1/ I spent a bit of time looking at the Canada COVID Alert app this evening. Bottom line: this app is pretty much the model for how to do this kind of tech.

2/ It's super clear about what data it collects and doesn't, and about how it works. This is not easy stuff to convey.

3/ It's such a caring and lovely flow. Here it is letting you know it's about to ask for that single permission it needs – to access the Google/Apple API.

4/ It uses the "one-time key" for declaring yourself positive. You can't just do it willy nilly, you need a health-care provider to confirm you have COVID and then you get to warn others.

(Many hypothesized this tech would be vulnerable to spurious reports... no way.)

5/ And the whole stack is open-source! Client and Server!

https://github.com/cds-snc/covid-alert-app
https://github.com/cds-snc/covid-alert-server

6/ The tech choices are solid.

React Native on the front-end, which is exactly what I would have done. (I would have gone full @expo, but React Native is great.)

Golang, SQL database, Docker on the backend, with a fairly straight-forward API and implementation.

7/ (I would have used JSON instead of protobufs, it would make it a lot easier for other clients, but maybe that doesn't matter so much here.)

8/ So, a carefully designed app that is respectful of users, obviously loops in the health department, uses solid tech stacks that are sufficiently high-level to focus on the key features and not on the low-level generic machinery. All open-source.

Way to go Canada!