How to implement a card or qr code entry system?

Question

Automation

Everything that will be described below, know I'm a NUB in this issue) The
question is more debatable and is aimed at everyone's opinion.
You need to come up with, buy or write a pass system yourself. During the pandemic, the state really wanted to re-digitize its organizations.

What is required from the system?
The IOS / Android mobile application contains all sorts of news, etc., and a QR code scanner, a person comes in and scans the QR code on the wall, then on the server we look to see if it is in the databases, then a two-digit number is shown. He leaves his things in the dressing room under this number. He does his business, after, for example, he wants to take something, for example, a book, and if he is in the databases, then he is assigned to him, if not, then he must be registered.

Any ideas ? What technologies are available for this?
How difficult will it be to implement, etc.?

Answer 1

Hire a specialist, he will do everything for you. And starting with the terms of reference.
In your idea, for example, there is no point in scanning the code on the wall, a person can simply press a button on the site or in the application. However, for this you need to ensure that there is a guest Wi-Fi at the checkpoint.
Moreover, the idea is vulnerable to the fact that the code can be copied from the wall, and then someone Vasily will be able to pass anyone under his account by scanning the code while sitting at home and sending the result.
You can steal the idea from the CPTC - the user buys a ticket, then scans a one-time code from the monitor on the turnstile, "activating" the ticket (since the code changes, this proves that the person is physically standing at a particular turnstile). Then he can present a different code as a ticket for passing through the turnstiles and controllers.
In short, this is a stub of terms of reference, and not a question, not according to the format of the resource, unfortunately. We do not welcome non-specific questions and unleashing discussions and brainstorms.

In order to implement something, you need to clearly set the task for implementation, so that it is clear what problem we are solving.

Answer 2

If this is a system for employees, then it is much easier to take a standard access control system, there is access control, and key holders, and personal lockers, and weight control, and breathalyzers, in general, for every taste.
If this is for visitors, then what will you do with people who do not have a smartphone, a smartphone on an ancient version of android or on windows? Or maybe a person simply does not want to install some kind of left application just to visit your office.