Ezgi Gurkan, Developer in London, United Kingdom
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Ezgi Gurkan

Verified Expert  in Engineering

ETL Developer

Location
London, United Kingdom
Toptal Member Since
March 24, 2021

Ezgi is a senior developer with 12 years of experience in data technologies. He has proven expertise in architecting and implementing complex data projects involving ETL operations, data pipelines, data warehousing, and data modeling. He can quickly learn new technologies on his own initiative and apply best practice principles such as CI/CD, automated testing, and more. Ezgi has led small teams, mentored junior developers, and can communicate complicated topics with non-technical stakeholders.

Portfolio

CIBC
Python, SQL, Spark, Spark SQL, Databricks, C#, .NET Core, MongoDB...
Marshall Wace Asset Management
SQL, Data Build Tool (dbt), Snowflake, Microsoft Power BI, SSAS Tabular, DAX...
NHS Property Services
T-SQL (Transact-SQL), Azure SQL Databases, Azure Data Lake, Azure Logic Apps...

Experience

Availability

Full-time

Preferred Environment

Visual Studio, Visual Studio Code (VS Code), Azure, SQL, Snowflake, .NET, Amazon Web Services (AWS), Python

The most amazing...

...project I've developed was a profitable high-frequency trading app for executing market-making and arbitrage strategies on crypto exchanges such as Coinbase.

Work Experience

Senior Data Engineer

2023 - 2024
CIBC
  • Developed data ingestion processes from various sources such as APIs, NoSQL databases, and Parquet/JSON/CSV files into Databricks delta tables.
  • Designed a distributed data quality framework where multiple applications report DQ issues to a web service using a central repository of rules.
  • Built ETL processes and dashboards for various internal projects.
Technologies: Python, SQL, Spark, Spark SQL, Databricks, C#, .NET Core, MongoDB, Azure Databricks, PySpark

Senior Data Engineer

2020 - 2023
Marshall Wace Asset Management
  • Redesigned a legacy data application that calculates performance and risk metrics of the company's funds. Scoped requirements, built data pipelines, modeled complex data relationships, and managed stakeholders in various teams and senior management.
  • Built the process to calculate the company's financial performance to value the company for its shareholders.
  • Developed an ETL process that moved hundreds of billions of rows of data from on-prem databases into cloud warehouses using a multithreaded Python application.
  • Worked with ESG analysts to build ESG-related metrics for each fund, which were used by the portfolio manager, risk, and quant teams.
Technologies: SQL, Data Build Tool (dbt), Snowflake, Microsoft Power BI, SSAS Tabular, DAX, Apache Airflow, Bitbucket, Kubernetes, Helm, .NET Core, Data Engineering, Data Warehousing, Data Warehouse Design, ETL, Software Engineering, DevOps, GitOps, Python, Amazon Web Services (AWS), C#, Linux, Data Pipelines, Microsoft SQL Server, Data Modeling, Data Quality, Data Architecture, Data Analytics, PostgreSQL, Query Optimization

Data Engineer

2019 - 2020
NHS Property Services
  • Developed fault-tolerant processes to move on-prem business data to the cloud, with automated data quality checks.
  • Replaced a legacy reporting system for the finance team with a data warehouse solution that saved the team several days of effort every month, provided automated reconciliation capabilities, and improved data accuracy.
  • Introduced DevOps to the data team by implementing version control, determining the branching strategy, building automated tests, and setting up CI/CD pipelines. Trained developers on the tools and processes.
  • Acted as interim team lead during the absence of the manager due to health issues, helping with architectural decisions.
Technologies: T-SQL (Transact-SQL), Azure SQL Databases, Azure Data Lake, Azure Logic Apps, Azure Data Factory, Azure Blobs, Azure DevOps, Microsoft Power BI, Windows PowerShell, Data Warehousing, Data Warehouse Design, ETL, Reporting, DevOps, Data Engineering, Cloud Native, Data Lakes, Data Pipelines, Azure SQL, Microsoft SQL Server, Data Modeling, Data Quality, Data Architecture, Data Analytics

Software Developer

2018 - 2018
Barclays
  • Maintained an application to redress mis-sold financial products, automating the process of remedying millions of customers' issues.
  • Implemented a new continuous integration pipeline for the application's deployment.
  • Improved the source control process with automated scripts to save developers' time and effort.
Technologies: SQL, TeamCity, Windows PowerShell, Software Engineering, DevOps, Microsoft SQL Server, Python

BI Developer

2017 - 2018
Just
  • Developed and managed internal data solutions such as data warehouses, ETL processes, cubes, and reports, including a metadata-driven data store.
  • Built a single-customer view for the company—helping the managers get a better understanding of how clients were interacting with different parts of the business.
  • Implemented CI/CD processes for a variety of complex BI solutions, including a metadata-driven data store, ETL packages, and reporting solutions.
Technologies: SQL, SQL Server Integration Services (SSIS), SQL Server Reporting Services (SSRS), Microsoft Power BI, Windows PowerShell, TFS, .NET, Data Warehouse Design, Data Warehousing, ETL, Data Engineering, DevOps, Reporting, C#, Data Visualization, Data Wrangling, Data Pipelines, Microsoft SQL Server, Data Modeling, Data Quality, Data Architecture, Data Analytics

BI Consultant

2013 - 2017
MI-GSO
  • Delivered data analytics and migration solutions for leading blue-chip organizations in a variety of sectors, including financial services, manufacturing, public, energy, and aerospace. Clients included CLS, Nationwide, Sellafield, BP and TfL.
  • Helped in pre-sales activities, filling RFQs for complex tenders/bids, doing demos, and defining requirements with new clients.
  • Built Pcubed's internal data warehouse for its global CRM/ERP system, feeding data into its parent company.
  • Mentored junior developers to help them improve their technical skills and prepare for delivering projects to clients.
Technologies: SQL, SQL Server Reporting Services (SSRS), SQL Server Integration Services (SSIS), Microsoft Power BI, SharePoint, Microsoft Dynamics NAV, .NET, Windows PowerShell, Data Warehousing, Data Warehouse Design, ETL, Data Engineering, Reporting, Azure, C#, Data Visualization, Data Wrangling, Data Pipelines, C#.NET, Microsoft SQL Server, Data Modeling, Dashboards

Commodity ETF Trader

2012 - 2012
IMC
  • Handled a portfolio of commodity ETFs and the currency hedging of the ETF desk, driving millions of profit every month.
  • Priced securities and analyzed trade and market movements to determine the best trading strategies to increase profits and minimize risks.
  • Increased my desk's profits by 6% through developing trading and hedging strategies to beat competitors and take advantage of market opportunities.
Technologies: Trading, High-frequency Trading (HFT), Arbitrage, Financial Markets

Web Developer

2010 - 2010
OpenBet
  • Developed the back-end logic for betting and gambling websites such as William Hill and Ladbrokes.
  • Implemented both the front and back end of the clients' websites from web design requirements.
  • Automated the analysis of error logs from various servers, saving the team a significant amount of time and reducing the likelihood of errors going unnoticed.
Technologies: HTML, CSS, JavaScript, Tcl/Tk, SQL, Linux

Billing Optimisation for Management Consultancy

I spearheaded the automation of time utilization tracking for the consultants of a large management consultancy to maximize billing rates, which also provided standardized global reporting across offices worldwide.

This work was initially performed manually by a senior HR employee, taking up almost his entire time and causing numerous data accuracy and consistency issues. I devised a solution to completely automate the process and convinced senior HR, finance, and IT stakeholders, including the CTO, to try the new approach.

The solution involved a data warehouse, ETL processes pulling data from several business applications, and complex reports incorporating all the business logic.

The output of this process was required by the parent company of the consultancy, which owned numerous other consultancies. We were the first to automate this process and were asked to replicate it in other subsidiaries. Unfortunately, I left the company soon after and didn't see how the project would progress.

Fund Perfomance Reporting for Hedge Fund

I redesigned a legacy data application that calculates performance and risk metrics of the company's funds, which had strict regulatory requirements. The new solution saved the responsible team a considerable amount of manual work every month, increased data accuracy, and introduced flexibility to allow end-users to configure different outputs they need.

This was the largest project I had ever done in my career and took more than three years. With intermittent help from various teams, we scoped requirements, built data pipelines, modeled complex data relationships, implemented statistical metrics, developed automated data quality processes, and managed stakeholders in five-six teams, as well as senior management.

The technical solution involved a data warehouse-type solution in Snowflake using dbt, various automated processes in Python, and a custom front-end application. Almost every member of the data engineering team was pulled into this project at various points, with me being responsible for the overall design. It was a great collaborative effort.

Adtech SaaS Application

http://www.venilio.com
As the technical co-founder of a startup, I built a SaaS application that allowed users to optimize their digital marketing budgets across different ad platforms, such as Facebook, Instagram, Twitter, and LinkedIn.

High-frequency Trading for Cryptocurrencies

I developed a profitable high-frequency trading application for cryptocurrencies that executed market-making and arbitrage strategies on large exchanges, such as Coinbase, using price and volume information.

This was a performance-driven, multi-threaded application using the FIX protocol and Level 3 market data.

I used TDD, continuous integration, and automated testing processes during its development and deployment.

SaaS Application

As the sole founder of a startup, I developed a SaaS application to provide DevOps and BI capabilities for SharePoint Online and Project Online, saving clients hundreds of hours of consultant time.

My work also included managing a team of freelance web developers to implement the application's front end. In addition, I formed partnerships with two consultancies to better understand client requirements and help with sales.

Languages

SQL, Snowflake, Python, C++, Java, C#, Python 3, T-SQL (Transact-SQL), HTML, CSS, JavaScript, Tcl/Tk, C#.NET

Paradigms

ETL, Business Intelligence (BI), Database Design, DevOps, Distributed Computing, Azure DevOps

Storage

SQL Server Integration Services (SSIS), Data Pipelines, Microsoft SQL Server, Azure SQL, Databases, SSAS Tabular, Azure SQL Databases, Azure Blobs, SQL Server Reporting Services (SSRS), MongoDB, Data Lakes, PostgreSQL, MySQL

Other

Data Build Tool (dbt), Data Warehousing, Data Engineering, Data Warehouse Design, Data Modeling, Data Analysis, Software Engineering, Reporting, Data Visualization, Machine Learning, Computer Vision, Artificial Intelligence (AI), Evolutionary Algorithms, Statistics, Econometrics, Derivatives, Corporate Finance, Portfolio Management, Mergers & Acquisitions (M&A), Financial Markets, DAX, Azure Data Lake, Azure Data Factory, Trading, Arbitrage, FIX Protocol, GitOps, Data Wrangling, Dashboards, Data Quality, Data Architecture, Data Analytics, APIs, Stakeholder Management, Solution Design, Business Requirements, Azure Databricks, Query Optimization

Tools

Microsoft Power BI, Apache Airflow, MATLAB, Visual Studio, Bitbucket, Helm, Azure Logic Apps, Amazon SageMaker, TeamCity, TFS, Microsoft Dynamics NAV, GitHub, Spark SQL

Platforms

Azure, Windows, Kubernetes, SharePoint, Linux, Amazon Web Services (AWS), Cloud Native, Visual Studio Code (VS Code), Databricks

Frameworks

.NET Core, Windows PowerShell, Angular, .NET, Spark

Libraries/APIs

TensorFlow, Stripe, PySpark

Industry Expertise

Project Management, Accounting, High-frequency Trading (HFT)

2010 - 2011

Master's Degree in Finance

Durham Business School - Durham, UK

2008 - 2009

Master's Degree in Artificial Intelligence

University of Southampton - Southampton, UK

2005 - 2008

Bachelor's Degree in Computer Science with Artificial Intelligence

University of Southampton - Southampton, UK

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