Many people were surprised to learn on the 20th that Signal uses Amazon/AWS infrastructure. Signal’s president, Meredith Whittaker, had to explain why:
Instant messaging demands near-zero latency. Voice and video in particular require complex global signaling & regional relays to manage jitter and packet loss. These are things that AWS, Azure, and GCP provide at global scale that, practically speaking, others (in the western context) don’t.
It’s important to note that Signal uses end‑to‑end encryption, which means nobody at AWS can access the content.
(By the way: the “reply guys” issue on Mastodon shows up in almost every technical post Meredith makes.)