If there will be a serious load, then it is best to order the development of nativ application. To be developed by competent programmers. Who are able to parallelize threads, so that the load is distributed evenly and the application always runs stably. Read about native app development in this article. Everything is described there in details and what are the advantages of this way of development compared to other variants. I personally prefer nativ development. But it's not always necessary and hybrid development is often used.