We’re looking for a versatile machine learning engineer / data scientist to help us grow our real-time bidding (RTB) ad management services across Outbrain and Zemanta infrastructure. We are working with huge scale: currently managing tens of thousands of ad campaigns and tens of millions of ad impressions per day. Our real time bidding infrastructure handles more than 1.000,000 bid requests every second, and it needs to decide which ad to show for every one of them in real time using machine learning. This generates terabytes of data daily that needs to be processed quickly and efficiently.

As a machine learning engineer / data scientist you will be taking our data science opportunities all the way from ideas to solutions – from identifying and formulating the problem with our product managers and colleagues, through exploring terabytes of data, building predictive models and running thousands of offline experiments. Then choosing best models and deploying them to production in A/B tests, analysing the results and looking after your models in the wild by monitoring and tracking their behaviour.

We understand some people have better engineering skills while others are more versed in data science and machine learning. We like to do both. So if you’re an excellent and quick software engineer with a hacker mentality, who doesn’t have tons of machine learning experience yet but has a great passion for it, we are very excited to give you an opportunity to grow your data science and ML knowledge with our experienced data scientists. And likewise, if you’re an experienced data scientist who solved many interesting problems using advanced machine learning methods but do not consider yourself a programming wizard (yet), we will give you an opportunity to grow your engineering skills by working on highly-scalable production codebase with our experienced engineers.

What it’s like to be an engineer at Zemanta?

We solve hard problems: like processing >1 million bid requests per second efficiently, keeping tens of thousands of advertising campaigns in sync across multiple 3rd party systems and managing a database with billions of entries and >100k qps. Each of those bid requests relies heavily on our machine learning algorithms.

We use the right tools for the job: Our stack includes: Go, Python, BigQuery, AWS, Kafka, Aerospike, PostgreSQL, Hadoop, Docker, Prometheus, Grafana. We use Github for managing code, Jira for keeping track of projects and Slack to tie it all together. Our machine learning algorithms are in-house developed in either pure Go or TensorFlow. BigQuery allows us to whizz through TBs of data for analysis using SQL.

We build things that matter to our users: Engineers work closely with our product team to understand how customers use our product. This helps us make better decisions when building new features.

We care about quality: We don’t just want things done, we want them done right. We cannot imagine life without continuous integration, one-click automated deployments, code reviews, technical specs, architecture design reviews and unit tests. We find beauty in simple and elegant solutions and flexible architectures.

We push people out of their comfort zone: If you want to grow, you’ll get all the responsibility you can handle. Our engineers take full ownership over projects, which includes everything from defining a solution with product managers, planning, architectural design, implementation, testing, deployment and maintenance. If this sounds overwhelming, don’t worry – you’ll get plenty of support from more experienced members of the team.

We are a small team with global impact: Since joining Outbrain we’ve become a part of a global engineering team, which opens up lots of new opportunities for us. We collaborate with engineers and product managers based in Tel Aviv on a daily basis. That said, we’re still Zemanta – a closely-knit team with distinct identity.

We constantly try to improve: We share knowledge through internal weekly tech talks, postmortems, code reviews, blog posts and meetup talks.


  • 2+ years of software engineering experience.
  • Machine Learning and Data Science knowledge and experience are a big plus, desire to build on it is a must.
  • Good knowledge of modern backend development, databases, basic data structures and most common design patterns.
  • Ability to write clean, maintainable, well-tested production code.
  • A strong desire to learn and grow as a member of a talented engineering and data science team.
  • You lean towards simple and effective solutions and are allergic to over-engineering.
  • You set very high standards for yourself and you are constantly improving your skills.
  • We expect you to like working with people – you’ll be doing that a lot.
  • You are a reliable, trustworthy person that keeps their promises and takes responsibility for their actions.
  • Having experience with our stack is a plus, but not mandatory – we value talent, strong fundamentals and dedication to excellence more than the tools you’ve used.


We care deeply and invest heavily into our team, setting everybody up for growth and success. In addition to being a part of a great team, working in a fast-paced startup environment, learning from other smart people and skyrocketing your skills, we offer:

  • International environment: be a part of a global Outbrain engineering team
  • Full-time employment with an attractive salary package
  • Stock options plan
  • Traveling to world’s leading software engineering conferences every year and learning from the best
  • A laptop and other equipment of your choice
  • Opportunity to give back to community – by open-sourcing code, giving talks and sharing knowledge through our tech blog
  • Flexible working hours and an ability to work from home occasionally
  • Free access to the gym and pool across the street to keep you in shape

Not from Ljubljana? No problem – if you’re the right person for the job, we will help you with your relocation.

About Zemanta an Outbrain Company

At Zemanta, we're building the most advanced native advertising platform in the world. Marketing agencies love our dashboard - they use it to run native advertising campaigns that can spend hundreds of thousands of dollars per month. Offering them the tools they need to be successful is our main priority, so we are expanding our team to take our platform to the next level.

Zemanta recently joined Outbrain, the largest native advertising company in the world, on their mission of enabling everyone to discover great content.