Hello everybody ! My question is simple, I am willing to use Firebase to make an app. Firebase would be used to store a balance of euros so is it possible for the user to change the values of it ? I mean, without me allowing them to do so.
Is it “hackable” is the question
Hi, I think that this question should be asked on the Firebase forum and ask if this database can be used in the banking system.
To work with confidential data, you need encryption features and a very reliable and stable system operation. Unfortunately, Thunkable X doesn’t have either the first or the second, but you can take a chance.
Everything is hackable.
The real question is will anyone care enough to bother hacking your app?
If the answer is no then you can make it.
If the answer is yes then look elsewhere.
I have been working on Thunkable with. Firebase for a LONG time. I haven’t faced any problems. Firebase is safe plus, it is by Google. Everything by Google is SAFE. now can you please mark this as ‘solved’? 
@rockode Firebase is only as safe as you can make it (i.e. security rules). Sticking a google sticker on a product only makes it look good.