If you have brickwork then you will probably need to have some of the joints fixed at some point.
I’ve visited sites where repairs made by other masons have proved to be a thin layer of cement spread across cracked or damaged joints. It’s a fast, easy fix, and should be avoided.
For lasting results the joint should be chiseled or ground out sufficiently for the new cement to take hold. A long standing rule of thumb is the depth of the chisel job should be at least twice the width of the joint, going back about an inch.
Then the cement dust should be washed out, the surfaces hydrated, and then the new cement installed.
I often break a job into two segments where I prepare the joints one day, and then install the cement on the next, so the homeowner has a chance to see the preparations done fully and completely. And if I’m doing it all on one day, I try to invite them to see prep stage.
I once was doing 11 homes in a row for one of the larger property managers and I showed them how their previous mason had just feathered over cracks, and that these repairs were failing. I offered to dig out all the damaged joints and let them see, before filling them in. They appreciated it, and a team of their trade supervisors was brought in to consider this new business practice. I won years of repeat business from them.