Make sure you ask if your job is part of the core business

After announcing the layoff of about 125 people, the spokesman of eBay explained that the decision is due to the reorganisation of the company to focus on their core business. What is the core of an online auction platform? the marketing? the web development? the network infrastructure? the security or the testing? Next time when you are sitting in a job interview, it's better to make sure you will be hired into the core business.