Before the work was done, either the foundation repair company or the engineer that told them what to do should have explained to you that this was very likely going to happen. This is very normal because they had to jack the house up, put some piers in and now there will be cracks where there weren't before.
After the work was done, they would have done a plumbing test, and the engineer was to come back and check if the work was done according to his specifications.
It has been my experience that you will continue to see cracks, usually hairline, for the following 2 seasons until the house settles again in the new position.
You can fill the cracks and paint now but they will likely reappear within a few months, until the house settles for about 6 months.
I am not a structural engineer nor a home inspector so the advice here is simply practical.