Senior Data Scientist - Machine Learning

Catawiki; Amsterdam; On-site; EUR 110,000 - 160,000; Full time

Benefits offered by this job

Stock options

Hybrid work

Office in Amsterdam

Pension plan

Job summary

Catawiki in Amsterdam is seeking a Senior Machine Learning Data Scientist to build scalable data products and real‑time predictions. You’ll work with product and engineering teams to deploy models and extract insights from vast event data.

You have 5+ years of data science experience, strong Python and SQL skills, and a track record delivering production ML systems using Kubernetes and cloud infrastructure. Hybrid work in Amsterdam.

Qualifications

• 5+ years of data science experience.
• Fluent in Python and SQL.
• Experience building production ML models.
• Ability to deploy models at scale using Kubernetes.

Responsibilities

• Build production‑ready ML models for the product offering.
• Explore data to identify ML opportunities and business problems.
• Deploy scalable models on cloud infrastructure for real‑time and batch predictions.
• Collaborate with product, engineering, UX, and analytics teams to define use cases.

Skills

Python

SQL

Machine Learning

Realtime Inference

Tools

Kubernetes

Docker

PyTorch

TensorFlow

Job description

At Catawiki, every day brings the extraordinary.

We’re a one‑of‑a‑kind marketplace for buying and selling special objects. Each week, more than 100,000 unique items are auctioned, all carefully curated by our passionate in‑house experts.

Senior Data Scientist - Machine Learning

Our Data Story

With ten‑thousands of active items on auction every day, hundred‑thousands of bids, millions of users, and billions of events, the Catawiki platform generates vast amounts of data. We collect this data centrally, using it to generate business insights, as well as powering machine learning models that enhance our user experience, optimize our workflows, and keep our platform safe. We believe in creating flexible models that can be applied to a variety of use cases, and in experimentation and iteration to hit the ground running and continually improve the tools we build.

The Data Team covers the full data spectrum of Machine Learning, Analysis and Data Engineering, and has a clear mission within Catawiki.

Why

We believe that by using data in a smart way, we can build the best Catawiki possible. We want to have impact and see opportunities everywhere.

How

We are builders, thinkers and talkers. We collaborate closely with every department to create value for our customers. We think big and hold ourselves to high standards, because our work really matters for the future of the company.

What

As a result we create business value by delivering scalable, robust models and actionable insights and predictions. We help the company to find opportunities and understand success, and we empower everyone to use data to be successful.

So what's the job

As a Senior Machine Learning Data Scientist in the Data Team at Catawiki, you will focus on delivering scalable and impactful data products. You’ll work closely with our product and development teams while implementing your work. This includes:

• Building production‑ready models that apply machine learning and advanced data science techniques within our product offering by writing robust and scalable code.
• Finding data science opportunities by exploring our extensive mobile and web data, and applying machine learning and advanced statistics to tackle these real‑world business problems.
• Being pragmatic when needed but also able to go deep into a problem, applying your expert knowledge of machine learning techniques.
• Working with cross‑disciplinary teams involving product owners, developers, UX designers, and business analysts in identifying improvements and new use cases for ML.
• Deploying scalable models using Kubernetes on cloud infrastructure, producing real‑time, asynchronous, and batch predictions.

Who you are

• You are an all‑around data scientist with 5+ years of experience who is as comfortable diving into the internals of a model implementation as discussing new opportunities for ML with product stakeholders.
• You can use your broad skill set to solve challenging ML problems and have a high throughput.
• You are familiar with a range of different ML techniques and use that to select a good solution for projects.
• You are able to consider the operating and deployment constraints of large models and implement solutions accordingly.
• You give guidance and unblock others in your team by supporting them with advice and new techniques.
• You have a strong quantitative background in statistics, ML, sciences, or similar fields.
• You are fluent in Python and capable with SQL.
• You have deployed ML models serving real‑time responses on a large scale.
• You have demonstrable experience in building robust data products that created value for the company you worked for.

The following are a plus:

• Proven ability to extract meaning from very big datasets with little engineering support.
• Experience with one or more of the following: PyTorch/Tensorflow, LightFM, Git, Docker, Kubernetes, Google BigQuery, MySQL, Spark, Airflow, Kafka, nginx, CI/CD.
• An entrepreneurial mindset that enables you to get things done, even if that requires actions outside your own area or comfort zone.

Here’s what we can offer you

This is your chance to become part of a fast but sustainable growing tech company. You will have an exciting role in a young, fast‑growing, dynamic and international organisation. You'll be part of an enthusiastic, highly motivated team of 800+ international Catawikians; you'll have big responsibilities and can really create something. Additionally you can expect:

An attractive Stock Options package

• Working with a top notch team acting on a champions league level in a super complex dynamic environment; you will learn a lot.
• A diverse and international team with over 50 different nationalities.
• A great office located in the heart of Amsterdam with an easy‑going atmosphere.
• Our entrepreneurial environment encourages everyone to take initiative and experiment with new ideas. You’ll actively contribute to the growth of the Catawiki platform.
• Tailor‑made trainings to facilitate your personal and professional growth.

The fun part!

• Our Activity Committee plans everything from ‘CataFooty’ to International Food Festivals, Friday Drinks, Board Game Nights, Pub Quizzes and Boot Camps.

And there’s more!

• Paid holidays, holiday allowance and a fantastic pension plan paid for by Catawiki.

Why You'll Love Working with Us

• Create a visible impact by working at scale in a global organisation serving millions of customers across 80+ categories. In our flat structure, every role has a broad scope and directly impacts both our customers and the business.
• Learn and grow through our Learning & Development initiatives, including clear development plans and mentorship programmes to support your career progression.
• Celebrate life’s moments with us. You’ll receive a €100 Catavoucher when you join, a €50 Catavoucher on your birthday, and an extra day off each year to “Pursue Your Passion”. We also offer additional leave for key work anniversaries and important life events. Benefits may vary by location.

Our Offices and Way of Working

Our vibrant offices in Amsterdam and Lisbon are designed to inspire collaboration. Most Catawikians operate in a hybrid setup, combining office‑based and remote work, with a minimum of two days per week in the office, unless a role is explicitly stated as fully remote or fully office‑based.