It is not a question of what technology is best. You can scale anything (im exaggerating a bit). It is more of a question about do you have people on your team

It is not a question of what technology is best. You can scale anything (im exaggerating a bit). It is more of a question about do you have people on your team who know how to scale things? If so, then use the technology that they are most familiar with. If you have not hired anyone yet, then consider this; It is probably easier to find developers with skills in Java, Scala, PHP, Python, or Ruby that know how to scale websites than developers with .NET skills. It is probably easier to find DBA's with MySQL and its derivatives, or PostgreSQL that know how to scale websites than DBA's with MSSQL skills. I could go on, but you get the point. I'm not saying at all that .NET or the Microsoft ecosystem is bad, just that you use what your team knows. And if you don't have a team yet, they will probably know more about a non-Microsoft solution.