The speaker talked about string optimization in Go, focusing on the context of the observability landscape and time series databases. They discussed the representation of strings in Go, the overhead of string headers, and the concept of string cloning. They also explored string interning as a technique to store only a single copy of each distinct string and the use of symbol tables. Finally, they mentioned the potential trade-offs between memory savings and retrieval time, and emphasized the importance of data-driven optimization.