The backstory: I am a paid intern who did OK initially, and so was handed a fairly major project and was given free reign over it. The project is now over half way done. The client thus far has been very happy and has shown enthusiasm when looking at it. However, they have asked me to add a critical feature which cannot be done without very advanced and computationally expensive techniques. It involves analysing, parsing and adding data from a massive, 30+-year-old dataset without uniform columns and without a uniform schema. This goes way above my pay grade, level of interest and ability. It would probably require machine learning.
At the same time, I am also carrying out several other difficult projects for this company, which are taking up a lot of time.
If I quit, it would be disastrous for the client and would probably lose my current company a lot of credibility, and I now regret starting in the first place. However, it would be the biggest weight off my shoulders.
What are my options here? I like the people I work with. It is a small company and so I would feel bad on a personal level if I quit at this time.
Communication seems to be largely between the client and management, and typically I'm only informed of what the client wants after management has already told them I can do it. Basically, I had no input in deciding whether it was possible, and wasn't actually shown the dataset until after the firm had said they could do it.