Your app can be running without actually being healthy.
That sounds strange, but it's a common production problem.
A server can show that a container is running while the application inside it is stuck, unable to connect to its database, or no longer responding to requests.
That's where health checks become important.
What Is a Health Check?
A health check is a simple test that asks your application:
“Are you actually working?”
For a web application, this could be as simple as an endpoint like:
GET /health
The application might return:
{ "status": "ok" }
If the endpoint responds correctly, the platform knows the application is healthy.
If it stops responding, something may have gone wrong.
Why Checking Whether a Container Is Running Isn't Enough
Imagine your Node.js application is running inside a container.
The container itself is technically alive.
But your application could still be:
Stuck during startup Unable to connect to the database Consuming too much memory Returning errors Not accepting HTTP requests
A basic process check might still say everything is fine.
A proper health check looks at the application itself.
Health Checks Help With Deployments
Health checks are especially useful when you're deploying a new version.
You don't want production traffic going to a container that hasn't finished starting correctly.
A safer deployment process is:
Build the new version Start the new container Run health checks Confirm the application is responding Send traffic to the new version Remove the old version
Hostwares uses this type of approach with its deployment system. A new container is started and checked before traffic is switched over. If the health check fails, the old container can continue serving traffic instead of immediately replacing a working version.
What Should a Health Check Test?
It doesn't always need to be complicated.
For many applications, a basic HTTP check is enough.
For example:
GET /health
But for more important applications, you may want the check to verify critical dependencies too.
For example:
Is the application responding? Can it reach the database? Are required services available? Is the application ready to accept traffic?
There is an important distinction here.
Liveness vs Readiness
A liveness check asks:
Is the application process alive?
A readiness check asks:
Is the application ready to receive real traffic?
Keeping these concepts separate can make production systems much easier to manage.
Don't Make Health Checks Too Complicated
There's also a common mistake: putting too much logic into a health endpoint.
Your health check should be fast.
If /health performs ten expensive database queries and calls multiple external APIs, the health check itself can become a problem.
For many applications, a lightweight endpoint is enough.
For example:
GET /health → 200 OK
Then you can use deeper monitoring separately for database connectivity, third-party APIs, queues, and other dependencies.
What Happens When a Health Check Fails?
That depends on your infrastructure.
A platform might:
Restart the container Stop sending traffic to it Mark the deployment as failed Keep the previous version running Alert the development team
The important part is that the system can detect the problem automatically instead of waiting for a user to report that the website is down.
This Matters Even More for Small Teams
Large engineering teams can have people watching infrastructure around the clock.
Small teams usually don't.
If you're running a SaaS, portfolio application, API, internal tool, or AI-generated application with a small team, automated health checks can provide an extra layer of protection.
You don't need a huge DevOps setup just to know whether your application is responding.
Production Is More Than “The App Is Running”
A successful deployment isn't just:
Container = Running
It's closer to:
Container + Application + Dependencies + Traffic = Healthy
That's why health checks are such a small feature with such a big impact.
When you're deploying an application, don't only ask:
“Did the deployment finish?”
Also ask:
“Is the new version actually healthy?”
That small difference can prevent a lot of production headaches.
Deploy With Infrastructure That Checks the Important Things
Hostwares includes health checks as part of its deployment workflow, alongside automatic deployments, application monitoring, and zero-downtime deployment behavior.
So whether you're deploying a Next.js application, API, Docker container, or another production service, health checks should be part of the deployment strategy—not something you think about after the first outage.
Build the app. Deploy it. Make sure it's actually healthy.