Kostas Vasilopoulos
AI/ML Engineer @ Pfizer | Econ (Ph.D.)
Professional Summary
I am a Machine Learning Engineer with a Ph.D. in Economics, combining rigorous research methodology with hands-on experience building and operating production ML systems at scale. My background enables me to translate complex analytical and modeling challenges into robust, production-grade engineering solutions.
My focus is on enterprise ML platforms, with expertise in MLOps execution patterns, responsible AI, and horizontally scalable distributed systems. I work on integrating and scaling Large Language Models across enterprise environments, defining platform-wide standards for AI service integration, security, and lifecycle management in regulated settings.
Professional Experience
Pfizer
Machine Learning Engineer, Manager
May 2023 - Present- •Technical owner for integrating and scaling **Large Language Models (LLMs)** across an enterprise platform serving **1,800+ users**, addressing reliability, performance, and compliance constraints
- •Defined and owned platform-wide standards for **AI service integration**, security, and lifecycle management across multiple teams
- •Established and enforced **MLOps** execution patterns for model deployment, monitoring, and access control in production
- •**Technical Lead for Ethicara ML**: Led the design and implementation of responsible and ethical AI solutions to align with enterprise and regulatory standards
- •Acted as a bridge between **users, system administrators, and engineering teams**, governing platform usage, onboarding, and operational processes at scale
- •Drove cross-team adoption of AI capabilities by defining reusable platform abstractions and reference implementations aligned with business needs
Key Technologies:
Python • Machine Learning • LLMs • MLOps • Kubernetes • Cloud Computing
SophoTree
Machine Learning Engineer
January 2022 - May 2023- •**Tech Lead** for SophoTree's EU Horizon 2020 initiatives (**Infinitech, AI4PP**), owning end-to-end system architecture, delivery, and long-term technical direction
- •Owned the end-to-end ML lifecycle and defined reusable pipelines adopted across multiple models and teams
- •Designed and implemented a **distributed data collection and processing platform** on Kubernetes, horizontally scaling to support **millions of jobs per day**
- •Productionized multiple ML models with autoscaling, microbatching, and runtime optimizations, achieving a **320% increase in throughput** and a **40% reduction in infrastructure costs**
- •Built and operated API microservices integrating **PostgreSQL**, **Elasticsearch**, and analytics pipelines to support real-time and batch workloads
- •Acted as de facto **platform owner**, building and operating **API microservices** (**PostgreSQL**, **Elasticsearch**, analytics pipelines) and establishing CI/CD, observability, and reliability standards across services
- •Led development and deployment of production NLP pipelines using **Spark NLP** (classification, sentiment analysis, NER), later reused across document and news processing workloads
Key Technologies:
Python • Kubernetes • PostgreSQL • Elasticsearch • Machine Learning • Microservices • Spark NLP
Data Scientist
June 2021 - January 2022- •Developed and trained NLP models for large-scale news and document analysis, focusing on **classification, sentiment analysis, and entity extraction**
- •Introduced advanced NLP techniques into the platform, expanding analytical capabilities beyond traditional structured data
Key Technologies:
Python • Data Analysis • Machine Learning • NLP • Statistics
Lancaster University
Visiting Researcher
July 2021 - July 2022- •Designed and implemented real-time **exuberance detection and predictive modeling systems**, translating advanced econometric theory into production-grade software
- •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 actively used by practitioners, including **Central Banks**
Key Technologies:
Data Analysis • Statistical Modeling • Research • Economics • Optimization
Teaching Associate
November 2020 - August 2021- •Delivered undergraduate and postgraduate economics courses
- •Consistently received outstanding student evaluations
Key Technologies:
Teaching • Economics • Education
Research Assistant & Graduate Teaching Assistant
October 2016 - October 2020- •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**
Key Technologies:
Data Analysis • Statistical Modeling • Web Development • Economics
Education
Ph.D. in Economics
Lancaster University
2016-2020
M.Sc. in Economics, Applied Finance
University of Macedonia
2014-2016
B.Sc. in Economics
University of Macedonia
2009-2014