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Jani Järvinen
Verified Expert in Engineering
Software Developer
Vantaa, Finland
Toptal member since July 29, 2021
Bio
Jani is an experienced and certified software development professional with over 20 years of experience in Microsoft technologies, cloud services, and web application development. In addition, Jani is well aware of system security, DevOps, project management, and databases. Jani has also authored six software development books as well as worked as a trainer in various technologies.
Portfolio
Freelance
Visual Studio, C#, XML, Electronic Data Interchange (EDI), SOAP...
Freelance
ASP.NET, ASP.NET MVC, ASP.NET Web API, Azure, Visual Studio, C#...
Freelance
ASP.NET, Azure, Microsoft SQL Server, Azure SQL, Visual Studio, C#, LINQ...
Experience
- C# - 20 years
- Visual Studio - 20 years
- C#.NET - 19 years
- Microsoft SQL Server - 18 years
- ASP.NET MVC - 12 years
- Web API - 10 years
- .NET Core - 5 years
- .NET 5 - 2 years
Work Experience
Senior Lead Developer
2019 - PRESENT
Freelance
- Took over the in-house implementation of a large-scale integration solution using XML, CSV, EDI, and SOAP.
- Managed a small team of developers and testers using Monday.com project management software.
- Set up a production environment for future automatic deployment in a DevOps manner.
Technologies: Visual Studio, C#, XML, Electronic Data Interchange (EDI), SOAP, Microsoft SQL Server, NServiceBus, RabbitMQ, Monday.com, DevOps, .NET 5, Unit Testing, Data Integration, System Integration Testing (SIT), Technical Leadership, APIs, SQL, Blazor, CSS, HTML, Microsoft Stack, Windows UI, XSD, XML Web Services, Integration
Senior Developer
2012 - 2021
Freelance
- Designed, architected, and developed and .NET (C#/VB.NET) web application using ASP.NET to serve the public in Finland; this included designing and implementing a 200GB database using SQL Server.
- Managed a team of six members, including in-house developers.
- Set up the production environment and launched the application to the public.
Technologies: ASP.NET, ASP.NET MVC, ASP.NET Web API, Azure, Visual Studio, C#, Visual Basic .NET (VB.NET), Microsoft SQL Server, Jira, .NET 5, APIs, Technical Leadership, .NET, JavaScript, SQL, Blazor, CSS, HTML, Microsoft Stack, Telerik, Windows UI, XSD, XML Web Services, Integration
Senior Developer
2016 - 2020
Freelance
- Architected and developed with a team a web-based MES application for a meat processing plant.
- Tracked requirements and bugs using Azure DevOps servers while operating under an Agile Scrum methodology; also managed a team of 20 developers and testers.
- Installed the first working version into production for the client.
Technologies: ASP.NET, Azure, Microsoft SQL Server, Azure SQL, Visual Studio, C#, LINQ, Entity Framework, .NET Core, .NET, JavaScript
Senior Developer
2017 - 2019
Freelance
- Developed a public ASP.NET Web API application using C# and SQL Server for a complex video surveillance system. The Public API can be used to control the system and view realtime video streams.
- Designed the application architecture and initial version; later versions were developed by in-house developers.
- Automated the system testing process using PowerShell and Microsoft Hyper-V; also developed the automatic testing scripts.
Technologies: ASP.NET Web API, OAuth 2, C#, Microsoft SQL Server
Senior Developer
2016 - 2019
Freelance
- Developed a UWP desktop client application and an ASP.NET Web REST API to support the client. The application is used to monitor, record, and control manufacturing equipment and store issues within them for maintenance use.
- Managed a small team of developers and testers; also worked with application requirements using GitHub tasks.
- Launched the application using a private Windows store for five office locations.
Technologies: Visual Studio, Universal Windows Platform (UWP), UI Design, ASP.NET Web API, Microsoft SQL Server, Azure, C#, Git, GitHub, APIs, Technical Leadership
Back-end Developer
2010 - 2014
Freelance
- Developed an ASP.NET and WinForms combination application for a steel manufacturing plant.
- Implemented optimization logic for source material management.
- Designed an SQL Server database to support about 10 million rows for storing and reporting plant data.
Technologies: Visual Studio, C#, ASP.NET, Windows Forms (WinForms), Entity Framework, Microsoft SQL Server, Web API
Back-end Developer
2008 - 2011
Freelance
- Developed real-time advertising solutions to select and run ads on a television channel. The ad data was stored on an SQL Server database, and retrieved using stored procedures.
- Integrated the solution to a television control system using TCP/IP.
- Managed requirements using Jira and set up a version control system using Microsoft Team Foundation Server (TFS).
Technologies: Visual Studio, C#, Microsoft SQL Server, Stored Procedure
Lead Developer
2005 - 2008
Freelance
- Developed a Windows desktop application for managing airplane and helicopter snags, warehouse and inventory management, and preventive maintenance.
- Managed project requirements and issues with Atlassian Jira.
- Migrated existing snag data from Microsoft Access database to SQL Server.
Technologies: Visual Studio, C#, Windows Forms (WinForms), Microsoft SQL Server
Lead Developer
2002 - 2005
Freelance
- Developed a product management system and a webshop for a retail company using newly-released C# and ASP.NET. The solution consisted of a desktop product management application and a webshop with ASP.NET.
- Implemented CSV and XML pricing information import and export functionality.
- Set up the production environment using Windows Server 2000 and IIS.
- Created a monitoring system for the webshop that checks to see if it's online and working correctly.
Technologies: Visual Studio, C#, ASP.NET, Microsoft SQL Server, IIS
Lead Developer
1998 - 2002
Freelance
- Developed an integration application using XML and simple object access protocol (SOAP); also designed the integration architecture and managed a small team of developers.
- Built a simple monitoring user interface for the solution to quickly find integration errors and asses performance.
- Wrote a Finnish book about XML/SOAP integrations based on my experience in this project and others.
Technologies: Delphi, Microsoft SQL Server, XML, SOAP
Lead Developer
1996 - 1998
Freelance
- Developed a Windows desktop accounting app for small businesses and home users; my work included architecting the app, creating the UI and the accounting logic, and designed the SQL database to support the data.
- Composed simple marketing material for the application and coded an installer utility for the application; also created the release build and helped to press 20,000 copies of CDs for the application.
- Helped to support the application and develop patch releases and continued development until 1998, when the development was handed over to an in-house developer.
Technologies: C++, Delphi, Microsoft SQL Server
Project History
Public Web API for a Real-time Video Management System
I built an ASP.NET and C#-based real-time video management system using SQL Server as the database. I also designed both the architecture and a public Web API and implemented the first version.
The application is available in 40 countries.
The application is available in 40 countries.
Education
1996 - 2000
Associate Degree in Computer Science
University of Helsinki - Helsinki, Finland
Certifications
JANUARY 2012 - PRESENT
Certified Microsoft Technical Specialist
Microsoft
Skills
Libraries/APIs
Web API, Entity Framework, LINQ, NServiceBus, REST APIs, Windows Forms (WinForms)
Tools
Visual Studio, Jira, Git, GitHub, RabbitMQ
Languages
C#, C#.NET, XML, SQL, JavaScript, CSS, HTML, XSD, Delphi, Stored Procedure, Visual Basic .NET (VB.NET), C++
Frameworks
ASP.NET MVC, .NET Core, .NET 5, ASP.NET Web API, ASP.NET, .NET, OAuth 2, Blazor
Paradigms
Unit Testing, Design Patterns, UI Design, DevOps
Storage
Azure SQL Databases, Data Integration, Azure SQL, Microsoft SQL Server
Platforms
Windows, Azure, Universal Windows Platform (UWP), Telerik, Windows UI
Other
Software Development, System Integration Testing (SIT), Architecture, Microsoft Stack, XML Web Services, Integration, SOAP, IIS, Monday.com, Technical Leadership, APIs, Electronic Data Interchange (EDI)
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