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Do you want to build awesome, engaging mobile games and scale them to millions of users?

Senior Data Engineer (f/m/d)

  • Hamburg
  • adjoe
  • Playtime Data Science
  • Full-time
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adjoe is redefining the future of mobile ads. Powered by advanced AI, first-party data and world-class engineers, we’ve perfected the offerwall experience for monetizing and scaling app publishers with solutions like Playtime – now the fastest growing rewarded advertising channel globally – driving incremental engagement, retention, and revenue. Together, this ecosystem connects app developers to over 770 million users worldwide for scalable growth. We are a profitable, high-growth company backed by a $100 million investment from Bertelsmann. Operating from offices in Hamburg, Boston, Singapore, and Tokyo, adjoe is defining the next stages of app and ad experience – right now. Join us.

Meet Your Team: Playtime Data Science

Playtime is a time- and event-based ad unit that continuously rewards users with in-app currency – for the time they spend and events completed while playing mobile games. We connect advertisers to 700+ million Playtime users and serve 2bn requests per day at low latency. We ensure that all parties involved have a positive experience. Advertisers get more users for their apps. Monetizers earn revenue for users on their platforms. Users play fun games while simultaneously getting rewarded.

Our data science team powers the engine that distributes our ads. They solve multiple tasks such as developing algorithms to provide the most relevant ads for users, predicting user interests and inclinations, and dynamically adjusting pricing based on these predictions. Because the user base is very diverse we are using deep learning models that we could show to be able to serve the best ads to users.

Within the Playtime team you will be responsible for services and models that we use to provide automated solutions both for our advertisers and publishers.

Our Tech Stack

We strongly believe in self-hosted open source technologies backed by battle-proven AWS technologies.

  • Apache Kafka as our event streaming system

  • Apache Flink (using Java) for stateful stream processing and real-time feature engineering

  • Go as our primary language for backend

  • Kubernetes and Terraform to manage our infrastructure

  • S3 and Druid for long-term data storage

  • DynamoDB and Redis to store per-user data and power low-latency real-time aggregations.

  • TensorFlow and PyTorch for training ML models, TensorFlow Serving and Triton for inference

  • Prometheus, Grafana, the ELK stack and OpenObserve for logging and monitoring

  • Airflow for orchestration

  • … and we’re always open to trying new technologies that suit each case best.

    • Scale at a glance

  • Thousands of requests for distributions every second

  • Our ML models handle those at p99 latency of 100ms

  • 100k+ ML predictions per second

  • 2TB data ingested in real-time every day

  • 100+ Airflow jobs and other data pipelines

    • What You Will Do

  • Scale the Feature Store: Leverage Apache Flink to translate Data Science requirements into high-performance, real-time streams. Enable Data Scientists to contribute new features and implement them yourself when needed.

  • Ensure Data Quality, Observability & Integrity: Implement data validation, monitoring, and governance processes to maintain accuracy, consistency, and reliability across all datasets and features in Feature Store.

  • Optimize Pipelines Performance: Identify and eliminate bottlenecks in complex ETL jobs, transforming long-running processes into streamlined, rapid-iteration cycles.

  • Bridge Data Science & Backend Teams: Act as the key link between data science and backend engineering, ensuring seamless data integration and usage across the organization.

  • Explore new Data Sources: Partner with Data Scientists to build custom ingestion logic for unstructured or non-typical data sources, handling the heavy preprocessing needed for experimental research.

  • Evolve the Data Architecture: Maintain and optimize our Data Lake. You’ll help us decide on the future of our storage (e.g., moving toward a Data Lakehouse model) and implement best practices.

  • Work in an International Environment: Join an international, English-speaking team focused on scaling our adtech platform to new heights.

    • Who you are:

  • You have 5+ years’ of software development experience, working on modern data engineering stack. 

  • You have proven experience with Apache Flink for stateful stream processing and real-time feature computation.

  • You have worked extensively with real-time data streaming systems such as Kafka, Kinesis, or Pub/Sub.

  • You have experience with systems handling several TB of data per day and multiple thousand events per second.

  • You know how to identify bottlenecks in data pipelines and you have experience in optimizing them and scaling them up.

  • You have strong Java knowledge, Golang/Python knowledge would be a plus.

  • You have worked closely with Data Scientists on online ML systems with low latency.

  • You know how to move beyond “raw data” to design robust, multi-layered data architectures. You have hands-on experience using dbt to build these layers and can guide us on the best tools and formats to manage them at scale.

  • You know scheduling frameworks such as Airflow / Kubeflow. 

  • You know the concepts of data quality and how to apply them in production.

  • You are familiar with relational and NoSQL databases.

  • You are open to relocating to Hamburg, Germany

  • You have strong problem-solving skills and ability to tackle complex technical challenges.

  • Plus: You have hands-on experience in working with AWS, Terraform and Kubernetes.

  • Plus: You are familiar with the Medallion Architecture and have experience building Semantic Layers for downstream data consumption.

    • Fuel for the Journey: Benefits to Support Your Ambitions
  • Invest in Your Future: Regular feedback and our development program support your growth, helping you expand your skillset and achieve your career goals.
  • Easy Arrival to adjoe: From signing to settling in Hamburg, we’ve got you covered. Need a visa? No problem. Ready to build your new life and career at adjoe in Hamburg? We support every ambition—from learning German to a relocation bonus that helps you settle in and make Hamburg feel like home.
  • Live Your Best Life, at Work and Beyond: We work in a hybrid setup with 3 core office days, plus flexible working hours. Enjoy 30 vacation days, 3 weeks of remote work per year, and free access to an in-house gym with lots of different fitness classes and mental health support through our Employee Assistance Program (EAP).
  • Thrive Where You Work: Enjoy the Alster lake view from our central office with top-notch equipment, fun open spaces, and a large variety of snacks and drinks.
  • Join the Community! Participate in regular team and company events, including hackathons and social gatherings. We work together, and we celebrate together, too.
    • Apply for this job

    Curious About our Recruiting Process?

    The interview process at applike group is seamless, fast, and fun for you! Recruiting is a two-way street, so that’s why our process is designed for both you and us to get to know each other. Our Talent Acquisition team is there to guide you through the process, making sure you will receive the best candidate experience. The process is usually divided into 5 major steps:
    Recruiting FAQs
    Screening Process
    Simply apply with your updated resume, we don’t need any cover letters or additional documents. If you have a relevant portfolio, you can of course share this as well. After reviewing, we will get in touch with you quickly.
    First Interview
    In the first interview you will meet someone from the Talent Acquisition team to get to know more about the company, our culture and the open role.
    Case Study Step
    We designed this step to get a deeper understanding of your skills and also give you some insights into tasks that might be awaiting you in the new role.
    Final Interviews
    In the final interviews you will get the chance to meet you future Lead, Team and also Managing Director to get the full picture of what it could be like working here.
    The offer
    Finally – after clearing all steps successfully, you are going to receive an offer from our side. Congrats, we want you on our team! … and we hope you accept the offer and join us! 🙂

    Tips & Tricks to Nail Your Interviews!

    mail

    Skip cover letters!

    Since we want to keep everything fast and easy for you, we don’t want you to waste time on a cover letter – we would rather take a look at your CV and if it’s a match, we directly invite you to a chat.
    done_all

    Check your equipment

    Test your internet connection, camera, mic, and speakers beforehand. Time for each interview is limited, and we’d like to spend as much of it as possible on getting to know each other. If the interview is online, always have your camera on! It’s way easier to create a meaningful interaction if we also see each other.
    manage_search

    Do some research!

    We will give you all the information about the role & company’s culture, but it’s always nice to see how you perceive us after doing some online detective work 😉
    elevator

    Prepare an elevator pitch

    We will certainly ask you to briefly summarize your work experiences in a short overview. Think of what you’re going to say beforehand so you can fit all of the essential information in 2-3 minutes. Keep the goal of the interview in mind, and make sure everything you say is relevant to the position you’re applying for.
    fact_check

    Structure your answers

    Be specific, but don´t get caught up in details – following the STAR method can help you: Situation (set the scene and give the necessary details of your example), Task (describe what your responsibility was in that situation), Action (explain exactly what steps you took to address it), Result (share what outcomes your actions achieved).
    person_celebrate

    Let your personality shine

    It is a recruiting process, but this doesn’t mean you can’t loosen up and showcase your personality. We are looking for an authentic character and we are open to having some small talk or a funny joke thrown into the mix. This might even show us that you’re a good cultural fit. Remember, we like to have fun!
    live_help

    Be prepared with questions

    At the end of the interview, we will ask you whether you have any questions for us. Use this time to get answers to all your questions or clear out any curiosities. Always have two or three questions prepared, whether about the position specifically or about career development, upcoming projects, or organizational culture.
    event_busy

    Don’t be afraid of rescheduling

    Even if you’ve already scheduled an interview, urgent things might pop up in your schedule or you might not feel fit to attend the interview. We are all human & we treat these situations with empathy. It´s better to reschedule rather than not be 100% up to attend the interview. Simply communicate the change with your TA Manager and we will find a common solution.

    Finding Home Abroad – Relocation Stories

    We’re supporting new colleagues from all over the world to move to Hamburg, Germany – see what they have to share about their relocation experience:
    Read Relocation Article
    “Unlike other companies, justDice/applike was there for me from the beginning. After signing the offer, I got comprehensive support in getting my visa, finding a temporary apartment in Hamburg & covering travel expenses for my whole family. All of this made our relocation significantly easier and more enjoyable.”
    Grigory – justDice
    relocated from Georgia with spouse
    “Relocating to Hamburg with my family of four was a significant undertaking, but applike’s comprehensive support made the transition smooth and stress-free. From arranging our family’s transfer to assisting with residence permits, Applike’s thorough planning and financial backing ensured we felt welcomed and settled in our new home from day one.”
    Roman – Sunday
    relocated from Kazakhstan with spouse and 2 kids
    “Relocating to another country is challenging, but applike group made the process significantly smoother by providing comprehensive support: from handling paperwork to offering a relocation allowance.”
    Min – justtrack
    relocated from Thailand with spouse
    “My relocation process was supposed to be quick and easy yet we stumbled across delays from the embassy. So, the People team was extremely helpful, providing us with all necessary support with documentation, appointments, and processes; all in order to speed up the process and make sure we get to Germany as fast and as easily as possible.”
    Mia – applike group
    relocated from North Macedonia with spouse
    “Moving to Hamburg was a breeze thanks to adjoe/applike. They managed every detail, from flights to accommodation, and their thorough support made me feel valued even before starting my new role. The entire experience was smooth and memorable, making my transition to this beautiful city unforgettable.”
    Kim – adjoe
    relocated from the Philippines

    Recruiting FAQs

    Frequently asked questions
    How long does your recruiting process take?

    We aim to make our recruiting process as fast and efficient as possible, but the duration can vary depending on the role you are applying for. Usually we are really fast, though (less than 4 weeks).

    Can I apply for more than one role?

    Yes, if you see multiple roles open that match your skill set, you can apply for them simultaneously. Our Talent Acquisition team will review your application and contact you about the role that best seems to match your skills. 

    Can I apply for multiple companies within applike group?

    Yes, if you see multiple roles that match your skill set, you can apply for them simultaneously. Our Talent Acquisition team will review your application and contact you about the role that best matches your skills.

    I just handed in my application, what are the next steps?

    Great! Please allow a few days for our team to review your application. We will contact you with the next steps as soon as possible.

    How is AI used for the recruitment process?

    As part of our hiring process, we may use an AI Notetaker tool to transcribe and summarize interviews. This enables our hiring teams to focus fully on candidates and ensures a fair and well-documented selection process.

    This tool joins interviews as a silent participant and generates a transcript and factual notes. Only those directly involved in the hiring process will have access to this data, which is stored securely and deleted after 6 months.

    Candidates are informed in advance, given the option to opt out, and opting out does not impact the outcome of the application.

    How do I know I’m really being contacted by someone from applike group?

    We’ll never ask you for money, fees, or sensitive information (like bank details, tax forms, or credit card numbers) during the hiring process.
    If anything feels off, you can always double-check by reaching out to our Talent Acquisition team at ta@applike-group.com.
    Once you’ve signed your contract, our HR team may request personal details, but only from our official email: hr@applike-group.com.

    How do I know if the job I want to apply to is legitimate?

    To ensure you are applying for a genuine position, we recommend verifying the opening on our official careers pages (applike, adjoe, etc.). If you prefer, feel free to submit your application directly through our site rather than third-party platforms.

    Do I need to be located in Germany to be able to apply for your jobs?

    No, we do provide full visa and relocation support. 

    Do you help with my relocation?

    We do! You can find more information about our relocation support and the succesful relocation of our colleagues here on this website.

    What if I want to relocate together with my family?

    No problem! Our visa and relocation support does also include your partner or kids. (Please be aware that legal marriage is often times a requirement to obtain a partner-visa).

    Can I work remotely?

    If you prefer 100% remote companies, applike is not the right place for you because we strongly believe in face-to-face collaboration. However, we did implement a hybrid working model where we are in the office at least three days a week (Monday, Tuesday, and Thursday) and can work remotely the remaining two days. Additionally, you get three whole weeks per year to work fully remotely if you want.

    What does hybrid working and flexible working hours mean?

    Our hybrid working approach involves being in the office at least three days a week (Monday, Tuesday, and Thursday) and the option to work remotely the remaining two days. Flexible working hours mean that we work Monday-Friday, but do not have fixed working hours. Just make sure to adapt to the rhythm of your team.

    Where is your main-office located?

    The headquarters of the applike group and all its subsidiaries are located in Hamburg, Germany. We do have offices in the US and APAC.

    What is so great about your office?

    Well next to the fact that you are able to see and collaborate with your colleagues face-to-face, we have a super modern office that leave no wishes open: from Drinks & Snack, areas to work away from your desk to a fully equiped gym.

    Can I really bring my dog to the office?

    Yes, you can!

    Couldn’t find the perfect job offer?

    Nevermind! We are always interested to get in touch with new talents.

    Contact us