[lancefisher]

We use .NET at Submittable (YC12)! When our founders started the company, it's what they were proficient with from their previous jobs. They opted for building fast with what they knew so they could get a product to market quickly - and it worked.

Our legacy web app uses ASP.NET MVC which is a bit of a pain from a DevOps perspective since it has to run on Windows servers. We also use SQL Server which end up costing 2X what MySQL or PostgreSQL would on RDS. However, our newer code is .NET Core, and we run it on AWS Lambda. We decided to stick with C# since our dev team knows it, and it's a great language. I also really like the direction MS is headed right now with their focus on developers. We have decided to switch to PostgreSQL with our newer services for the cost savings, advanced monitoring, and scaling offered on Aurora. I'd still recommend SQL Server though. It's simple and easy to use in general.

We're a bit of an atypical startup. We are based in Missoula, MT. If you are into .NET, we're hiring - send me an email (it's in my profile).