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Senior Java Developer – Predictive Applications

Our Data Science team in Paris works on developing new Machine Learning algorithms for acquiring audiences and maximizing client revenue with cross-device acquisition and advanced retargeting. Given the massive volume of information we process, and the low latency required by our real-time platforms, a full-fledged engineering team is needed to integrate these Machine Learning algorithms in production. Among others, the following computing fields are crucial in this context

  • High volume log centric architectures: ML models are very hungry and we have PBs of data available in the Rakuten ecosystem
  • Low latency / high frequency programming: we aim to be able to make millions of predictions per second
  • Testing / Software craftsmanship: our platform needs to run 24/7, there is little room for mistakes
  • Online Machine Learning models integration: we have a wide range of models that need to be implemented in the most efficient way possible.

Rakuten Marketing is looking for a Senior Java Developer to join its teams in Paris to work on predictive applications.


  • Get the data science algorithms from the testbed to the production platform.
  • Design scalable and reusable software architectures for a wide variety of predictive algorithms and revenue models.
  • Develop performance metrics to monitor the health and the effect of the features you will develop.
  • Test, test, test! Write unit tests, collaborate with QA teams to design end-to-end tests and develop testing strategies to be able to push your code to production with 100% confidence.
  • Keep your documentation tidy and usable to let the other engineering teams seamlessly use your work.

Required Skills:

  • Graduated from a Scientific or Engineering School or a Master’s program in Computer Science.
  • Intimate knowledge of the Java platform and of its inner workings. (5-7 years of experience).
  • Real experience in designing, programming and scaling low latency high frequency systems.
  • Knowledge of multi-threaded and reactive programming.
  • Experience in a log-centric architecture context.
  • Unit testing, end-to-end testing, metrics design.
  • Fluent in Java 8, especially functional programming and streams.
  • Basic knowledge of statistics, probabilities and linear algebra. Nothing complex but you should know how to compute a mean, a variance and how to multiply matrices.
  • Advanced level in written English and good communication skills.

Optional Skills:

Having these skills would definitely be a plus. If you do not have them, you will definitely learn them on the job

  • Experience in web advertising technologies.
  • Experience with servlet technologies.
  • Experience in Data Engineering, especially Spark / Scala.
  • Hands-on experience with Machine Learning Algorithms Integration, including testing.


  • Health Insurance covered at 100%
  • Lunch vouchers reimbursed at 50%
  • Transportation fee reimbursed at 50%
  • Frequent social events
  • Annual company trip: last one was a ski trip in Val Thorens
  • Paid participations to conferences and paid online training
  • Strong intercultural work environment
  • Not being a cog in the machine, you will get a complete view of predictive applications in the AdTech world. You will be able to see the benefits of your work on our company in real time.

About Rakuten Marketing: Rakuten Marketing is the global leader in integrated marketing solutions. With 16 offices around the world, our integrated marketing solutions span affiliate, display and search. Headquartered in San Mateo, CA, we have offices throughout the United States and in Australia, Brazil, Japan, Singapore, the United Kingdom, Germany and France. Rakuten Marketing empowers marketers to transcend the conventional and achieve the full potential of digital marketing. We deliver data-driven personalized ad experiences that engage consumers – across screens, platforms and traditional publishers – and influence them to purchase. Our commitment to transparency provides consumer journey insights that allow us to continually optimize for performance.

Rakuten Global: Rakuten Group is one of the world’s leading internet service companies, providing a variety of consumer and business-focused services including e-commerce, e-reading, travel, banking, securities, credit card, e-money, portal and media, online marketing and professional sports. Rakuten is expanding globally and currently has operations throughout Asia, Western Europe and the Americas. Founded in 1997, Rakuten is headquartered in Tokyo, with over 10,000 employees and partner staff worldwide. To learn more, we invite you to visit our global home.

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