Karol Szymanski, Developer in Gdańsk, Poland
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Karol Szymanski

Verified Expert  in Engineering

Back-end Developer

Location
Gdańsk, Poland
Toptal Member Since
November 16, 2021

Karol is a .NET developer with 15 years of experience in all software development cycles. He excels in requirements gathering, estimates, features description and breakdown, architecture design, development, CI/CD, production deployment, support, and troubleshooting. Karol is focused on understanding the client's needs and recommending the best solutions.

Portfolio

EPAM Systems
Azure DevOps, Angular, ASP.NET, DotTrace, Git, Jenkins, LINQ, Visual Studio...
EPAM Systems
Angular, ASP.NET, DotTrace, Git, Jenkins, LINQ, Visual Studio...
POSTDATA
.NET, SQL, Jira, Jenkins, Mercurial, Visual Studio...

Experience

Availability

Part-time

Preferred Environment

Windows, Visual Studio, Octopus Deploy, Azure DevOps, Windows PowerShell, .NET, SQL, Git

The most amazing...

...thing I've developed is an algorithm that calculates when the wind turbines will cast flickering shadows on nearby houses to stop them and avoid human epilepsy.

Work Experience

Lead Software Engineer

2019 - 2021
EPAM Systems
  • Built a wind turbine simulator to enable performance testing, allowing development teams to test the software on simulated inputs rather than connecting to actual physical sensors.
  • Created and configured a virtual environment—as part of the CI/CD/CT pipeline—for performance tests resembling a large wind farm.
  • Integrated all the products with SonarQube to improve the quality.
  • Oversaw the solution architecture of all products and implementation of the key components.
Technologies: Azure DevOps, Angular, ASP.NET, DotTrace, Git, Jenkins, LINQ, Visual Studio, SQL, Visual Studio Code (VS Code), Bamboo, Octopus Deploy, Jira, TypeScript, ReSharper, Windows PowerShell, VMware vSphere, .NET, HTML, AutoMapper, Draw.io, NUnit, Moq, Serilog, Unity, Topshelf, OPC Server, OPC Data Access, DevOps, C#, C#.NET, APIs, Architecture, Refactoring, Code Review, Full-stack, Microsoft SQL Server, Microservices, Microservices Architecture, REST APIs, JSON, .NET Core, SOLID Principles, KISS, YAGNI, Gang of Four (GOF) Design Patterns, Software Deployment, Software Design Patterns, Source Code Review, Pull Requests, CSS, JavaScript

Senior Software Engineer

2018 - 2019
EPAM Systems
  • Implemented a low-level ESXi API—while developing the FEX project—that allowed the customer to use the vSphere ESXi license, which costs €940 per year instead of the standard ESXi API that requires the vCenter subscription of €5,665 per year.
  • Collected all the design requirements while communicating with the client.
  • Implemented the entire FEX project enabling the customer to pay less for the licenses.
  • Conducted the demos for stakeholders and made all adjustments to the project based on their comments.
Technologies: Angular, ASP.NET, DotTrace, Git, Jenkins, LINQ, Visual Studio, Visual Studio Code (VS Code), Bamboo, Octopus Deploy, Jira, TypeScript, ReSharper, Windows PowerShell, VMware vSphere, VMware ESXi, .NET, HTML, VBScript, cURL Command Line Tool, LiteDB, NoSQL, Draw.io, NUnit, Moq, Serilog, Unity, Topshelf, DevOps, Object-oriented Programming (OOP), Test-driven Development (TDD), C#, C#.NET, Architecture, Microservices, Microservices Architecture, APIs, JSON, REST APIs, SOLID Principles, KISS, YAGNI, Gang of Four (GOF) Design Patterns, Software Design Patterns, Software Deployment, Refactoring, Full-stack, CSS, JavaScript

Senior Software Engineer

2015 - 2018
POSTDATA
  • Created a module that processes 1 million transfers per day and optimized its performance to work on old servers with HDD disks.
  • Developed a tool that calculates the UI test coverage for WinForms applications, which won the company's award for the most innovative tool of the year.
  • Designed the database structures for most of the new modules.
  • Acted as a mentor for less experienced programmers.
  • Implemented the money laundering detection service with notifications and reports.
Technologies: .NET, SQL, Jira, Jenkins, Mercurial, Visual Studio, Visual Studio Code (VS Code), ReSharper, Octopus Deploy, DotTrace, Entity Framework, LINQ, ASP.NET, Windows Presentation Foundation (WPF), Windows Forms (WinForms), Angular, TypeScript, Managed Extensibility Framework (MEF), NUnit, Moq, UML, PGP

Software Development Specialist

2006 - 2015
POSTDATA
  • Conducted internal training in the field of test-driven development.
  • Fixed production bugs based on the service-level agreement (SLA) and defined three levels of the criticality of errors with different maximum repair times.
  • Estimated and implemented new features provided by the business analyst.
Technologies: .NET, SQL, Jira, Mercurial, Visual Studio, ReSharper, Entity Framework, DotTrace, LINQ, ASP.NET, Windows Forms (WinForms), NUnit, Moq, JSON, PGP, UML, UML Diagrams

Bat Protection System

BPS is a system with control logic that detects when different bat species fly near wind turbines and stops turbines to prevent the rotating blades from killing bats.

As part of the development team, my task was to discover the scope, break down the features, deliver solution architecture and estimation, design the key components, identify gaps in the created solution, and lead the development team to deliver a high-quality code. After completing the code development, I coordinated the system installation in wind farms with the release manager.

Shadow Flicker Control System

The system detects when rotating turbine blades cast flickering shadows on nearby houses and stops the turbines to avoid human epilepsy. After developing the algorithm, it received an international certificate.

I was involved in defining the scope, features, and solution architecture. I also estimated and designed the critical components while identifying gaps in the prepared solution. As the development team leader, I delivered high-quality code that enabled the installation of the system.

Ice Control System

The system with control logic detects ice on turbine blades using various detection methods and performs actions to remove it. The system is designed for safety reasons to get rid of ice in a controlled manner and reduce the risk of ice debris being thrown in random directions that could damage nearby infrastructure or kill people.

I led the development team that determined the scope, broke down the features, designed the solution architecture, and performed the estimations. We also created the components, identified the gaps, and wrote the high-quality code to install the system in the wind farms that the release manager coordinated.

FEX Project

The application creates virtual machines containing different versions of Windows and Linux, installs software developed by a customer in a specific version, performs integration tests, and obtains results. The application was used internally to test whether the software works in different environments or recreate production conditions to fix bugs. As a result, it only required a few clicks on the user interface to create a fully functioning environment.

I was the only developer creating this application and oversaw the following activities:
• gathering project requirements from the customer;
• organizing meetings with subject matter experts;
• presenting demos to the customer;
• performing manual functional testing;
• performing integration between Octopus, VMware ESXi, and HP UFT; and
• creating a mechanism to record errors from Octopus, VMware ESXi, and HP UFT in one place.
2002 - 2006

Bachelor's Degree in Computer Science

Koszalin University of Technology - Koszalin, Poland

APRIL 2017 - PRESENT

Developing Entity Framework

Altkom Academia

APRIL 2017 - PRESENT

Angular 2

infoShare Academy

JANUARY 2017 - PRESENT

Programming in WPF 4.5

NobleProg

MAY 2016 - PRESENT

In-Memory OLTP and In-memory Analytics Concepts

SQLDay Conference by PLUSSG

MARCH 2016 - PRESENT

Test-driven Development

Custom Training Solutions

MAY 2014 - PRESENT

Creating Efficient Database Applications

Betacom

MAY 2013 - PRESENT

AGILE in Company

Allegro

AUGUST 2011 - PRESENT

MS2543: Core Web Application Technologies with Microsoft Visual Studio 2005

Microsoft

MAY 2011 - PRESENT

Enterprise Architect—Tool for Modelling and Managing IT Projects

Erudis Process Management

FEBRUARY 2011 - PRESENT

UX, Ergonomics, and Usability in Designing WWW Interface

POSTDATA

OCTOBER 2010 - PRESENT

MS6317: Upgrading Your SQL Server 2000 Database Admin (DBA) Skills to SQL Server 2008 DBA Skills

Microsoft

JULY 2008 - PRESENT

MS2310: Developing Microsoft ASP.NET Web Applications using Visual Studio .NET

Microsoft

MARCH 2008 - PRESENT

Technical Workshops SQL Server 2008

Comp

OCTOBER 2007 - PRESENT

MS2784: Tuning and Optimizing Queries Using Microsoft SQL Server 2005

Microsoft

MAY 2007 - PRESENT

MS2548: Core Distributed Application Development with Microsoft Visual Studio 2005

Microsoft

DECEMBER 2006 - PRESENT

MS2124: Programming with C#

Microsoft

Libraries/APIs

Windows Forms (WinForms), Moq, Entity Framework, LINQ, Managed Extensibility Framework (MEF), AutoMapper, REST APIs

Tools

Visual Studio, ReSharper, DotTrace, VMware vSphere, Git, Jira, Jenkins, Mercurial, Bamboo, cURL Command Line Tool, Draw.io

Frameworks

.NET, NUnit, Windows PowerShell, ASP.NET, Scaled Agile Framework (SAFe), .NET Core, Windows Presentation Foundation (WPF), Angular, Unity, Topshelf

Languages

SQL, C#, C#.NET, TypeScript, UML, HTML, VBScript, XML, CSS, JavaScript

Paradigms

Test-driven Development (TDD), DevOps, Object-oriented Programming (OOP), KISS, YAGNI, Refactoring, Azure DevOps, Scrum, Waterfall Development, Microservices, Microservices Architecture, Gang of Four (GOF) Design Patterns

Storage

JSON, Microsoft SQL Server, NoSQL, LiteDB

Platforms

Windows, Software Design Patterns, Visual Studio Code (VS Code)

Other

Octopus Deploy, OPC Server, PGP, SOLID Principles, Code Review, Pull Requests, Full-stack, VMware ESXi, Source Code Review, Architecture, APIs, Software Deployment, Serilog, OPC Data Access, Enterprise Architecture, User Experience (UX), HP UFT, UML Diagrams

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