I'm working at
https://dice.fm, we're an entertainment ticketing platform (gigs, festivals, comedy, etc). At it's core we're really just an ecommerce platform but do have to deal with larger events that will sell out extremely quickly.
We've found it tough to hire elixir engineers because there just aren't that many but we're really happy with the tech choice none the less. We're quite a small engineering team and managing to support a global platform and build out new functionality at a really great pace even with our small team. We don't require elixir experience, just an interest or desire to work in it full time. We're forunate that we have a good pool of senior elixir engineers who've been using it for several years so we have a good codebase for people to learn from.
So from our side, we're not working on any "ground breaking new technology", we're just building something rock solid that offers a lot of value to partners and fans vs the competition. For the record we're super happy with our choice of Elixir!
I have seen a bunch of blockchain companies hiring elixir engineers over the past year or so, I suspect quite a few of elixir engineers are working in those startups as well.