Translation of “Did it go well?”

Question

Did it go well?

I think we can use the verb passer here, but I'm not sure whether it should be in the reflexive form or not.

C'est bien passé?

or

Ça s'est bien passé?

The verb passer means to pass, while se passer means to happen, so both could conceivably fit here.

Answer 1

C'est bien passé ?
I'm not feeling very well and I'm not feeling hungry, nevertheless my mum wanted me to get some food down my system (mums will be mums...) but afterwards she's worried whether it went down well and she asks: C'est bien passé?

Ça s'est bien passé ?
I've just taken my driving test and the first thing my mum asks is:Ça s'est bien passé ?

So the answer to your question is "no", both are not interchangeable.
Passer (16. Être facile à manger, à digérer). Se passer (Arriver ; avoir lieu.)