Advanced Sentiment Analysis for Restaurant Reviews

Imagine you are employed by a restaurant review platform similar to Yelp. Your task is to develop a sentiment analysis system that can evaluate restaurant reviews by identifying distinct features and determining the sentiment for each feature. For example, if a review states, "The ambiance was delightful, but the wait time was frustrating!" the system should recognize two features (ambiance and wait time) and their respective sentiments (delightful and frustrating). How would you approach building this sentiment analysis system?