Senior Data Scientist

About the role

You will serve as the expert responsible for driving critical business initiatives through advanced analytical methods and machine learning innovation. In this capacity, you will own the development and optimization of core systems that define our commercial success, including User Acquisition models, LTV predictions, and Ad Monetization strategies. You will leverage deep analytical expertise to shape our product roadmap by extracting actionable insights from complex Product Analytics datasets. Furthermore, you will lead the design and execution of A/B testing initiatives, applying scientific rigor to validate hypotheses and guide strategic decisions. If you are motivated by high-impact challenges and wish to influence the direction of a rapidly evolving product, this role is tailored for your strengths. Your work will directly influence the scalability and profitability of our JustPlay app in a fast-moving environment.

Key facts

What you'll do

Design and construct robust machine learning pipelines to power User Acquisition models, ensuring precise targeting and efficient growth.

Conduct sophisticated Product Analytics to dissect user behavior, identifying friction points and opportunities for experience enhancement.

Architect and manage large-scale A/B testing frameworks, applying rigorous statistical methodologies to evaluate product and marketing changes.

Develop and refine LTV prediction models to forecast user value and optimize long-term retention and monetization strategies.

Deploy advanced statistical analysis techniques to transform raw data into clear, actionable narratives for cross-functional stakeholders.

Collaborate with engineering teams to integrate machine learning models into production environments, ensuring scalability and reliability.

Utilize deep learning approaches for complex tasks such as image recognition and natural language processing to support ad optimization and user engagement.

Partner with marketing leadership to translate analytical findings into testable growth hypotheses and campaign optimizations.

Lead data science projects from initial conception through deployment, coordinating timelines, deliverables, and stakeholder alignment.

Establish best practices for data visualization and reporting, enabling non-technical teams to monitor key performance indicators independently.

Champion a culture of data-driven decision-making by ensuring that insights are reproducible, transparent, and grounded in solid experimental design.

Act as a technical leader in the cross-functional team, mentoring junior analysts and data scientists on methodology and tools.

Requirements

You must possess a minimum of 6 years of professional experience in data science, with a strong focus on machine learning, statistical analysis, and deep learning applications. This experience should ideally be complemented by a background in the mobile gaming industry, providing context for sector-specific challenges. You have proven expertise in user acquisition modeling, product analytics, and A/B testing methodologies, along with fluency in the associated tools and frameworks. You demonstrate proficiency in Python, leveraging libraries such as Pandas, NumPy, Scikit-learn, TensorFlow, and PyTorch to solve complex problems. You have hands-on familiarity with SQL for database querying, data extraction, and manipulation to support analytical workflows. You maintain a strong knowledge of statistical methods and understand how to apply them effectively to derive business insights and measure impact. You have practical experience with cloud platforms such as AWS or GCP, utilizing their services to build and deploy data-intensive applications. You exhibit strong project management skills, with a documented track record of successfully leading data science projects from inception to completion. You communicate excellently, capable of translating highly technical findings into clear insights for both technical and non-technical audiences. You are a strong problem-solver who thrives in a collaborative cross-functional team environment and manages competing priorities effectively. You communicate fluently in English, both written and spoken, to ensure seamless collaboration across global teams.

Nice to have

You bring experience with mobile gaming analytics, allowing you to quickly understand industry-specific metrics and user lifecycles. You have hands-on experience with Looker for data visualization and reporting, creating dashboards that drive strategic decision-making. You possess familiarity with ad tech tools and platforms, such as Google Ads, Facebook Audience Network, and Firebase, to optimize media performance. You have knowledge of reinforcement learning and its applications in gaming or ad optimization, exploring advanced strategies for automated decision-making.

Practical notes

Work-Life Balance and Flexibility: The role operates under a hybrid model based in Berlin, offering flexibility for digital nomads, occasional office visitors, or regular office-goers.

Mental Health Support: Free personal coaching through our partner nilo.health http://nilo.health is available to support your well-being at work and at home.

Training & Development: You receive a competitive personal development budget of up to 2000€/year for training, conferences, workshops, and continuous learning.

Germany-Based Benefits: You are entitled to 25 vacation days, a free Wellhub https://wellhub.com/de-de/ gold subscription, a free monthly Deutschland-Ticket, and a monthly €50 tax-free internet contribution.

State-of-the-Art Equipment: Regardless of whether you use a MacBook or Windows, we will provide the technical gear you need to succeed in your role.

A Relocation Package: This includes visa support for candidates who require it to join us in Germany.

Berlin Office Perks: You will enjoy an ergonomic setup, free daily lunch, and a dog-friendly environment in our Berlin office.

Engaging and Diverse Work Environment: You will join a diverse team with over 30 nationalities working from more than 25 different locations.

Please note that benefits may vary depending on location and contract type. Do not hesitate to ask us about more details regarding our benefits offer.

About us

Come join the team building the engine behind rewarded mobile gaming - making playtime truly rewarding. At JustPlay, we're on a mission to power a fairer, more sustainable rewarded gaming ecosystem where users earn real value for their time through a self-sustaining model.

Since launching in 2020,