Choosing between Substreams and Subgraphs simply comes down to the task at hand, as both options rely on the exact same underlying data. To give a quick overview, Subgraphs offer a structured historical record that is easily queried via GraphQL. This makes them the perfect solution for applications that interact directly with users. Conversely, Substreams deliver a parallelized stream of data that you can fully customize and shape to your needs. This makes Substreams the optimal choice for handling backfills and powering real-time data pipelines. Ultimately, you just need to select the tool that best fits the specific job you are trying to accomplish.