Kostas Nikolakopoulos
Verified Expert in Engineering
Quant Developer
Athens, Central Athens Regional Unit, Greece
Toptal member since December 18, 2020
Kostas is a data scientist and quantitative analytics specialist focusing on developing predictive models using machine learning techniques. He worked with multiple clients in the financial services sector on projects such as future balance predictions, credit risk modeling, and simulation engines. Kostas has extensive coding experience in Python, R, and C++ and academic background in theoretical physics with a doctoral degree from Sussex University and an MSc degree from Imperial College.
Portfolio
Experience
Availability
Preferred Environment
TensorFlow, Jupyter Notebook, RStudio, PyCharm, Visual Studio
The most amazing...
...performance increase I've implemented brought down the time needed to run a model from days to minutes.
Work Experience
Trading Systems Quant Developer
Emerging Markets Intrinsic LTD
- Developed a Python library to interact with the DAS trader app via HTTP sockets. The library handled messages relating to market data, orders, trades, and positions.
- Developed the strategies for stock day trading. Iterated over various strategy flavors to identify the best performance.
- Developed a user interface to interact with the application. The user interface was web-based, and it could control the program's inputs and browse past results and reports.
LLM Expert via Toptal
Gynisus Inc.
- Worked on parsing large documents in order to extract reporting rules.
- Tried different LLMs to judge their suitability for the problem.
- Tried different modeling approaches to assess their suitability.
AI Engineer
Adam Aerospace Co., LLC
- Developed an MVP using GPT and publicly available data to optimize its performance.
- Experimented and investigated functionalities of LLMs and possible applications to different aspects of the product.
- Maintained the end-to-end infrastructure and monitoring of the AI part of the application.
Capital Market Expert
Visual Candy Systems Limited
- Provided consulting on optimizing algo-trading FX modeling for the client.
- Investigated current performance drivers and optimized feature selection.
- Performed back-testing of historical trades to determine the impact on profit and loss.
AI Developer
Samer Abualsoud
- Developed a trading algorithm based on FX time series using ML/AI techniques.
- Performed back-testing on historical trading data.
- Developed the infrastructure to upload the model online for live trading.
Data Science Consultant
Acuity Trading LTD
- Consulted with the internal team on alternative data applications in financial modeling.
- Prepared training presentations covering various aspects of alternative data usage, including price prediction and portfolio construction.
- Analyzed internal data to create case studies on possible applications in financial modeling.
Lead Quant Developer
SPS Trading
- Developed the dev library for algorithmic crypto trading.
- Designed and developed trading API for quants to interact with the trading systems.
- Implemented and onboarded algorithmic trading models into production.
Machine Learning Engineer
PepsiCo Global - Main
- Developed the Bayesian model for ad allocation using a very long list of features from ad campaigns.
- Trained and maintained the Bayesian model for ad allocation on AWS.
- Performed analysis and presentation of the model's outcomes, specifically feature importance, p-values, and more.
Software and Data Engineer
Reddit, Inc.
- Developed algorithms to optimize advertisement revenue.
- Implemented model changes in Scala to include new features.
- Researched increasing revenue through better budget pacing techniques.
Data Scientist
Grata Inc
- Created an MVP for estimating a company's value from public data.
- Participated in data gathering and building data pipelines.
- Delivered a stand-alone Python app to run a machine-learning model for live valuations.
Python Quantitative Researcher
Tickup (Algo Fund)
- Designed and developed an algorithmic trading platform that connected multiple development components and technologies.
- Onboarded trading strategies from quant workspaces into the trading platform. Performed backtesting and parameter optimization under different scenarios.
- Cleaned, managed, and consolidated data prepared for the go-live version.
Credit Risk Quant
Bank of America Merrill Lynch
- Delivered an IRC/CRM regulatory project dictated by Brexit migration requirements.
- Enhanced aspects of the model to better reflect theoretical requirements and historical behavior. Conducted statistical tests and submitted them to the validation department.
- Improved the performance of the model implementation. Identified the current model's properties, which reduced the execution from days to hours.
Flow Rates Quant
BNP Paribas
- Contributed to the pricing and risk platform of an electronic transformation project.
- Implemented prices and risk-across-rates products such as swaps, bonds, and futures.
- Enhanced the C++ library for pricing and risk calculations.
Quant Developer
Bank of America Merrill Lynch
- Collaborated with the model performance team to backtest the bank models for all asset classes.
- Improved and enhanced the Python codebase and user interface.
- Used Python and C++ coding to simulate risk factors and correlations, applied for calculating profit and loss, XVA, and margins.
Behavioral Modeler
Royal Bank of Scotland
- Led the behavioral modeling team in preparation for separating the Williams & Glyn division of the Royal Bank of Scotland.
- Developed predictive behavioral models for residential mortgages and current or savings accounts. The models' owner was the treasury, using them for the purposes of funds transfer pricing (FTP) and interest rate risk management.
- Coordinated the development of the Python library for the team and developed a web-based GUI for business users to run the models.
Python Quant Modeler
Barclays Bank, PLC
- Developed predictive behavioral models for various portfolios of the bank's investment, corporate, and retail parts using historical time series data; was personally responsible for the residential mortgage book and the corporate term loans book.
- Managed the full lifecycle of the models, from data cleaning to presentation and documentation of results. Performed ad-hoc statistical analyses, scenario analyses, backtesting, and model reviews.
- Contributed to the quant analytics grad training, gaining exposure to all bank departments.
- Performed ad-hoc statistical modeling and statistical data analysis for various projects of the team.
Consultant
d-fine, Ltd.
- Conducted current accounts modeling for a major bank based in Vienna.
- Developed a supervisory mechanism for the EU bank regulator.
- Gained exposure and experience in the large-scale application architecture.
Experience
House Price Prediction
The client can input their property characteristics such as postcode, number of bedrooms, or garden, and get the estimated price. There is also an add-on feature for trend predictions based on property characteristics.
Sports Arbitrage App
Education
Doctoral Degree in Theoretical Physics
University of Sussex - Sussex, UK
Master's Degree in Theoretical Physics
Imperial College London - London, UK
Bachelor's Degree in Physics
Aristotle University of Thessaloniki - Thessaloniki, Greece
Skills
Libraries/APIs
TensorFlow, Scikit-learn, Pandas, NumPy, PyTorch, API Development
Tools
PyCharm, Visual Studio, BigQuery, AWS CLI, ChatGPT
Languages
Python, C++, R, SQL, Java, Go, Python 3, Scala, C#, Perl, C++14
Paradigms
Quantitative Research, ETL, Testing
Platforms
RStudio, Jupyter Notebook, Amazon Web Services (AWS), Docker, Google Cloud Platform (GCP)
Frameworks
Spark, Flask, .NET
Storage
Data Pipelines, Data Lakes, Databases
Industry Expertise
Trading Systems, High-frequency Trading (HFT)
Other
Mathematics, Mathematical Modeling, Statistical Modeling, Statistical Data Analysis, Data Analytics, Statistics, Data Science, Data Modeling, Machine Learning, Artificial Intelligence (AI), Quantitative Analysis, Time Series Analysis, Stan, Correlational Analysis, Simulations, Predictive Modeling, Web Scraping, Bayesian Inference & Modeling, APIs, Data Engineering, Quantitative Modeling, Quantitative Finance, Finance, Distributed Systems, Software Engineering, Numerical Analysis, Algorithms, Back-end Development, Google BigQuery, Machine Learning Operations (MLOps), Deep Learning, Bayesian Statistics, Economics, Natural Language Processing (NLP), Financial Forecasting, Generative Pre-trained Transformers (GPT), Data Scientist, OCR, Writing & Editing, Systematic Trading, Algorithmic Trading, API Design, AWS DevOps, Data Scraping, Fine-tuning, Models, Data Analysis, Dashboards, Capital Markets, Large Language Models (LLMs), Minimum Viable Product (MVP), OpenAI, Data Visualization, Finance APIs, Full-stack, Trading, PDF, Data Extraction, Stock Trading, Financial Software, Principal Component Analysis (PCA), Reinforcement Learning
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring