Ask HN: If you had to develop happytables, which technologies will you use?

happytables.com uses ThemeForce(https://github.com/themeforce/framework), an open source wordpress based framework to power its restaurant website service.

If you are asked to develop a SAAS application similar to happytables which language/framework/technologies you will choose? Why?

Here are some features you may need to implement :

1) Account Management & Billing System

2) Admin Backend : Where customers can login and update their website information. It should be available as both web & mobile app.

3) Front-End should be made available as installable themes (similar to wordpress themes). Third party developers should be able to develop a custom theme using HTML,CSS,javascript, etc.

4) REST API