(Senior) Data Scientist | GenAI

Barcelona, Spain
OLX – Data Science and Analytics /
Full-time /

At OLX, we work together to build a more sustainable world through trade.
We make it safe, smart, and convenient to buy and sell cars, find housing, get jobs, buy and sell household goods, and more. Our colleagues around the world help to serve millions of people around the world every month, through its well-loved consumer brands including OLX, Otodom, Property24.
Join OLX and see how far you can go.


We invite you to join us on a critical and exciting mission! To expand and scale our recent investments in the Generative AI area to not only embark on exciting projects with our internal customers but also to lead OLX into the future with LLMs and Generative AI. This is a unique opportunity to be part of a strategic movement inside the company, building a team from scratch! A team that will break through walls and build cross-functional connections with everyone around. A team where a common mission and goals matter more than reporting lines. We build on each other, asking for help and support when needed, and we proactively support others. 

As a Data Scientist in the team, you will work with an amazing squad composed of different profiles such as Data Scientists, MLEs, Engineers, Product Managers, and Analytics. Our focus areas revolve around Generative AI and Large Language Models, where we operate within two key Streams: Platforms and Transversal Services (Demand and Supply teams). Those two will be part of our Data organization. The first of the Streams will focus more on enabling capabilities or back-office optimization, creating infrastructure for applying Generative AI at scale (and with controlled cost), with the initial area of application being Trust and Safety (yet another stakeholder for us). Besides, this team shall be supporting stakeholders in the development of GenAI Product roadmaps across the EU. The second Stream is dedicated to crafting customer-centric solutions focused on enhancing the discovery experience and seller features, such as:

- Validate and build reusable GenAI services and functionalities, including new user-facing innovations using video, voice, and agents, among others, for the later benefit of the CUs;
- Prepare for next-level classifieds with new GenAI-enabled capabilities, in the form of reusable services across CUs
- validate GenAI-enabled solutions which can provide a step change to the user experience, but are riskier (and therefore might not have space in short-term Product roadmaps). These opportunities are likely to “fall between the cracks. So, your turn!

In your role, you'll delve into cutting-edge machine learning techniques, specializing in LLMs and GenAI, while also providing technical guidance to junior team members. Applying AI methods to core OLX product platforms deployed in the cloud that are affecting the user experience for millions of visitors per month, rolling your solutions to production, analyzing model results offline and online, and measuring site impact. All using Python and the AWS cloud. You will be exposed to key stakeholders, have direct contact with internal customers. You will have the carte blanche to experiment and test things. And most importantly, you will also witness how your work impacts the day-to-day business of our customers.

What you will do in Data Science at OLX:

    • Work in the Data Science team, focusing on LLMs and GenAI, from a platform and marketplace perspective.
    • You will build models, tinker around them to make them work, test them, and eventually deploy them to production. You will see your stuff in action and you will be able to measure the true impact of your models (less expected, yet a requirement)
    • You will maintain strong relationships with stakeholders. This means asking a lot of questions to business people and translating their requirements into achievable projects. It also means collaborating with other teams, like infrastructure and data engineering to get things done in an elegant and timely manner.
    • Partner with Engineering and Product to deliver solutions (customer-facing and platforms) to our customers (internal and end customers) 
    • Work with Product Analytics to track the KPIs of different ML use cases and measure the impact on our customers. 
    • Partner with the Experimentation team to integrate the KPIs and their proxies into the Experimentation (A/B testing) platform.
    • You will work in multi-functional teams, in a diverse, multinational environment, filled with people from Portugal, Bulgaria, Romania, Poland, Ukraine, Kazakhstan, and Uzbekistan.
    • Most importantly you will have fun working with us :)

Who we’re looking for:

    • You must be located in Spain.
    • Very strong analytical skills. Like really strong! So strong that truth and light are your two middle names.
    • Solid background in statistics and modeling.
    • Good knowledge of Python, which means having experience with at least one of the following: Scikit-Learn, TensorFlow, PyTorch, or Pandas.
    • Hands-on experience with Machine Learning (supervised, unsupervised, etc.). 
    • Very good knowledge of NLP and Deep Learning (Embeddings, Language Models, Transformers, etc.).
    • Good knowledge of Generative AI and Large Language Models (LLMs).
    • Good understanding of engineering best practices, that is: testing, CI/CD, monitoring, alerting, and containers.
    • Hands-on experience with SQL.  
    • Experience with MLOps.
    • Proficient in English with excellent written and oral communication skills!
    • Strong presentation skills.
    • Able to work in diverse, multi-functional teams with people from different backgrounds.

Nice to have:

    • Exposure to other programming languages such as Kotlin, Java, Scala, etc
    • Experience bringing models into production and serving models at scale
    • Experience using AWS for deploying machine learning solutions
    • Experience with building data pipelines using tools like Spark and Airflow
    • Understanding of A/B testing and experimentation
    • Exposure to MLOps tools

Our benefits

    • Permanent contract
    • Salary + annual bonus up to 15% of your annual gross salary
    • Work with and impact all OLX websites
    • Train and conference budget and free access to Udemy courses
    • Health insurance and life insurance
    • MacBook Pro or Windows Dell along with necessary accessories to make your work comfortable
    • 100% remote work (and the possibility to work from our office in Barcelona)
Why join OLX? 
At OLX, we invest in ourselves and each other to reach our full potential. We avoid bureaucracy and empower our teams to innovate; with opportunities, training, and leadership behaviors a key focus for all. Our commitment to inclusion ensures we listen to a diverse range of voices when making decisions. And, we combine the spirit and agility of a startup with our global scale and the backing of Prosus, one of the largest consumer internet groups in the world.

Diversity, Equity and Inclusion at OLX
At OLX, we are committed to creating a diverse, inclusive, and authentic workplace. We strongly encourage people of all races, ethnicities, disabilities, ages, gender identities or expressions, sexual orientations, religions, backgrounds, and experiences to apply.
If you are excited about this role, and your past experiences do not align perfectly with every criteria asked for in the job description, we would still like you to apply. You may be just the right candidate for this or other opportunities across the business, and we'd like to hear from you.

OLX (OLX consists of OLX Global B.V. and its affiliated companies) will handle your personal data with care and will process your personal data to assess your fit for the position you are applying for. You can give your consent (optional) to allow us to store your data for up to 12 months after the application process. So that in case you are not fit for the role at stake we can consider you for other suitable roles.   
Please refer to our Privacy Statement to find out more about how your application data will be processed.