If you're a solo developer or indie hacker looking for a straightforward way to deploy your app without dealing with infrastructure complexities, Railway is your best option. Its Git-push integration allows you to get your application up and running quickly, making it perfect for rapid development and testing without needing extensive operations knowledge. However, be mindful that it lacks a permanent free tier, and costs can increase with always-on services.
On the other hand, if your application is latency-sensitive and you need to serve users from multiple regions effectively, Fly.io is the way to go. Its true multi-region deployment provides low latency, and its scale-to-zero feature keeps costs down during idle times. Just note that you'll need some operational expertise, and the usage-based billing model may be harder to predict, making it less ideal for those who prefer flat-rate billing or minimal hands-on management.