Arrise

Data Scientist - RecSys

Portugal full-time Mid Salary not listed
full-time Mid level Technology & IT Curated
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About the role

What you will do

Design, implement, and optimize end-to-end recommendation pipelines, from data ingestion to model inference.

Build and maintain scalable ETL pipelines to support reliable and efficient data flows.

Develop, evaluate, and continuously improve ML models for recommendation systems.

Research, prototype, and implement state-of-the-art (SOTA) approaches to improve recommendation quality and drive key business metrics.

Scale and optimize data and model pipelines to handle large volumes of data and real-time or batch processing needs.

Integrate multi-modal data (e.g., behavioral, transactional, and contextual signals) from various systems into recommendation models.

Ensure robustness and stability of pipelines by implementing unit and integration tests across data, modeling, and deployment workflows.

Monitor and maintain end-to-end system performance, including data pipelines, model quality, and downstream impact.

Design and analyze A/B tests to evaluate model performance and support data-driven product decisions.

Build dashboards and observability tools to track model metrics, system health, and business KPIs.

Collaborate closely with Data Engineers, Software Engineers, and stakeholders to deliver scalable, production-ready solutions.

What you bring

Bachelor's or Master's degree in Computer Science, Engineering, or a related field

Strong Python experience with recent production use, including hands-on work with data science and machine learning libraries and frameworks (e.g., Pandas, Polars, NumPy, scikit-learn, PyTorch, TensorFlow, JAX, Hugging Face, …)

Experience building and deploying end-to-end machine learning systems on cloud AI platforms (Azure, GCP, or AWS), from ETL pipelines to deployment and monitoring, including model versioning and experiment tracking, supporting either batch or real-time workflows.

Strong understanding of deep learning–based recommender systems for next-item prediction, and analogous NLP architectures that model sequential patterns and context

Demonstrated experience building efficient data transformation pipelines for both transactional (OLTP) and analytical (OLAP) workloads, with strong knowledge of SQL and NoSQL databases (e.g., PostgreSQL, MySQL, Redshift, Snowflake, BigQuery, MongoDB, Cassandra)

Experience with unit and integration testing (e.g., Pytest), CI/CD pipelines, and Docker-based containerization

What sets you apart

Experience building large-scale recommender systems (e.g., candidate generation, ranking, retrieval, personalization).

Track record of publications in deep learning at relevant conferences or journals.

Experience with Azure Data Factory / AWS Glue / Google Cloud Dataflow.

Experience designing and analyzing A/B tests, with a solid understanding of relevant evaluation metrics.

Experience designing and implementing metadata-driven pipelines to scale automated A/B testing systems.

Experience developing multi-modal models that integrate multiple data types (e.g., text, images, audio).

Experience applying transformer-based models or large language models (LLMs) to recommendation or personalization tasks.

Experience with distributed training, including data parallelism and model parallelism.

Experience with distributed data processing and big data technologies (e.g., Spark, Hadoop, Flink, Kafka, Hive, Presto, Databricks).

About us
ARRISE is a global leader in software development and services for the iGaming industry, bringing together more than 2,500 professionals operating across more than 12 locations worldwide.
From concept through to delivery, we combine technical expertise, creativity and industry knowledge to develop products, platforms and services that shape player experiences and support some of the industry's leading brands.
We are best known for the work we deliver for Pragmatic Play, creating and supporting technology, products and specialists services enjoyed by millions of players worldwide.
Originally posted on Himalayas

Interview prep

Walk in with sharper answers.

Use this as a quick practice sheet before you speak with the employer.

Mid
Technology & IT API integration Figma MySQL Python SQL Mid level

Likely questions

  1. Tell us about work you have done that is close to the Data Scientist - RecSys role.
  2. How would you approach your first 30 days at Arrise?
  3. Which of API integration, Figma and MySQL have you used recently, and what did it help you achieve?
  4. Describe a time you solved a problem without waiting to be told exactly what to do.
  5. How do you handle busy days, changing priorities, or pressure at work?

Prepare before the call

  • A recent example that proves your experience with API integration, Figma and MySQL.
  • One short story with a problem, your action, and the result.
  • Two examples that show the strengths listed on your CV.
  • A clear reason why this role and company interest you.
  • Your availability, preferred work style, and salary expectations.

Ask them

  • What would success look like in the first 90 days?
  • What are the main problems this hire should help solve?
  • How does the team give feedback and measure good work?
  • What does a normal working week look like for this role?
Practice line

I am interested in the Data Scientist - RecSys role because I can bring practical experience in API integration, Figma and MySQL, learn the team quickly, and contribute to the outcomes Arrise needs from this hire.

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