Am I able to begin work before my eAT (electronic residence permit) has arrived?

I have applied for a Working Holiday visa (my home county is New Zealand) and my understanding is that it has been approved (I began the process over a week ago, have had 2 meetings now - fingerprints taken, paid, docs all signed etc). All the documents state that the Visa is valid from today (10th July) for 12 months but I have to wait for the eAT to be 'processed' which can take 3-6 weeks from what was told, and have read online. One site I read suggested that you are given a temporary permit but I haven't got anything except a reciept for the fees, and I can't find anything to confirm if there is any truth in that suggestion.

I have a few interviews coming up over the next week and I know they will all ask "When can I start?". From the documents I read before applying, I was under the impression that the Visa would take only 3-4 days to process (these were from the German Embassy website) so I put the 14th of July as a start date on applications but I now think the documents were severely outdated.

My main concerned that I will be less attractive to employers as I would only have 11 months left on my initial visa if I have to physically have it before beginning work.

You dont have to wait for eAT to arrive. Most foreigners have started working from day one and got the eAT after 2-3 months.