Tim is available for hire
Hire TimTim Warr
Verified Expert in Engineering
Machine Learning Engineer and Software Developer
Location
London, United Kingdom
Toptal Member Since
July 2, 2020
Tim is an experienced software developer specializing in data-related projects. With expertise in Python, SQL, and Kotlin, Tim has worked at fast-paced startups and a world-leading technology firm. Combining agility and attention to detail, Tim brings a collaborative mindset to create impactful software solutions.
Portfolio
GResearch
Kotlin, Spring Boot, SQL, Python, Cassandra, C#, Kubernetes, Data Engineering...
Migacore Technologies
XGBoost, Scikit-learn, NumPy, Pandas, Python, Data Science, Data Engineering...
Blockwise Ltd.
MATLAB, Python
Experience
Availability
Full-time
Preferred Environment
Linux, Python, Amazon Web Services (AWS)
The most amazing...
...thing I've built is an algorithmic trading system that deploys live trading strategies across multiple cryptocurrency exchanges.
Work Experience
Data Engineer
2021 - 2022
GResearch
- Designed and built data-intensive applications for ingesting, processing, and serving data in a trading-critical environment.
- Developed automation and tooling that reduced the strategy research phase by days, improving efficiency and time to market.
- Investigated discrepancies in large datasets and visualized findings. Taught teammates how to conduct thorough data investigations.
- Demonstrated exceptional problem-solving skills by supporting the team's comprehensive stack of applications out of hours, effectively debugging and handling critical issues under pressure.
Technologies: Kotlin, Spring Boot, SQL, Python, Cassandra, C#, Kubernetes, Data Engineering, Data Science, PostgreSQL, Microsoft SQL Server, Docker, Docker Compose, Pandas, Polars, REST APIs, Parquet, FastAPI, SQLAlchemy, Data Visualization, Data Analysis, Unit Testing, APIs, Pytest, API Integration, Python API, Back-end, Multithreading, Terraform, Microservices, XML
Machine Learning Engineer
2018 - 2020
Migacore Technologies
- Developed end-to-end machine learning pipelines to predict travel demand and price elasticity in the aviation industry, improving forecasting accuracy by more than 4%.
- Engineered efficient data processing pipelines, handling both structured and unstructured data.
- Built web scrapers to extract event data from unstructured sources, expanding the scope of available data for modeling.
- Designed and implemented models for anomaly detection, demand forecasting, and NLP tasks like sentiment analysis.
- Collaborated closely with the client's project managers and heads of data science to understand requirements, define project scope, and deliver solutions that met their specific needs.
Technologies: XGBoost, Scikit-learn, NumPy, Pandas, Python, Data Science, Data Engineering, Machine Learning, Deep Learning, SQL, PostgreSQL, MongoDB, Amazon Web Services (AWS), Docker, Docker Compose, REST APIs, Flask, SQLAlchemy, Data Visualization, Data Analysis, Unit Testing, APIs, Web Scraping, Python API, API Integration, AWS Lambda, Back-end, Multithreading, Natural Language Processing (NLP), XML
Cryptography Researcher
2017 - 2017
Blockwise Ltd.
- Implemented and tested secure fingerprint recognition models from leading papers.
- Improved an existing model, outperforming state-of-the-art technology on a popular fingerprint recognition task.
- Produced a research report for the company, which was used as the foundation for their white paper.
Technologies: MATLAB, Python
Software Compliance Analyst
2015 - 2016
IBM
- Developed software compliance reports comparing license usage against entitlement.
- Automated report generation, saving 10 – 15 person-hours per week.
- Organized and delivered a training day for 20 colleagues in Brno, Czech Republic.
Technologies: Excel VBA
Experience
Algorithmic Trading System
I led the development of an algorithmic trading system that facilitated the deployment of multiple profitable trading strategies.
ACCOMPLISHMENTS
• Built and deployed robust data pipelines to collect, process, and store level I and II trading data and metadata from various historical and live sources (REST, AWS S3, FTP, and WebSockets).
• Managed the infrastructure, including physical servers and cloud VMs, to ensure smooth system operations.
• Developed a modular framework for defining and deploying trading strategies in live trading environments.
• Created a comprehensive and rigorously tested backtesting framework with performance metrics and visualizations.
• Implemented CI/CD pipelines for automated testing and selective deployments.
• Established monitoring and alerting systems to ensure data integrity and track important financial and risk-related metrics.
I mentored the other two developers throughout the project, conducting thorough code reviews to maintain code quality and consistency.
ACCOMPLISHMENTS
• Built and deployed robust data pipelines to collect, process, and store level I and II trading data and metadata from various historical and live sources (REST, AWS S3, FTP, and WebSockets).
• Managed the infrastructure, including physical servers and cloud VMs, to ensure smooth system operations.
• Developed a modular framework for defining and deploying trading strategies in live trading environments.
• Created a comprehensive and rigorously tested backtesting framework with performance metrics and visualizations.
• Implemented CI/CD pipelines for automated testing and selective deployments.
• Established monitoring and alerting systems to ensure data integrity and track important financial and risk-related metrics.
I mentored the other two developers throughout the project, conducting thorough code reviews to maintain code quality and consistency.
Travel Budgeting Application
An efficient personal finance application for expense management and budgeting, developed using Python (Litestar and SQLAlchemy) and PostgreSQL and hosted on AWS. Users can log transactions manually via a Telegram chatbot, submit them through HTTP/OpenAPI or Google Forms, or import from an open banking CSV file.
The application features a hosted Jupyter Notebook as a minimalistic front end, offering concise summaries, categorized breakdowns, and customizable budgeting views. As the sole developer, I plan to open-source the application in 2023.
The application features a hosted Jupyter Notebook as a minimalistic front end, offering concise summaries, categorized breakdowns, and customizable budgeting views. As the sole developer, I plan to open-source the application in 2023.
Skills
Languages
Python, SQL, XML, Kotlin, C#, Excel VBA
Libraries/APIs
Pandas, NumPy, Scikit-learn, XGBoost, REST APIs, SQLAlchemy, Python API
Tools
Pytest, Docker Compose, MATLAB, Terraform
Paradigms
Data Science, Unit Testing, Microservices
Other
Data Engineering, Data Visualization, Data Analysis, Web Scraping, Machine Learning, Deep Learning, Reinforcement Learning, Polars, FastAPI, Litestar, Parquet, APIs, Natural Language Processing (NLP), WebSockets, Algorithmic Trading, API Integration, Back-end, Multithreading
Frameworks
Flask, Spring Boot
Platforms
Amazon Web Services (AWS), Docker, Kubernetes, AWS Lambda
Storage
PostgreSQL, Microsoft SQL Server, MongoDB, Cassandra
Education
2017 - 2018
Master of Science Degree in Data Science and Machine Learning
University College London - London, United Kingdom
2013 - 2017
Bachelor of Science Degree (Honors) in Mathematical Sciences
University of Bath - Bath, United Kingdom
Certifications
APRIL 2023 - APRIL 2026
AWS Certified Developer
Amazon Web Services
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