We’re looking for a Backend Software Engineer - AdExchange Demand 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

You will be architecting, refining and developing the backend services that power our AdExchange. In an industry where milliseconds determine success, you will focus on:

• Optimizing the high-throughput real-time bidding systems where you'll balance ultra-low latency requirements with cost-efficiency and reliability, ensuring our infrastructure scales sustainably.

• Integrating new demand partners, owning the full lifecycle from capacity planning and endpoint configuration to traffic shaping and performance validation.

• Designing pricing and auction mechanics including bid flooring systems and dynamic margin calculations, serving machine learning models in real-time to optimize revenue.

• Building event pipelines and reporting integrations that enable data teams to analyze performance, debug issues, and feed AI models.

• Working on end-to-end projects from concept to production, making technical decisions, managing priorities, and communicating effectively with stakeholders across the company.

• Collaborating closely with cross-functional teams with a data-driven analytical mindset, validating hypotheses with real data and aligning engineering work with business goals.
  
  

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 use Go, Typescript, Python, Mongo, Redis, Google Cloud, Kafka...

• Do you know them as well? ( https://stackshare.io/seedtag/backend-chapter )

• We craft high-throughput ⚙ micro-services, APIs, data pipelines, async message queues…

• We breathe DevOps, love Kanbans, Pair Programming, Peer Reviews, Continuous Discovery, Delivery and Integration.

• We are on Slack, Notion, JIRA, and GitHub
  
  

What You’ll Need to Succeed

• Strong backend expertise: 5+ years of experience building scalable, high-performance backend systems.

• Code quality mindset: You write clean, maintainable code and apply solid programming practices and patterns.

• Distributed systems experience: Comfortable working with high-throughput systems, large datasets, and scalable architectures.

• AI-augmented productivity: You use AI tools to accelerate development, debugging, and learning.

• Big-picture thinking: You understand technical and business needs and align your work with company goals.

• Problem-solving mindset: You enjoy tackling complex challenges and finding effective solutions.

• Continuous learner: You stay up to date with backend technologies and continuously improve your skills.

• Strong collaboration skills: You communicate clearly and work effectively with technical and non-technical stakeholders.
  
  

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.