Dr Kostas Vasilopoulos
AI/ML Engineer @ Pfizer | Econ (Ph.D.)
Summary
Machine Learning Engineer and Ph.D. in Economics building enterprise ML and GenAI platforms in regulated environments. Lead engineering for Pfizer's Data Science & GenAI platform (Dataiku), serving 1,800+ data scientists and 100K+ LLM requests/month across LLM integration, RAG, LLMOps, and platform standards for security and lifecycle management. An economics background brings rigor to decisions under uncertainty: model risk, tradeoffs, and what “good enough” means at scale.
Experience
Senior Manager, Data Science Platform Engineering
June 2026 - PresentPfizer
Thessaloniki, Greece- •Own the engineering strategy and roadmap for Pfizer's enterprise, cloud-native Data Science & GenAI platform (Dataiku), serving 1,800+ data scientists and analysts and hosting a large portfolio of production Python services and web apps
- •Scale LLMOps for 100K+ LLM requests/month, driving cost controls, observability, and access governance across production ML and GenAI workloads
- •Architect enterprise GenAI capabilities (LLM integrations, RAG systems, AI assistants) as reusable platform services that accelerate AI adoption across the organization
- •Establish engineering standards, reusable frameworks, APIs, and self-service tooling that improve developer experience and model lifecycle governance in regulated environments
- •Provide technical leadership across platform, security, data science, and business teams, and manage a direct report
Machine Learning Engineer, Manager
May 2023 - May 2026Pfizer
Thessaloniki, Greece- •Technical owner for integrating and scaling Large Language Models (LLMs) on the enterprise Dataiku platform, solving reliability, performance, and compliance constraints hands-on
- •Designed MLOps execution patterns for model deployment, monitoring, and access control in production, later adopted as platform-wide standards
- •Built reusable platform abstractions and reference implementations for Python services and web apps, driving cross-team adoption of AI capabilities
- •Technical Lead for Ethicara ML: designed and delivered responsible AI solutions aligned with enterprise and regulatory standards
- •Governed platform usage, onboarding, and operations across users, administrators, and engineering teams
Machine Learning Engineer
January 2022 - May 2023OrosDynamics (formerly SophoTree)
United KingdomPromoted from Data Scientist (06.2021 – 01.2022)
- •Tech Lead for EU Horizon 2020 initiatives (Infinitech, AI4PP), owning end-to-end system architecture, delivery, and long-term technical direction
- •Designed and implemented a distributed data collection and processing platform on Kubernetes, horizontally scaling to millions of jobs per day
- •Productionized multiple ML models with autoscaling, microbatching, and runtime optimizations, increasing throughput by 320% and cutting infrastructure costs by 40%
- •As de facto platform owner, defined reusable ML pipelines and CI/CD, observability, and reliability standards adopted across models, services, and teams
- •Built and operated API microservices integrating PostgreSQL, Elasticsearch, and analytics pipelines for real-time and batch workloads
- •Led development and deployment of production NLP pipelines using Spark NLP (classification, sentiment analysis, NER), later reused across document and news processing workloads
Data Scientist
June 2021 - January 2022OrosDynamics (formerly SophoTree)
United Kingdom- •Developed and trained NLP models for large-scale news and document analysis, focusing on classification, sentiment analysis, and entity extraction
- •Extended the platform from structured data to unstructured text, laying the groundwork for the production NLP pipelines later scaled as ML Engineer
Visiting Researcher
July 2021 - July 2022Lancaster University
Lancaster, UK- •Designed and implemented real-time exuberance detection and predictive modeling systems, translating advanced econometric theory into production-grade open-source software (exuber)
- •Delivered 14–150× performance improvements via optimized matrix inversion and numerical methods, enabling real-time processing of large-scale economic datasets
- •Work from the Housing Observatory featured in The Times and used by practitioners, including central banks
Teaching Associate
November 2020 - August 2021Lancaster University
Lancaster, UK- •Taught undergraduate and postgraduate economics courses, consistently receiving outstanding student evaluations
Research Assistant & Graduate Teaching Assistant
October 2016 - October 2020Lancaster University
Lancaster, UK- •Built analytical models and interactive tools for real-time monitoring of UK national and regional housing markets
- •Led web development of the Housing Observatory platform (https://housing-observatory.com/), collaborating with the Federal Reserve Bank of Dallas
- •Authored and maintained 6 open-source R packages (exuber, ivx, uklr, onsr, transx, ihpdr) with 100K+ collective downloads
Education
Ph.D. in Economics
2016-2020Lancaster University
Published research in peer-reviewed journals. Presented work at multiple international conferences and academic workshops.
M.Sc. in Economics, Applied Finance
2014-2016University of Macedonia
B.Sc. in Economics
2009-2014University of Macedonia
AI & Machine Learning
- •Generative AI & Large Language Models (RAG, embeddings, fine-tuning)
- •Natural Language Processing & Text Analytics
- •Production ML Operations & Model Lifecycle
- •Model Evaluation, Monitoring & Drift Detection
Engineering & Infra
- •Programming: Python, R, SQL, JavaScript
- •Distributed Computing & Microservices Architecture
- •Cloud & Containers: AWS, Azure, Docker, Kubernetes
- •Scalability & Performance Optimization
- •Web Development & REST APIs
- •Data Engineering: ElasticSearch, Postgres, Kafka, NoSQL
- •DevOps: Git, Linux, CI/CD Pipelines
Selected Publications
- Vasilopoulos, K., & Tayler, W. (2026). Real Estate and Construction Sector Dynamics over the Business Cycle. Economica. doi:10.1111/ecca.70029
- Vasilopoulos, K., Pavlidis, E., & Martínez-García, E. (2022). Exuber: Recursive Right-Tailed Unit Root Testing with R. Journal of Statistical Software, 103, 1-26.
- Pavlidis, E.G., & Vasilopoulos, K. (2020). Speculative Bubbles in Segmented Markets: Evidence from Chinese Cross-Listed Stocks. Journal of International Money and Finance, 109, 102222.
Software Contributions
- exuber: Econometric Analysis of Explosive Time Series. Published in Journal of Statistical Software (2022).
- ivx: Robust Econometric Inference
- uklr: Client to United Kingdom Land Registry
- onsr: Client for the ONS API
- transx: Transform Univariate Time Series
- ihpdr: Download Data from the International House Price Database
Collective downloads exceed 100,000. The complete package list is available at r-universe.
Awards & Achievements
- Departmental Studentship Award, Lancaster University, 2016-2019
- MSc Scholarship, University of Macedonia (Awarded based on academic excellence)