Platform Engineer, you will help build and scale Liz Agent, Seedtag's AI agent platform, ensuring reliability, security, and seamless integration across teams.

Your main responsibilities will include:

Agent Platform Development: Build and maintain the core Liz Agent runtime, including agent execution, context management, and event streaming.
Tools & Integrations: Develop MCP tool servers, APIs, and integrations that enable secure access to internal data and services.
Agentic AI Capabilities: Improve agent functionality through memory, multi-model routing, durable execution, and LLM frameworks.
Reliability & Observability: Monitor platform performance, troubleshoot production issues, and improve tracing and evaluation capabilities.
Platform Engineering: Contribute to APIs, service templates, CI/CD pipelines, and cloud-native deployments that enable teams to build agents independently.
Security & Quality: Implement security best practices, automated evaluations, and regression testing to ensure reliable agent behaviour.
End-to-End Ownership: Take responsibility for features from development to deployment and monitoring, collaborating with Data, ML, Platform, and Product teams.

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

You'll work with the technologies powering Liz Agent, our AI agent platform, built on 30+ services running on GKE.

Our stack includes:

Languages: Python, Go.
Cloud & Infrastructure: GCP, GKE, Kubernetes, Vertex AI, BigQuery.
Agentic AI: MCP, PydanticAI, Claude Agent SDK, LangGraph, OpenAI Agent SDK.
Data & Messaging: Pub/Sub, Redis, Firestore.
LLMOps & Observability: Langfuse, Prometheus, Logfire, LiteLLM.
DevOps & CI/CD: ArgoCD, Kustomize, GitHub Actions.
Additional Technologies: TypeScript, Next.js, embeddings, vector search.

What You’ll Need to Succeed

3+ years of experience building and maintaining backend systems in production.
Strong Python expertise, including APIs, asynchronous programming, testing, and clean architecture.
Hands-on experience developing LLM applications or AI agents, including tool calling, structured outputs, and evaluations.
Solid understanding of event-driven architectures, microservices, Kubernetes, and cloud infrastructure.
Experience with LLMOps, observability, CI/CD, and production troubleshooting.
Knowledge of AI security practices, including authentication, access controls, and prompt-injection protection.
Ability to own features end to end, work autonomously, and collaborate effectively with cross-functional teams.

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.

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