Your browser cookies must be enabled in order to apply for this job. Please contact if you need further instruction on how to do that.

Staff Java Engineer

Data Science/Analytics | Prague, Prague, Czech Republic | Full Time

Job Description

Position Title: Staff Java Engineer

Position Description:

Tapjoy's Optimization platform sits at the centre of Tapjoy's mobile advertising business, handling large scale (> 1 billion requests a day), and determining which ads to show to which users. We’re looking for a skilled engineer to join our Data Science group. If you’re committed to code quality, enjoy working on complex systems at scale, and like contributing to architectural decisions this could be the job for you.

As a Java Engineer you'll work with our Data Science development team in London, developing new features while also working to improve the existing system. We have an exciting roadmap of new features, our team is expanding, and we are growing as a product on a week by week basis.

You'll enjoy working collaboratively, have an eye for detail, strong software design skills, and be interested in working with high volume, low-latency systems.


  • Work with the Data Science team to design, build, and integrate new machine learning models
  • Write robust, scalable code, supported by tests
  • Refactor existing code where necessary
  • Integrate and use a variety of supporting systems, including Couchbase, MemSQL, S3, AWS SageMaker, Apache Kafka, NewRelic, SignalFX and others


  • You possess strong computer science fundamentals, including knowledge of data structures, algorithms, and object-oriented design
  • You have strong SQL understanding and some data analysis experience
  • You are proficient with Java, and integrating APIs
  • Enjoy working collaboratively
  • You feel confident to plan out your own tasks and communicate progress, but willing to ask for help when needed


  • B.S. or M.S. in Computer Science or related field
  • 8+ years of Java Software Engineering experience
  • Strong knowledge of data structures, SQL, software design patterns and algorithms
  • A sound understanding of dependency injection, and experience using Spring


  • Knowledge of machine learning and data mining concepts
  • Experience with performance tuning/profiling, particularly with JVMs running on Linux
  • Experience in the ad tech industry is a big plus

Tapjoy is a leading mobile advertising and app monetization company. Our platform empowers advertisers to connect with over 1 billion monthly active users through value exchange advertising that drives awareness, engagement, and the metrics that matter most to their overall growth. Meanwhile, companies such as Scopely, Glu, Ludia, and many of the Top 200 grossing app publishers trust our platform to monetize their content, grow their audiences, and reward their users. Founded in 2007 and headquartered in San Francisco, Tapjoy is a global organization with offices in Santa Barbara, Boston, London, Beijing, Tokyo, and Seoul.

Tapjoy is an equal opportunity employer. We believe that diversity and inclusion lead to stronger, more innovative teams and better business results; we want to draw from the broadest talent pool possible and encourage qualified applicants. Tapjoy does not discriminate on the basis of sex, race, ethnicity, color, age, sexual orientation, gender (including identity and expression), disability (mental or physical), religion, national origin, citizenship, marital status, military or veteran status, or any other protected classification protected by applicable law; we will provide reasonable accommodations for qualified individuals with disabilities, and pursuant to applicable fair chance ordinances, we will consider for employment qualified applicants with arrest and conviction records.

For more information, please visit