C# (.NET) Startup Success: The Story of a Business Process Automation Platform

C# (.NET) Startup Success: The Story of FlowBiz

When three former colleagues from a large IT company decided to create their own product in 2021, the choice of programming language seemed obvious. C# and the .NET platform became the foundation of the FlowBiz startup, which today automates document flow for 5,000 companies across Russia. We tell the story of how a technical decision shaped the fate of the business.

Why C# (.NET)?

The founders of FlowBiz — Sergey, Anna, and Dmitry — had 10 years of experience developing enterprise systems in C#. When choosing the stack, they were guided by three factors:

• Enterprise heritage: .NET Framework has proven its reliability in the banking and government sectors, which is critical for a B2B product.
• Quick start: ASP.NET Core and Entity Framework allowed them to build an MVP in 4 months.
• Performance: C# provides high-speed database operations and multithreading.

First Round: From Idea to Prototype

The startup began in a small coworking space. A team of 5 people wrote code in C# 10, using .NET 6. The key task was to create an electronic document management (EDM) module compatible with 1C and SAP. Thanks to the rich .NET ecosystem — the ClosedXML library for Excel and DocX for Word — integration took only 3 weeks.

Within 6 months, FlowBiz had its first 50 clients. "We beat our competitors on Python and Java precisely because of stability: not a single document was lost in the system," recalls technical director Dmitry.

Crisis and Scaling

By the end of 2022, the number of users had reached 2,000, but the servers were starting to slow down. The solution was a migration to .NET 7 with Cloud Native support. The team rewrote the core for minimal memory consumption and introduced microservices:

• Service A (C#): processing incoming documents (RabbitMQ queues).
• Service B (C#): report generation (SignalR for real-time).
• Service C (Python, auxiliary): machine learning for scan recognition.

The combination of languages proved successful: C# handled the business logic, while Python handled the narrow ML task. The result — the system withstands 10,000 concurrent sessions.

Results Today

FlowBiz now employs 120 people, and annual revenue exceeds 300 million rubles. The team plans to adopt .NET 8 and Blazor for a next-generation web interface. "C# gave us confidence at the start and flexibility for growth," says CEO Sergey. "If we had chosen a more exotic language, the story might have turned out differently."

This case is an excellent example of how a mature technology helps a startup not only survive but also take a leading position in its niche. And for those learning to program, C# remains a reliable choice for building a career in enterprise development.