Dev here. Just because CPUs don’t directly use 8 bit numbers anymore doesn’t magically mean 257 wouldn’t overflow. If you’re storing the 8 bits in part of something else that’s 32 or 64 bits (or whatever), like maybe the ID of the chat, then you only have 8 bits. A lot of time this comes down to making compact data representations of things to make uploads/downloads quicker. JSON is the most popular data format to transfer data in (probably), but other more compact binary formats like Avro, Protobuf, and even application specific custom formats exist.
Dev here. Just because CPUs don’t directly use 8 bit numbers anymore doesn’t magically mean 257 wouldn’t overflow. If you’re storing the 8 bits in part of something else that’s 32 or 64 bits (or whatever), like maybe the ID of the chat, then you only have 8 bits. A lot of time this comes down to making compact data representations of things to make uploads/downloads quicker. JSON is the most popular data format to transfer data in (probably), but other more compact binary formats like Avro, Protobuf, and even application specific custom formats exist.