1. There are a lot of programmers around the world. There are even global freelance exchanges where you can find not just a contractor who works for himself, but an official company. For your purposes there are a lot of good professionals. And I like your idea. For fitness to make an application.

  2. Beautiful smartphones. But I like the iPhone better.

  3. Almost all large companies use data storage. This of course costs money, because you need your own server and a team of programmers, but without the storage it is impossible to work. Anyone interested can read here https://inoxoft.com/blog/data-warehouse-vs-data-lake-pros-cons-and-what-to-choose-for-business/ about data storage and data lake. There are detailed descriptions of the pros and cons of methods of storing and using information.

  4. Thanks for the link. There are a lot of programmers, but there are even fewer good ones. I will soon be opening my own bookmaker's office and I will need the services of this company. This is a serious project. A lot of financial transactions. Good protection will be needed.