Jakub Daszkiewicz, Developer in Gdańsk, Poland
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Jakub Daszkiewicz

Verified Expert  in Engineering

Data Engineer and Developer

Gdańsk, Poland
Toptal Member Since
November 24, 2020

Jakub is passionate about the intersection of finance—including cryptocurrencies—and computer domains. Thanks to this expertise, he has worked with several large banks in the UK, Austria, and Poland to optimize processes and reduce their time from hours to minutes by tuning large SQL queries. He has spent most of his professional life in development and customer support. Jakub thoroughly enjoys digging into database-related data (logs, locks, and query plans) to identify what can be approved.


PostgreSQL, Qlik Sense, QlikView, MySQL, IBM Db2, Informatica ETL...
Scalability, Sed, AWK, Oracle SQL, Objective-C, Python, Pandas, SQL...




Preferred Environment

Unix, Windows, Eclipse, IntelliJ IDEA, Linux

The most amazing...

...thing I've developed is a system, including the whole database model, to manage investment and pension funds in one of the largest custodian banks in Poland.

Work Experience

Data Engineer

2022 - 2023
Pfizer - PGS Operations Insights
  • Migrated all ETL jobs from Amazon Redshift to Snowflake during the migration period in May 2023.
  • Tuned all processes in the PostgreSQL capacity planner database.
  • Implemented several AWK tools to facilitate access to UDH data for business users.
Technologies: Data Engineering

Senior Developer and BI Specialist

2021 - 2022
  • Refactored the whole Aurora (MySQL) database, which was not performing well enough to work with the web application processing hundreds of millions of rows.
  • Optimized huge data warehouse DB2 queries, querying and joining tables with billions of rows.
  • Reorganized ETL pipelines, ensuring availability and continuity of the data pipeline process.
  • Created new fact and dimension tables for newly added KPIs using the Kimball methodology.
Technologies: PostgreSQL, Qlik Sense, QlikView, MySQL, IBM Db2, Informatica ETL, Data Engineering

Senior Lead Developer

2010 - 2020
  • Defined data structure and relationships to represent regulatory-related banking requirements imposed on banks after the financial crisis in 2008.
  • Defined ETL pipelines to enable importing data from external systems, so users do not need to enter it manually.
  • Improved the integration tests environment by more than 300%.
  • Integrated all types of market data from the external system into the new system, including quotes, zero and yield curves, volatility surfaces, and swaption cubes.
  • Resolved several performance-related database issues where complex processes over time increased to several hours. Understood the financial domain and code and suggested changes to fix it.
  • Gathered business users' requirements and implemented an entirely new functionality and micro-hedging requested by our customer, Austria Bank.
  • Implemented regulatory regulations around Basel III—risk-weighted assets.
Technologies: Scalability, Sed, AWK, Oracle SQL, Objective-C, Python, Pandas, SQL, Microsoft SQL Server

Lead Developer

2007 - 2010
  • Resolved several performance-related database issues for customers in the product.
  • Improved database performance for the largest customer in the UK. Suggested several changes to the structures of some indexes, modified some queries in the system, and sped up the system.
  • Integrated external systems with the product. During the integration, a lot of ETL needed to be done. Bash, sed, and AWK were used intensively.
Technologies: SQL, Oracle, JavaScriptCore, ETL

Senior Lead Developer

1999 - 2007
  • Designed the whole database model for the largest custodian bank in Poland to manage investment and pension funds.
  • Implemented modules to calculate NAV and other related indicators.
  • Implemented a module to manage and control various limits imposed on investment funds.
  • Created Crystal Reports reports generating documents required by regulatory institutions.
  • Developed a module to extract transaction data from incoming SWIFT messages.
Technologies: Database Design, IBM Informix, Data Engineering

Fusion Risk

An Objective-C based application with the UI in Java Swing to manage liquidity and credit risk of retail banks. Due to the financial crisis in 2008, there were many new regulations added regarding how banks should manage their assets. I was working as a senior developer in the team, working closely with business analysts, to implement various regulations revolving around IFRS 9, SA-CCR, and also FRTB.
The system was used to calculate in real-time the current risk exposure of all the branches in a bank. It was very flexible. The system was using embedded domain-specific language allowing banks to specify very detailed, customized processing allowing discounting and amortizing all the cash flows of each and every financial transaction registered in the system.


A Java/JSP system to manage investment and pension funds in the largest custodian bank in Poland. The database was Informix 9. The system needed to support 3 selling ways of fund's assets: FIFO, LIFO, and average cost. The system imported the transactional data from the main banking book in the bank. Apart from this, it was able to process 52x/53x SWIFT messages send to/from the bank.
1999 - 2000

Specialized Master's Degree in Finance Management and Banking Relations

École Supérieure de Commerce - Rouen, France

1999 - 2000

Master of Science Degree in Finance and Banking

University of Gdansk - Gdansk, Poland

1993 - 1998

Master's Degree in Computer Science

Technical University of Gdansk - Gdansk, Poland


DA-100: Analyzing and Visualizing Data with Power BI



Azure Administrator AZ-103



Oracle Certified Professional, Java EE 5 Business Component Developer



FRM - Financial Risk Manager (GARP ID: 1023320)



Oracle Certified Programmer Java 11





Qlik Sense, Informatica ETL, Microsoft Power BI


ETL, Scrum, Database Design


Sed, AWK, SQL, Python, Objective-C, Bash Script


Oracle SQL, PostgreSQL, Microsoft SQL Server, IBM Informix, MySQL, IBM Db2


Linux, Oracle, Windows, Unix, QlikView




Data Engineering, IFRS 9, Scalability, DAX

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