Valeriy is available for hire
Hire ValeriyValeriy Karkachev
Verified Expert in Engineering
Software Developer
Antalya, Turkey
Toptal member since August 17, 2022
Bio
Valeriy has been in the software industry for over 25 years, specializing in building high-performance desktop applications utilizing the Microsoft stack. He is a self-motivated, detail-oriented problem solver who guarantees the best possible code quality and performance. Valeriy loves his job and strives for constant improvement, preferring full-time engagement.
Portfolio
KSR Automation
C#, Windows Presentation Foundation (WPF), HTTP, Discord Bots...
Online Freelance Agency
C#, Windows Presentation Foundation (WPF), Windows App Development, C#.NET...
K&A Engineering Consulting
C#, Windows Presentation Foundation (WPF), PostgreSQL, REST, ASP.NET Core...
Experience
Availability
Full-time
Preferred Environment
Windows, C#, Windows Presentation Foundation (WPF), Multithreading, Visual Studio, .NET, SciChart, .NET Core, C#.NET, .NET 6, .NET MAUI, Windows Desktop, Desktop App Development
The most amazing...
...thing I've single-handedly developed from the ground up is an X-ray image acquisition and processing software used by more than 100 clinics worldwide.
Work Experience
Senior Software Engineer
2021 - PRESENT
KSR Automation
- Improved UI legacy to run smoothly and asynchronously.
- Optimized performance to allow thousands of work units to run simultaneously.
- Handled user requests of 4000+ active users and bug reports to improve existing functionality or add new.
- Worked with a project owner to implement the application's performance-critical parts, including complex multithreaded processes, task synchronization, and scheduling.
Technologies: C#, Windows Presentation Foundation (WPF), HTTP, Discord Bots, Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Model View ViewModel (MVVM), Multithreading, Visual Studio, Software Development, ReSharper, REST APIs, API Integration, MVVM Light Toolkit, SQL Server 2016, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), Integration, CSV, SQLite, Dapper, Web Scraping, Data Scraping, Scraping, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end, APIs, MacOS, DLL
Freelance Software Engineer
2013 - 2022
Online Freelance Agency
- Worked on more than 50 projects for over 10,000 hours.
- Maintained top-rated plus status and 100% job success score for nearly nine years.
- Received constantly five-star feedback from the clients.
- Achieved "Top 5% of freelancers in analytical skills" and "Top 5% in C#" badges.
Technologies: C#, Windows Presentation Foundation (WPF), Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Model View ViewModel (MVVM), Microsoft SQL Server, Windows Services, Multithreading, Visual Studio, Software Development, SQL, MySQL, Entity Framework Core, ReSharper, .NET 6, REST APIs, API Integration, MVVM Light Toolkit, SQL Server 2016, PostgreSQL 10, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), Integration, CSV, SQLite, Dapper, Web Scraping, Data Scraping, Scraping, Instagram, Canon EDSDK, SDKs, .NET MAUI, Xamarin, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end, PostgreSQL, CSS, HTML, JavaScript, APIs, MacOS, DLL
Senior Software Engineer
2021 - 2021
K&A Engineering Consulting
- Developed Firefly system using C#, WPF, and PostgreSQL, to help electrical companies maintain their infrastructure.
- Converted legacy UI from WinForms to WPF, improving UI performance.
- Optimized SQL queries to improve database performance.
- Converted the codebase to the latest .NET 6 version.
Technologies: C#, Windows Presentation Foundation (WPF), PostgreSQL, REST, ASP.NET Core, Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Model View ViewModel (MVVM), Microsoft SQL Server, Windows Services, Multithreading, Visual Studio, Software Development, SQL, ReSharper, .NET 6, REST APIs, API Integration, MVVM Light Toolkit, PostgreSQL 10, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), Integration, CSV, SQLite, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end, APIs, DLL
Senior Software Engineer
2018 - 2020
QuantRes
- Developed a set of tools to help traders improve their business.
- Utilized C#, WPF, SQL, high-performance charting, and complex math.
- Used Jira to track tasks and Git as version control.
Technologies: C#, Windows Presentation Foundation (WPF), Telerik WPF, SQL, C++, SciChart, Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Model View ViewModel (MVVM), Microsoft SQL Server, Windows Services, Multithreading, Visual Studio, Software Development, ReSharper, API Integration, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), Integration, CSV, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end, DLL
Senior Software Engineer
2017 - 2019
Medicatech USA
- Developed the company's main product Voyance, the X-ray acquisition software.
- Worked with various UI/UX and X-ray image processing while dialing with X-ray hardware APIs.
- Used the technology stack, including C#, .NET 4.7, WPF, Entity Framework, and PInvoke.
Technologies: C#, Windows Presentation Foundation (WPF), SQL, Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Model View ViewModel (MVVM), Multithreading, Visual Studio, Software Development, ReSharper, API Integration, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), Integration, CSV, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end, MacOS, DLL
Senior Software Engineer
2014 - 2018
Lacima
- Worked on the risk management system called Lacima Analytics, used by multiple power companies across Australia.
- Developed UI/UX using C#, WinForms, and DevExpress components.
- Worked on back-end code and analytical modules applying advanced math and statistics.
- Implemented new functionality and tracked and fixed bugs using Jira as a reporting tool.
Technologies: C#, DevExpress, Entity Framework, Windows Forms (WinForms), SQL, Jira, Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Microsoft SQL Server, Windows Services, Multithreading, Visual Studio, Software Development, C#.NET WinForms, ReSharper, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), CSV, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end, DLL
Tech Lead | Project Manager
2005 - 2010
Altosoft
- Developed mobile software testing platform and conducted code reviews and technical interviewing.
- Implemented critical parts of code related to image and text recognition, such as C# and Visual Studio 2005-2008.
- Acted as a project manager with a team of 20 to 25 people.
Technologies: C#, DevExpress, Telerik, SQL, Jira, Git, Subversion (SVN), Teams, ReSharper, TeamCity, Windows App Development, C#.NET, .NET, Troubleshooting, Root Cause Analysis, XAML, Microsoft SQL Server, Windows Services, Multithreading, Visual Studio, Software Development, C#.NET WinForms, Agile Software Development, Performance Tuning, Object-oriented Design (OOD), CSV, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end
Software Engineer
1999 - 2005
Vibrotek
- Developed industry automation software using Delphi 3 to 7, C, and C#.
- Worked on firmware for smart measurement tools to diagnose and maintain heavy machinery.
- Implemented new functionalities and fixed bugs using the company's proprietary bug tracking system.
Technologies: Delphi 7, C, C#, Windows App Development, Troubleshooting, Root Cause Analysis, Microsoft SQL Server, Visual Studio, Software Development, Performance Tuning, Object-oriented Design (OOD), CSV, SDKs, Windows API, Win32, Windows UI, Windows Desktop, Desktop App Development, Back-end
Experience
QuickBooks | Database Synchronizer
This is a Windows service that tracks changes in QuickBooks Desktop and synchronizes them (two-way) with changes in the proprietary application's database. The service runs 24/7—quite an effort has been made to ensure its reliability.
X-ray Acquisition and Processing Software | Voyance
https://medicatechusa.com/voyance/Voyance Acquisition is an industry-leading complete software suite that delivers a secure and cost-effective way to acquire, view, and share DICOM images. It can communicate with different X-ray sensor hardware and process or enhance images. It also has a set of measurement tools and a patient database.
I joined this project when it was about to fail before release due to poor quality engineering. I rebuilt the application from scratch using C# and WPF.
The software had several released versions and hundreds of licenses sold. Reviews from clinics were excellent, and I believe I left it in great shape.
I joined this project when it was about to fail before release due to poor quality engineering. I rebuilt the application from scratch using C# and WPF.
The software had several released versions and hundreds of licenses sold. Reviews from clinics were excellent, and I believe I left it in great shape.
Cross-platform Desktop CRM Application Built with Avalonia UI
A rich UI desktop application that works on macOS, Windows, and Linux.
It displays tabular data from the database and allows creating, editing, and deleting objects, including client records, jobs completed for clients, job-related images, and more. The application is built using .NET Core 7.0, C#, and Avalonia UI.
It displays tabular data from the database and allows creating, editing, and deleting objects, including client records, jobs completed for clients, job-related images, and more. The application is built using .NET Core 7.0, C#, and Avalonia UI.
Education
1996 - 2001
Master's Degree in System Engineering
Saint Petersburg State Marine Technical University - Saint Petersburg, Russia
Skills
Libraries/APIs
Windows Forms (WinForms), SciChart, Windows API, Entity Framework, QuickBooks API, REST APIs
Tools
Visual Studio, Subversion (SVN), ReSharper, C#.NET WinForms, Jira, Git, TeamCity, Dapper
Languages
C#, C#.NET, XAML, SQL, HTML, Delphi 7, C, C++, CSS, JavaScript
Frameworks
Windows Presentation Foundation (WPF), .NET, .NET Core, MVVM Light Toolkit, Entity Framework Core, .NET MAUI, ASP.NET Core
Paradigms
Object-oriented Design (OOD), Windows App Development, Model View ViewModel (MVVM), Desktop App Development, Agile Software Development, REST
Platforms
Windows, Win32, Windows UI, Windows Desktop, Telerik WPF, Telerik, Xamarin, MacOS
Storage
MySQL, PostgreSQL, SQL Server 2016, Microsoft SQL Server, PostgreSQL 10, SQLite
Other
Multithreading, Software Development, Performance Tuning, Troubleshooting, Root Cause Analysis, Windows Services, .NET 6, CSV, Web Scraping, Data Scraping, Scraping, Back-end, APIs, DLL, IT Systems Engineering, DevExpress, DICOM, Geometry, Image Processing, API Integration, Integration, Instagram, Canon EDSDK, SDKs, Teams, HTTP, Discord Bots, Intuit QuickBooks
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