So I started working on a side project using elixir and phoenix last month. In phoenix cookies are set to never expire. Which is a bit of security issue for logins, since someone could get that cookie and pose as that person forever. Not major especially if you use https but still could be easily tighten up.
Anyhow I wanted post where and how to set a max age on your cookies in phoenix, since it took a bit of searching for me to find.