Senior Java/Spring Backend Engineer

Company Description Who We Are Cint is a pioneer in research technology (ResTech). Our customers use the Cint platform to post questions and get answers from real people to build business strategies, confidently publish research, accurately measure the impact of digital advertising, and more. The Cint platform is built on a programmatic marketplace, which is the world’s largest, with nearly 300 million respondents in over 150 countries who consent to sharing their opinions, motivations, and behaviours. We are feeding the world’s curiosity! Job Description The Role We're hiring several Backend Engineers for the Synthetic Data Platform team. This is a greenfield project, an exciting new market and a key part of Cint’s 2026 product strategy. You will build everything that connects the Synthetic Data platform to the outside world: the integration with the Cint Exchange, and the integrations with survey hosting platforms that bring survey data into the platform in the first place. Without the data flowing in and the products flowing out, none of the modelling matters. The products you enable include: Survey Augmentation: filling missing responses to surveysAudience Profiling: predicting respondent characteristics from signals we haveAgentic Insights: answering a client’s research questions using insights from existing data The Team You'll join our Synthetic Data team in Prague, working alongside the AI/ML engineers who own augmentation and profile modelling, the data science team, and a product manager who owns the Synthetic Data roadmap. Customer pilots are already running, and feedback from those pilots shapes the roadmap. Qualifications What You'll Do: Connect Synthetic Data to the Cint Exchange: Design and build the services and APIs that plug the platform into Cint's marketplace, so synthetic data products reach the buyers and surveys already running there.Build integrations with survey hosting platforms: Own the integrations with third-party survey platforms that let us ingest questionnaires and response data into the Synthetic Data platform, from first API call to a production connector our customers can rely on.Own the ingestion path end to end: Build the pipelines that normalise wildly different questionnaire and response formats into something our models can learn from, and keep the data quality, consent and privacy guarantees our respondents and clients expect.Run it in production: Own throughput, latency, cost, monitoring and reliability of the platform's integration and ingestion surfaces.Work closely with the AI/ML engineers: They own the training pipelines and inference services; you own how data gets in and how the results get out. Expect to help each other across that line.Leverage AI tooling: Use Claude Code and agentic programming tools where appropriate. What You Bring Outstanding problem-solving and analytical skills3+ years of hands-on professional backend software development experience, preferably in JavaStrong experience with Data Structures and AlgorithmsProven experience as a Software Developer in their previous rolesExperience building and operating production services, APIs and data pipelines at scaleFamiliarity in SQL, knowledge of Databricks is a plusYou enjoy pushing the limits of your knowledge and experience every dayYou own your conclusions and are comfortable presenting them and shaping outcomesNice to have: AWS, k8s, Spring, Kafka/KinesisNice to have: exposure to AI/ML development, model libraries (XGBoost, LightGBM, CatBoost or similar) or LLMs — you don't need to build the models, but curiosity about them helps Additional Information Working at Cint Prague-First, Europe-Friendly: Our preferred base is Prague, alongside our existing AI/ML team. Remote work from Spain or the UK is also possible, as these are the markets where we have entities.AI-Native Engineering: We're rolling out Claude Code and modern agentic tooling across engineering. You'll use it daily, not as a novelty, but as a force multiplier for the complex problems that matter.High Autonomy: We trust our engineers to make sound decisions and own their work end-to-end.Global Impact: Your work powers a marketplace used by millions of people worldwide.Modern Tech Stack: We usually build our services using the latest Python tooling and FastAPI, dockerize them and deploy with CI/CD to K8s in AWS. We keep the code on GitHub.Company Hardware: Cint provides a laptop (Win/Linux/Mac) and accessories, and a height adjustable desk at the Pankrác officeBenefits Include:Office in Prague (Pankrác) but full remote possible25 days of vacation, unlimited sick daysPension fund contribution, Edenred meal vouchers Our Values Collaboration is our superpower We uncover rich perspectives across the worldSuccess happens togetherWe deliver across borders. Innovation is in our blood We’re pioneers in our industryOur curiosity is insatiableWe bring the best ideas to life. We Do What We Say We’re accountable for our work and actionsExcellence comes as standardWe’re open, honest and kind, always. We are caring We learn from each other’s experiencesStop and listen; every opinion mattersWe embrace diversity, equity and inclusion. More About Cint We’re proud to be recognised in Newsweek’s 2025 Global Top 100 Most Loved Workplaces®, reflecting our commitment to a culture of trust, respect, and employee growth. In June 2021, Cint acquired Berlin-based GapFish – the world’s largest ISO certified online panel community in the DACH region – and in January 2022, completed the acquisition of US-based Lucid – a programmatic research technology platform that provides access to first-party survey data in over 110 countries. Cint Group AB (publ), listed on Nasdaq Stockholm, this growth has made Cint a strong global platform with teams across its many global offices, including Stockholm, London, New York, New Orleans, Singapore, Tokyo and Sydney. (www.cint.com) Additionally, in a world of AI, we want our candidates to understand our approach to the use of AI during the interview and hiring process, so we'd appreciate you reading our AI usage guide.