I plan on carrying a small suitcase as my hand-luggage on an upcoming economy flight. If possible, I may want to also bring a backpack in addition to the suitcase.
Does Lufthansa actually check how many carry-on bags I am carrying before/while entering the aircraft?
From https://www.lufthansa.com/de/en/carry-on-baggage
Please note that Lufthansa checks during boarding whether the carry-on baggage rules are being adhered to. Carry-on baggage that is too large or too heavy will be taken at the gate and loaded into the cargo hold for a fee. The fees for this are significantly higher at the gate than in the check-in hall and can only be settled by credit card.
In my experience Lufthansa group (including Austrian and Swiss) are more zealous about this than other airlines. In particular they have a 8 kg weight limit that they occasionally enforce. Sometimes they weigh everything thing with wheels or that looks large or heavy.
If possible, I may want to also bring a backpack in addition to the suitcase.
That's fine. You are allowed an additional "small item". There is a size restrictions but I never had an issue with a "normal" sized backpack.
Another small item of baggage (max. x=30 cm y=40 cm z=10 cm, e.g. handbag, laptop bag).
Every flight I have been on I have seen one of the boarding crew look at the carry-on luggage.
In many cases they did not act but in some they do tell people that some of the luggage is too big or that the person has too many items.
How much you can legally take on board may also depend on your ticket.
Besides, on busy flights they sometimes ask to check-in bigger carry-on bags as they expect to run out of space to store them.
