While there's certainly something that rings a warning bell here, let me present a counter-opinion: The biggest strides in my career have been the ones where I had to stretch the farthest. It always felt scary as hell, but with a bit of "fake it until you make it", these phases served me as massive boosters for learning, career and personal development. I didn't have too many indications to read if the culture over there is okay, but if it isn't shitty and you manage to get some support and allies higher up, filling the position properly and saving that company's ass might pay off very well for you despite the stress involved. YMMV.