I have a programming background, though I did minor programming and focused more on business analysis and project management. I am now in a non-technology strategy role and it has been years since I last programmed or kept up with changing technology. I am looking to build a social media app (will outsource development to a full stack development outfit) and I will like to use an appropriate database(s) and programming languages from the get go that could support scaling the platform up - on the off chance the app is successful and has hundreds of millions of active users years down the road.
Can anyone recommend appropriate databases, backend and frontend programming languages to consider, to ensure a responsive and scalable platform? My concern is the amount of data that would need to be stored (for people's timelines, etc) and because people could potentially create a huge amount of data from their posts and comments. I would appreciate any recommendations or suggestions. Thanks!