Senior Data Scientist (mfd) Remote (based in Romania)

A small piece of paper with numbers that have the power to change a life forever! Okay... lets replace the paper with an app and one person with 500000 monthly users. This is our business!

Your Mission

As Senior Data Scientist (m/f/d) - Build decisioning and optimization models that measurably improve how we allocate budgets choose placements prioritize experiments and personalize user communication - while meeting production-grade engineering standards (reliable pipelines monitoring and safe deployment). This role exists to turn data into automated or semi-automated actions across marketing and adjacent business functions.

Your Tasks & Responsibilities

• Build prediction models (e.g. conversion/CPA forecasts propensity/LTV churn risk creative or placement performance signals) with strong validation and calibration.
  

• Build decision policies: rules constrained optimization (and bandits where appropriate) for allocation placements pacing creative rotation and personalization.
  

• Design and analyze experiments/incrementality tests to validate models and policies (not just offline metrics).
  

• Productionize with MLE-quality: reproducible pipelines versioning monitoring alerting and safe rollback; partner closely with Engineering/Data.
  

• Translate outputs into decision-ready guidance and clear trade-offs (expected impact uncertainty constraints).
  

• Maintain concise documentation of models/policies data dependencies and decision logic.
  

Your Goals in This Role

• Within 1 month: Deliver a first working Decisioning MVP (one high-impact optimization use case) that produces actionable recommendations on a weekly cadence with documented assumptions and evaluation.
  

• Within 2 months: Have 2 decision models/rule systems running in production-like operation (scheduled monitored versioned) influencing real decisions (budget/placement/creative/personalization).
  

• Within 34 months: Launch a personalization or allocation model that is validated via experimentation (holdout/A-B) and shows measurable lift vs. baseline policy.

• Within 6 months: Operate a repeatable pipeline for continuous learning (re-training/refresh monitoring guardrails) and ship at least 4 high-impact decisioning/optimization improvements used by teams.
  
  

Your Key Competencies

Must-have

• Strong applied ML statistics (modeling evaluation calibration leakage prevention uncertainty-aware thinking).
  

• Experience building decisioning/optimization (constraints policies experimentation-driven iteration; bandits a plus).
  

• Solid engineering fundamentals: clean code testing mindset reproducible pipelines monitoring/alerting and secure handling of data/secrets.
  

• Strong data skills: SQL Python feature engineering data QA and working with warehouses/lakes.
  

• Ability to run end-to-end delivery: problem framing model/policy validation rollout measurement.

Nice-to-have

• Ads/marketing domain (DSPs/walled gardens attribution/MMP concepts) and/or personalization (CRM/push).
  

• Causal inference / uplift modeling experience.

• High ownership: ships measures iteratesdoesnt stop at analysis done.
  

• Strong stakeholder communication: explains trade-offs uncertainty and rollout risks clearly.
  

• Pragmatic prioritization under ambiguity; focuses on highest ROI levers first.
  

• Calm structured execution (production-quality over clever hacks).
  

• Collaborative mindset with Engineering/Data/Marketing/Finance.

Your Impact in This Role

• Higher ROI and fewer wrong moves through evidence-based allocation and optimization.
  

• Faster learning cycles via experimentation-backed model iteration.
  

• Reduced manual decision work through reliable decisioning systems and guardrails.
  

• A scalable foundation for personalization and automation beyond marketing.

Your Background Education & Experience

• Masters Degree in Computer Science Data Science Statistics Mathematics Econometrics or Business Informatics (or equivalent proven skill).
  

• 510 years experience in Data Science / Applied ML with at least one example of models/policies used in production.
  

• Proven experience working with engineers on production constraints (monitoring reliability safe deployment).

What we offer you:

Remuneration & work-life balance:

• Competitive salary and trust-based working hours.

• Private health insurance.

• Generous training budget.

• 2 extraordinary team events (4 days) per year.

• Meal benefit.

Communication & trust:

• Open honest and direct communication. Your ideas are welcome!

• A feedback meeting every quarter to help us grow together.

• We encourage innovation and are open to new ideas that push the boundaries.

Modern working:

• Everything you need for your daily work: MacBook monitor headphones and more.

Individual training:

• One training day per month and a generous training budget for your personal development.

Buddy program:

• An experienced team member will support you from day one to help you get started.

The team

• We are a colorful bunch from different nations and backgrounds. We dont distinguish by religion gender age marital status... For us the focus is on what you can do!

Our values:

MAKE IT HAPPEN

• Drive results - Own the problem the goal and the outcome through self-organization and decisions backed by data

• Speak up with courage - Challenge ideas and raise issues directly when it matters

• Getting things done - Be pragmatic keep momentum and bring the energy

• Deliver quality impact - Ship solutions that move our mission and strategic goals forward

WIN TOGETHER

• Communicate openly and respectfully - Be transparent assume positive intent and set aside own ego when interacting with others

• Help others win - Proactively share knowledge time and strengths in an interdisciplinary set-up

• Work across cultures - Learn from others perspectives and actively refine own style for trust-based collaboration in a diverse team

• Bring team spirit - Create moments of joy and belonging that fuel big outcomes together

SHAPE THE FUTURE

• Experiment to learn - Run tests measure outcomes treat mistakes as an invitation to learn and adapt insights into action

• Spot opportunities - Stay close to customers and market trends to identify whats next

• Build user-first innovation - Deliver trustworthy data-driven solutions and services that set the bar

• Grow yourself - Challenge and reflect on the way you work seek feedback and keep developing your skills
  
  
  Sound like you