Senior Data Scientist
Experian is hiring a Senior Data Scientist in Sofia, Bulgaria. Level rates it ; you can apply on Level.
AI in this role
Experian is a global data and technology company, powering opportunities for people and businesses around the world. We operate across a range of markets, from financial services to healthcare, automotive, agribusiness, insurance, and many more. Experian invests in people and new advanced technologies to unlock the power of data. We have an amazing team of 25,200 people in 32 countries.
As a Senior Data Scientist you will lead research, development and client-focused innovation across our fraud analytics portfolio by creating solutions that strengthen fraud detection, digital trust and risk decisioning across markets. You will evaluate and integrate data assets while balancing multiple concurrent projects, anticipating risks and deliver outcomes. You will invent machine learning, graph, behavioural and GenAI methods to structured and unstructured data; and convert prototypes into reusable capabilities on the Ascend platform.
The product scope includes fraud analytics and decisioning solutions, unified digital intelligence, device fingerprinting and behavioural intelligence, trade-delete and credit-washing analytics, GenAI fraud assistants.
You will report to Director of Data Science and GenAI.
What you'll do:
- Analyze large-scale fraud, credit, device, behavioral and digital-interaction data to identify risk and trust signals.
- Develop fraud models, scores, attributes, device profiles and graph-based capabilities for AFS and related solutions.
- Apply advanced machine learning, graph analytics, deep learning and GenAI methods to complex fraud challenges.
- Evaluate and measure value of new data assets.
- Build scalable data pipelines, reusable analytical tools, automation templates and production-ready solutions on Ascend.
- Validate model performance, stability, fairness, explainability and growth.
- Lead analytical and productization workstreams.
- Apply advanced algorithms to business problems and move solutions from research or prototype into production or client use.
- Translate technical findings into recommendations.
- Partner across multiple geographically distributed teams.
- Mentor colleagues, share expertise and promote responsible AI and reproducible practices.
- Maintain knowledge of fraud trends, digital intelligence, regulation, GenAI and latest analytical technologies.
- Measure benefits and explain trade-offs.
What you'll bring:
- 5–7+ years of relevant experience in data science, AI, predictive modeling or advanced analytics, including ownership of complex, hands-on innovation and client-focused projects.
- 7+ years of experience developing data and automation pipelines and transitioning analytical prototypes into monitored, scalable production solutions.
- Grasp of probability, statistical inference, optimization, linear algebra and calculus
- Understanding of when and how to apply regression, machine learning, AI, deep learning, clustering, gradient boosting, graph algorithms, anomaly and pattern detection, and Gen AI.
- Command of model validation, including cross-validation, regularization, Bayesian methods, in-sample versus out-of-sample testing, statistical significance tests and Monte Carlo simulation.
- Write near-production-level Python code; experience with PySpark and distributed data processing.
- Knowledge in modern ML and deep-learning tooling and LLM and agent-based development frameworks.
- Understanding of large-scale data technologies, cloud platforms, NoSQL and graph databases, time-series data and tools for unstructured information.
- Knowledge of fraud risk, identity, device fingerprinting, digital or behavioral intelligence, credit-washing analytics, credit risk, fraud graphs or fraud strategy optimization.
- Understanding of model governance, responsible AI, explainability, privacy, security and regulatory considerations relevant to fraud and digital-interaction data.
- Interest and experience mentoring colleagues and providing technical leadership.
- Advanced technical/quantitative degree or equivalent experience.
- Fluent English
What you will get:
- Personal Development - career pathway for professional growth supported by learning and development programs and unlimited access to online educational training courses, learning materials and books.
- Work environment - excellent work conditions with friendly environment, recognized team spirit, and fun and quality recreation time.
- Social benefit package including life insurance, food vouchers, additional health insurance, monthly flex allowance and internet coverage, corporate discounts, marriage and childbirth / adoption allowance, Multisport card, Sharesave plan, Employee assistance program, а birthday gift and many other benefits!
- Work-life balance - 25 days paid vacation, 1 additional day off for your birthday and extra 3 paid days for participation in Social responsibility event.
- Opportunity for Flexible working hours and Home Office.
Experian is an Equal opportunity employer. Everyone can succeed at Experian and bring their whole self to work, irrespective of their gender, ethnicity, religion, colour, sexuality, physical ability or age. If you have a disability or special need that requires accommodation, please let us know at the earliest opportunity.
#LI-Hybrid
This is a hybrid remote/in-office role.
Recruitment Fraud Awareness - Experian's recruitment process is conducted only through authorised channels. Recruitment communications will only be sent from an @experian.com email address. Experian will never ask candidates to make any payment as part of an application, interview, assessment, onboarding, or recruitment process. To apply for roles or verify opportunities, please visit experian.com/careers.
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How we rate this
Senior Data Scientist at Experian rates 89 out of 100 for how much of the daily work is AI. That makes it Builds AI (AI Level 4 of 4). The level is about AI in the job, not seniority.
Builds AI. The job is building AI systems.
- ●●●● Builds AI80 to 100
- ●●●○ Works on AI60 to 79
- ●●○○ Uses AI40 to 59
- ●○○○ Little AI0 to 39
Levels come from how often the tools, models and workflows of the role are named in the posting itself. Open the description and count.
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- How would you decide a model or AI system is ready to ship?
- Tell me about a time a model underperformed in production. How did you find out, and what did you change?
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- List these exact terms on your resume: AI Safety. An applicant tracking system matches the wording, not the idea.
- Attach one line of real, concrete experience to at least one of them — a tool named with nothing behind it rarely survives a human read.
- Lead with what you built, trained or shipped — this role is judged on the AI system itself, not the tools around it.
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