PaaS

Platform as a Service sits between raw servers and serverless functions: you push code, and the platform builds it, runs it, connects a database and gives you a URL — but unlike serverless, your app runs as a continuous process. That makes PaaS the natural home for full-stack apps, APIs with persistent connections, background workers and anything built on a framework that expects to stay running.

The defining trade-off on free PaaS tiers is how the provider keeps them affordable. Some idle your app after a period of no traffic and wake it on the next request, trading a cold-start delay for free always-available hosting; others give you a fixed monthly credit that depletes as the app runs. Railway and Render are common picks, and the right one depends on whether your project tolerates sleeping and how its resource usage maps to each platform’s allowance.

When comparing options, check four things: whether the free tier is perpetual or a depleting trial, the sleep/idle policy, what database and persistent storage are included, and the supported runtimes (including Dockerfile support if you need it). A PaaS that bundles a managed Postgres on the same free account saves you from wiring up a separate database provider, which is often the difference between a five-minute deploy and an afternoon of setup.