Do you still have a sticker on your rear derailleur? Do you have a warning sticker on the front of your Di2 telling you not to put your finger in there? If you do, you might need to ask yourself if your mechanic has the attention to detail one would expect of someone building something as beautiful and precise as a bike.
A bike comes in a box, which has been partially built by a wonderfully bored factory worker in Taiwan or China. The bike is freighted by sea to your country, lifted and moved many times by bored and angry dock workers, in between union meetings, then put through a number of vehicle and forklift movements making its way finally to your local bike store. As you can tell, there are a number of opportunities for your new bike to be bumped or damaged.
From your store, you need to ensure your bike is fully un-boxed, and very importantly FULLY stripped, checked-over, re-built and test ridden with a Quality Assurance procedure in place to ensure your bike is operating exactly as it should be. If your bike has stickers on parts still, although it might sound like a small and petty thing, it shows that the builder of your bike does not have an attention to detail that is needed when the separation between you staying black-side-down and lots of skin loss from a failed bike at 70km/hr on your favourite descend is our bikes build quality and half an inch of tyre.
You need the right people building your bike, and giving you maintenance throughout your cycling career.