the front line
noun [ S ]
ukus(also frontline)the place or the area of activity where important, interesting, or difficult things are happening:
on the front line of sth This rural Brazilian city is making a name for itself as being on the front line of the wireless revolution.
be in the front line Accountants are in the front line in the fight against criminal financing.
WORKPLACE
the part of a business that deals directly with customers and the public, or that makes a product:
Hourly, low-wage workers are now on the front line of commerce interacting with the public.