I'm looking into ways to automate form submissions into a 3rd party web application on a nightly basis. Our client is currently doing all of this manually and it is extremely time consuming and prone to data entry errors.

This 3rd party web application is a legacy system with no direct database access or API. The only way we can submit data is via the web interface so I'm looking into automating this process.

I will have the credentials for logging into the web application so access shouldn't be an issue, however I'm wondering what is the easiest way to accomplish this based on others experience.

The basic requirements are login to the application, click a few links, populate form data, and then click submit.

I've done this with headless browsers like PhantomJS but I'm looking for a solution that can be written in C#. Is Selenium a good tool for this kind of automation or should I look into something else? Thanks!