Slightly off-topic, but here's what I would've done: just build a website. No real client-side code; lean on the HTML platform for everything it can be used fo

Slightly off-topic, but here's what I would've done: just build a website. No real client-side code; lean on the HTML platform for everything it can be used for. HTML is the simplest, most stable, and most battle-tested client-side framework ever created, and it's stateless and runs on all devices without even an installation step. Toss some CSS on there to make it look pretty; CSS is stateless too so it won't introduce any real bugs. It doesn't have to look perfect; you're not marketing it to anyone. You're just collecting input from users who don't have a choice of product. For the back-end use something dead-simple like PHP or NodeJS. The business logic can't be that complicated; I assume it's really a very simple CRUD app. Just accept form submissions, authenticate, validate, drop it in the database. Done. Spin up a couple of hand-managed VMs on DigitalOcean or the like for hosting both the databases (probably just one database?) and the web servers. It's not a small user load, but it's much smaller than the typical internet company, and it only needs to run for a few hours. You don't need automated scaling and restarting while you sleep. Sit a task force at their desks during the event to repair any outages as they happen. Use the right tool for the job. Your stack should be exactly as complicated as the task demands, and no more.