Senior Data Scientist Defense (w/m/d)

About us

Zenjob is an AI-powered flexible staffing platform that has efficiently connected companies and temporary workers since 2015. Companies use our platform to book ready-to-work staff in real time, while students use our app to find part-time jobs that conveniently fit around their studies. Over 40,000 students and 1,000 partner companies from logistics, retail, and hospitality in all major German cities share our belief that good work is not a coincidence. It is the result of innovative technology and genuine commitment. Good work starts here.

The role

Data is at the core of Zenjob’s marketplace, and we’re looking for a collaborative, forward-thinking Head of Analytics & Data Science to guide our next chapter. In this role, you will lead and mature our data and analytics function, helping the team unlock actionable insights and scale their impact across the company. You will help us integrate Artificial Intelligence further into our everyday work—both in how we optimize our platform and how we improve our internal workflows. If you are a pragmatic leader who loves mentoring developing talent, solving marketplace puzzles, and exploring practical AI applications, we’d love to meet you.

What you'll do

• Nurture and Grow the Team:
  Coach and develop our team of Data Scientists and Analysts. You will foster a healthy, collaborative culture rooted in continuous learning, best practices, and practical business impact.
• Integrate AI into Everyday Work:
  Guide the team in adopting modern AI tools and methodologies to improve our daily workflows, while helping identify smart opportunities to leverage AI.
• Drive Pragmatic Execution:
  Manage the roadmap for data initiatives. You will keep a steady delivery pace, ensuring the team's output translates into clear, measurable value for Zenjob.
• Collaborate Across Teams:
  Partner closely with Data, Engineering and Business stakeholders to ensure we are building a collaborative, reliable, and accessible data ecosystem.
• Focus on What Matters:
  Help the team prioritize high-impact initiatives, ensuring we are solving mission-critical business problems rather than getting lost in the noise.

What you bring

• Team Leadership Experience:
  A proven track record of managing and developing data professionals (analysts and/or data scientists) in a fast-paced environment.
• An Open Mind Toward AI:
  Curiosity and practical experience with modern AI tools, with a clear view of how to use them to automate workflows and enhance analytical capabilities.
• Marketplace Intuition:
  Prior experience or a deep understanding of two-sided marketplace dynamics (supply, demand, and matching optimization) is highly valued.
• Strong Business Translation:
  The ability to bridge the gap between technical data work and business reality, turning complex analysis into simple, actionable insights for stakeholders.
• Solid Technical Foundations:
  A strong background in data modeling, analytical methodologies, and experimentation, combined with a highly pragmatic approach to problem-solving.
• Great Communication Skills:
  An empathetic communication style that allows you to influence stakeholders, build trust, and bring people along on the data journey.

What we offer

• Innovative mission:
  Together we create something new. Work in a dynamic set-up where you learn a lot and your every idea is heard.
• Unique team spirit
  : We can rely on each other blindly and celebrate all successes together as a team.
• Vacation
  : Recreation and further education is important, which is why we offer 28 days of paid vacation (increased by 1 day for every 2 calendar years of service with us, up to a maximum of 30 days), 1 day of special leave for community service, 5 days of paid educational leave, and the possibility of unpaid leave
• Hybrid working model
  : We love our brand new office in Prenzlauer Berg. But sometimes you need a little more flexibility. Zenjob’s flexible working model combines the best of both worlds, so you can work remotely up to 2 days / week (1 day, during the first 6 months, so we can guarantee you the best onboarding).
• Dog-lover
  : If you have a dog, feel free to bring it with you. We don’t bite and always have a bowl of water in our range of drinks
• Personal growth
  : Ongoing focus on your personal development (annual training budget of EUR 1000, mentoring opportunities, constant career development conversations)
• Healthy mind in a healthy body:
  With us you will receive a 30 EUR Urban Sports Club grant to keep you fit. In addition, we have a small sports room in the office ourselves.
• Always mobile:
  You will receive EUR 40 credit per month for NAVIT, a sustainable mobility tool for public transport, bike sharing and much more.
• Legendary Events:
  Quarterly team events, winter and summer parties, budget for birthdays and anniversaries of our employees

If this sounds good, then we’d love to find out more about you! Apply and send in your application.

🎥 Watch our Office Tour video.

We invite you to visit our careers page, follow our LinkedIn page and connect with us on Instagram.

We are proud to be an equal opportunity employer. We are committed to judging every qualified individual on their ability, regardless of age, gender identity, ethnicity, sexual orientation, disability status, or religion. There is no need to add your photo and age to the application.

At Instructure
, we believe in the power of people to grow and succeed throughout their lives. Our goal is to amplify that power by creating intuitive products that simplify learning and personal development, facilitate meaningful relationships, and inspire people to go further in their education and careers.

We do this by giving smart, creative, passionate people opportunities to create awesome. And that's where you come in:

Our AI team is where a lot of that gets built: applying advanced AI to real problems in learning, and turning research into product capabilities that educators and students use every day.

We're looking for a Senior Machine Learning Engineer to build and own the learner models behind our mastery and progression capabilities. You'll design the models, build the pipelines that train and score them, and own their quality once they're running in production.

You'll partner with our learning scientists on what these models should measure, and with our infrastructure team on deployment and operations.

What You'll Do

• Design and build learner models, including knowledge tracing and longitudinal approaches, that power mastery and progression features surfaced to learners and educators
• Shape the data foundation for learner modeling: define which signals matter, and build the datasets your models depend on
• Translate mastery and progression definitions into model targets and evaluation criteria, working with learning scientists and product partners
• Build estimation and scoring approaches that hold up on sparse, noisy, and evolving behavioral data
• Own your models in production: training and scoring pipelines, testing, versioning, and monitoring quality once they're live
• Explain model behavior, assumptions, and limitations clearly to product, engineering, and learning partners

What You'll Need

• Six or more years in applied machine learning, machine learning engineering, or applied research, with ownership of models shipped into real products
• Depth in at least one of: sequence modeling, latent-variable or probabilistic modeling, temporal modeling, Bayesian methods, or calibration of model outputs, applied to data that changes over time
• Strong Python and production engineering skills: you write the pipelines that train and score your models, and you've shipped models that run on a schedule and serve predictions to real users
• Strong evaluation instincts around calibration, uncertainty, stability, fairness, interpretability, and validation strategy

It Would Be a Bonus If You Had

• Experience with recommender systems, user-state modeling, or personalization at scale
• Experience with knowledge tracing, psychometrics, educational measurement, or adaptive learning systems
• Experience combining structured knowledge representations, such as skills, standards, or concept graphs, with learner models
• Experience designing experiments or observational validation strategies to test whether a model reflects reality

Onsite Collaboration Requirement:
This role requires working onsite on Tuesday and Wednesday, with Thursday strongly encouraged as part of our company’s in-person collaboration model.

Why Join Us

Join us and help shape the future of education by turning cutting-edge AI into reliable product capabilities.

At Instructure, we're on a mission to help educators and students learn together, anytime, anywhere, and however works best. You'll join our research-driven team tackling education's biggest challenges with cutting-edge technology.

We value diversity, creativity, and passion, and invest in our teams through mentorship, hack weeks, internal conferences, and a culture where innovation thrives. Here, you'll have the chance to build the next generation of LMS features that make a real impact on students and teachers, and do it in a collaborative, supportive environment that encourages experimentation and growth.

Get in on all the awesome at Instructure!
We offer competitive, meaningful benefits in every country where we operate. While they vary by location, here's a general idea of what you can expect:

• Competitive compensation, plus all full-time employees participate in our ownership program - because everyone should have a stake in our success.
• Flexible work culture. Our remote, hybrid and in-office collaboration spaces vary by role, team and location.
• Generous time off, including local holidays and our annual “Dim the Lights” period in late December, when teams are encouraged to step back and recharge based on departmental needs.
• Comprehensive wellness programs and mental health support
• Learning and development resources, including professional development tools and tuition reimbursement, to support your growth
• The technology and tools you need to do your best work
• Motivosity employee recognition program
• A culture rooted in inclusivity, support, and meaningful connection

We believe in hiring great people and treating them right. The more diverse we are, the better our ideas and outcomes.

Instructure is an Equal Opportunity Employer. We comply with applicable employment and anti-discrimination laws in every country where we operate.

All employees must pass a background check as part of the hiring process. To help protect our teams and systems, we’ve implemented identity verification measures. Candidates may be asked to verify their legal name, current physical location, and provide a valid contact number and residential address, in accordance with local data privacy laws.

Any attempt to misrepresent personal or professional information will result in disqualification.

Let’s be unstoppable together!
Circana is a leading provider of technology, AI, and data solutions for consumer packaged goods companies, manufacturers, and retailers. Our predictive analytics and Liquid Data® platform help clients measure market share, uncover consumer behavior, and drive growth—powered by six decades of expertise and an expansive, high-quality data set.

At Circana, we are fueled by our passion for continuous learning and growth, we seek and share feedback freely, and we celebrate victories both big and small in an environment that is flexible and accommodating to our work and personal lives.  We’re a global company dedicated to fostering inclusivity and belonging. We value and celebrate the unique experiences, cultures, and viewpoints that each individual brings. By embracing a wide range of backgrounds, skills, expertise, and beyond, we create a stronger, more innovative environment for our employees, clients, and communities. With us, you can always bring your full self to work.  Join our inclusive, committed team to be a challenger, own outcomes, and stay curious together. Circana is proud to be Certified™ by Great Place To Work®. This prestigious award is based entirely on what current employees say about their experience working at Circana. Learn more at www.circana.com.

Role Overview
This position sits within the Media Data Scientist Team and focuses on product Development. The key objective is to develop data science code, supporting Circana’s Media & Product Innovation practices. You will support data science aspects of the end to end media product development cycle. This includes exploratory data analysis, developing and implementing the end-to-end modeling platform, statistical methodology development and empirical experiment design. You will also work with big databases from different sources and assemble them into analysis and insights exploration ready format.

Job Responsibilities

• Apply and design best-in-class methodologies and statistical algorithms to answer business questions.
• Build and maintain modeling engines for Circana analytics platforms using various tools, such as Python, SQL, Spark, etc.
• Utilize advanced computations/statistics and machine learning/AI methodologies.
• Partner with cross-functional teams (e.g., Technology, Product, Commercial, etc.) to build analytical solutions for some of the largest retailers and manufacturers in the world, utilizing granular data at scale.
• Work directly with clients including the top advertising platforms to gather detailed requirements and communicate results.
• Document and present methodologies and research findings to internal and external stakeholders
• Manage and mentor junior data scientists, guide them in problem-solving and help them develop their technical skills.

Requirements

• Postgraduate degree in Statistics, Econometrics or related quantitative field; Masters or PhD preferred
• 6+ years’ experience of Python/R development. Strong proficiency for statistical analysis, data visualization, and statistical modeling. Familiarity with packages like Pandas, NumPy, Matplotlib in Python, dplyr, ggplot2, tidyr in R.
• SQL: Ability to write complex queries, perform joins, aggregations, subqueries, window functions, and optimize queries for performance.
• Data extraction and manipulation: Skill in retrieving and integrating data from multiple sources and formats.
• Deep understanding of statistical concepts, including descriptive statistics, inferential statistics, hypothesis testing (t-tests, ANOVA, chi-squared), regression analysis (linear, logistic), time series analysis, A/B testing.
• Solid understanding of various Machine Learning and AI algorithms
• Able to build and convey impactful insights drawing from multiple data sources. Skilled at explaining technical subject matter to non-technical audiences.
• Nice to have: Previous experience in Marketing Mix Modeling and other Media measurement techniques.

Circana Behaviors
Beyond technical skills, experience, and role-specific attributes, these shared behaviors are fundamental to our culture and success. We seek individuals who consistently demonstrate and champion these behaviors in their daily work:

• Stay Curious: Being hungry to learn and grow, always asking the big questions.
• Seek Clarity: Embracing complexity to create clarity and inspire action.
• Own the Outcome: Being accountable for decisions and taking ownership of our choices.
• Center on the Client: Relentlessly adding value for our customers.
• Be a Challenger: Never complacent, always striving for continuous improvement.
• Champion Inclusivity: Fostering trust in relationships engaging with empathy, respect, and integrity.
• Commit to each other: Contributing to making Circana a great place to work for everyone.

Location:
This position can be located in the following area(s): Remote, Greece