In Germany, it is possible to ''make a deposit'' with the bank, so the landlord gets only the confirmation (Bürgschaft). Furthermore, it is also a thing to pay that deposit in rates (installments), not to burden the new tennant immediatelly.
I think it works a lot like insurance: you pay a smidge every month, but you also get no money back at the end, so... not really a deposit. However, it does satisfy the landlord and the deposit is legally provided, so... to give up one or two coffee's every month (for a couple of years) is worth it at the rough beginnings.
For comparisson, you pay some 20 € monthly instead of 3500 € on hands of the landlord. You are moving, you are already burdened with the costs and expenses, so instead of having a financial blow on top of all the misery, you simply walk into the bank, make ''Bürgschaft'' (depost confirmation), agree to pay 20 € monthly, beginning from next month... and you exhale. It is a practical guarantee that the bank wil cover your deposit.
You give that ''Bürgschaft'' (deposit confirmation) to your landlord and all is good. If your landlord later, turns out to be an a..hole, he has to claim the deposit with the bank. If you contest landlords claims (bank will 100% contact you in that case), then it is a direct war between him/her and the bank... and good luck with that. To you it is all the same anyway, as you pay (paid) monthly installment (rate).
If there are no disputes and you are moving out earlier, then you can simply cancel the ''Bürgschaft'' contract (based on canceled rent agreement) and you don't have to pay anymore.
The downside is - no money back.
It is not really a hype thing here, but I've done it and it worked OK; (no disputes though).
Have you visited ''Ukraine'' on lemmy? No need to go to reddit.