Found articles claiming that SMS might be available even when Cellular service and wifi is down. Also some gps works as well.
What it does
Use SMS to talk to central server where heavy tasks are handled including web search.
How we built it
Go to handle SMS using Twillio, and python scripts are only responsible for scraping and paging.
Challenges we ran into
Redis was not a good choice. We tried to generalize in the beginning which lead to complexity and it slowed down the development.
Accomplishments that we're proud of
Made generic structure that it is easy to add more programs by tweaking parameters. Made an instant app which shows how SMS can pretend as if it is HTTP.
What we learned
Premature optimization is very bad. Communication is difficult.
What's next for h4h-sms
Add geo points associated with users so that we can let isolated people join another group of people. Complete contacts uploading feature so that we can check safety of people you care about. Rewrite everything in Elixir with PostgreSQL which should be well suited for the task.