I'm not telling which one to pick, instead of that i will give idea about both of this. You can take your decision.

Option 1

Pros:

1. Front-End and Back-End are different, So you can easily handle many request(Load Balancing).
2. Data Security is more in this, because User cannot change the Data models easily(Data Security).

Cons:

1. You need two different server to host.(More Costing)
2. Changes needs to be done by two places and Deployment.(Extra time)

Option 2

Pros:

1. Cons of Option 1

Cons:

1. Pros of Option 1

It's depend upon your use case, if you're building some static site with small contact us form data to be saved in DB, You can use Option 2. If you're going to create a site which will have fully dynamic data then go for Option 1. Think and take a decision.

Let me know if this works

I'm not telling which one to pick, instead of that i will give idea about both of this. You can take your decision.

Option 1

Pros:

1. Front-End and Back-End are different, so you can easily handle many requests (Load Balancing).
2. Data Security is more in this, because the user cannot change the Data models easily  (Data Security).

Cons:

1. You need two different server to host.  (Higher cost)
2. Changes and deployment needs to be done in two places.  (Extra time)

Option 2

Pros:

1. Cons of Option 1

Cons:

1. Pros of Option 1

It depends upon your use case. If you're building some static site with small "Contact us" form data to be saved in DB, you can use Option 2. If you're going to create a site which will have fully dynamic data then go for Option 1. Think and make a decision.