Came in for an onsite, was told to expect front-end specific questions as my background was fully as a front-end developer. I double confirmed with the recruiter and with the coordinator that they would ask front-end specific questions. I got there and they asked fully back-end specific questions, which were all fully out of my experience and I hadn't prepared for based upon what they had communicated to me. I reached out afterwards to let them know nicely about the mishap, and they didn't even be bothered to respond. Things happen, it was a simple mistake or miscommunication along the line, but it wasted a lot of time and effort for both sides. All I really wanted was an acknowledgement, but I guess they couldn't be bothered, and ultimately that really sullied the whole experience.