Machine Learning Engineer

WELCOME TO OLX

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.

Data Science org

The Data Science team at OLX Group is responsible for building algorithmic solutions to facilitate transactions between buyers and sellers. We are developing personalization technologies and optimization strategies that have a direct impact on OLX’s users as well as the company’s bottom line.

You will be encouraged to research state-of-the-art machine learning, in the areas of search relevance, ranking, recommender systems, and more. Applying these 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.

Some of the challenges that we are focusing on are maximizing the relevance of the search results by applying ML-based rankers, combining different sources of ads in search and recommendations to optimize the satisfaction of both buyers and sellers, estimating the impact that the interactions generated by the buyers have on the revenue, and detecting trending products even before they become popular.

The Search Data Science team

The Search Data Science Search at OLX Group is responsible for building and scaling search methods that are incorporated into our search engine across OLX Europe. Our main goal is to help our stakeholders increase efficiency and performance by delivering Search techniques across our platform to serve our customers when looking for items in our vast catalog. In a nutshell, you will be exposed to projects such as: Semantic Search powered by vector search (to deliver the most relevant results by interpreting the user’s intent and understanding their needs), Category identification (delivering items corresponding to the identified category from the user's query, such as the fashion category), Attribute extraction (deriving searchable fields from the user's query, like the color of a t-shirt).

Our team collaborates with product teams from OLX, as well as the Motors and Real Estate verticals like Otomoto and Otodom, across the entire EU region. This means that our solutions need to scale to millions of data points and may be reused in markets with similar characteristics. We think of experimentation as a tool to learn what our users want. We always start simple and fail fast. This way we can create solutions that can be adapted to every market.

Right now, we're hiring a mid-level Machine Learning Engineer. On a typical day, you will be implementing machine learning pipelines and taking our ML solutions to a production-ready state. You will collaborate with data scientists in all the stages of an ML project, starting from data extraction to preprocessing, training, evaluating, and serving the predictions to our end users. You will work with engineers to monitor our models, make our ML services fault-tolerant, optimize performance and cloud costs. In any case, you will find a group of friendly people who want to collaborate with you to improve the user experience and ultimately have fun together!

What you will do as a ML Engineer at OLX:

• Work in the Search team, focusing on developing and optimizing search techniques.
• You will help build models, refine them for optimal performance, test them, and eventually deploy them to production.
• You will see your work in action and measure the true impact of your models on our platform.
• You will maintain strong relationships with stakeholders. This involves asking numerous 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 efficient and elegant manner.
• Partner with Engineering and Product to deliver solutions, both customer-facing and platform-based, to our internal and external customers.
• Work with Product Analytics to track the KPIs of different machine learning use cases and measure their impact on our customers. Collaborate with the Experimentation team to integrate 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 are we looking for:

• At least 2 to 3 years of professional experience as a MLE
• Experience participating in projects related to search relevance and ranking
• Good knowledge of the best engineering practices
• Experience with building data pipelines using tools like Spark and Airflow
• Experience with serving machine learning models at scale
• Strong engineering background: excellent knowledge of Python, exposure to other programming languages (Kotlin, Java, etc)
• Experience in using machine learning frameworks in production settings: Scikit-Learn, TensorFlow (or similar)
• Experience using cloud-based architectures for deploying machine learning solutions
• Proficient in English with excellent written and oral communication skills

Nice to have:

• At least some knowledge of Generative AI and LLMs (e.g., foundations like Transformed-based architectures, embeddings, etc.)
• Exposure to other programming languages in the past 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

What we offer:

• Permanent contract
• Salary + annual bonus up to 15% of your annual gross salary
• Work with and impact all OLX services in Europe
• Train and conference budget and free access to Udemy courses
• Health insurance and life insurance
• MacBook Pro 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.

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