diff --git a/README.md b/README.md
index 8229bb8..57fbd3a 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1571 TILs and counting..._
+_1572 TILs and counting..._
 
 See some of the other learning resources I work on:
 - [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
@@ -206,6 +206,7 @@ See some of the other learning resources I work on:
 - [Reload The nginx Configuration](devops/reload-the-nginx-configuration.md)
 - [Resolve The Public IP Of A URL](devops/resolve-the-public-ip-of-a-url.md)
 - [Running Out Of inode Space](devops/running-out-of-inode-space.md)
+- [Set Up Domain For Hatchbox Rails App](devops/set-up-domain-for-hatchbox-rails-app.md)
 - [SSH Into A Docker Container](devops/ssh-into-a-docker-container.md)
 - [SSL Certificates Can Cover Multiple Domains](devops/ssl-certificates-can-cover-multiple-domains.md)
 - [Wipe A Heroku Postgres Database](devops/wipe-a-heroku-postgres-database.md)
diff --git a/devops/set-up-domain-for-hatchbox-rails-app.md b/devops/set-up-domain-for-hatchbox-rails-app.md
new file mode 100644
index 0000000..d50949a
--- /dev/null
+++ b/devops/set-up-domain-for-hatchbox-rails-app.md
@@ -0,0 +1,24 @@
+# Set Up Domain For Hatchbox Rails App
+
+When we deploy a Rails app with [Hatchbox](https://hatchbox.io), we are given
+an internal URL for publicly accessing our app. It is something like
+`https://123abc.hatchboxapp.com`. That's useful as we are getting things up and
+running, but eventually we want to point our own domain at the app.
+
+The first step is to tell Hatchbox what domain we are going to use.
+
+From our app's _Domain & SSL_ page we can enter a domain into the _Add A
+Domain_ input. For instance, I have the
+[visualmode.dev](https://visualmode.dev) domain and I want the
+[still.visualmode.dev](https://still.visualmode.dev) subdomain pointing at my
+Rails app. I submit the full name `still.visualmode.dev` and I get an _A
+Record_ ipv4 address (e.g. `23.12.234.82`).
+
+The second step is to configure a DNS record with our domain registrar.
+
+From the DNS settings of our registrar (e.g. Cloudflare) we can add an _A
+Record_ where we specify the name (e.g. `still`) and then include the ipv4
+address provided by Hatchbox. We can save this and wait a minute for it to
+propagate.
+
+And soon enough we can visit our Rails app at the custom domain.