diff --git a/jupyterhub_config.py b/jupyterhub_config.py
index 2a51eb4..697882c 100644
--- a/jupyterhub_config.py
+++ b/jupyterhub_config.py
@@ -1,23 +1,30 @@
+"""
+jupyterhub_config purely used for testing changes to templates.
+
+See README.md for information on how to test this out.
+"""
 import pathlib
 from oauthenticator.generic import GenericOAuthenticator
 from jupyterhub.spawner import SimpleLocalProcessSpawner
 
 
-c.JupyterHub.spawner_class = SimpleLocalProcessSpawner
-
 HERE = pathlib.Path(__file__).parent
 
+# Add templates from our local checkout to the path JupyterHub searches
+# This allows us to override any template present in upstream
+# jupyterhub (https://github.com/jupyterhub/jupyterhub/tree/main/share/jupyterhub/templates)
+# locally
 c.JupyterHub.template_paths = [str(HERE / 'templates')]
 
+# We use this so we can get a 'login' button, instead of a username / password
+# field.
 c.JupyterHub.authenticator_class = GenericOAuthenticator
 
-c.Authenticator.admin_users = [
-    'yuvipanda'
-]
-
+# Variables that are passed through to templates!
 c.JupyterHub.template_vars = {
     'custom': {
         "interface_selector": True,
+        "default_url": "/rstudio",
         'org': {
             'name': 'University of Foo',
             'logo_url': 'https://jupyter.org/assets/nav_logo.svg',
diff --git a/templates/login.html b/templates/login.html
index 276a234..0512c69 100644
--- a/templates/login.html
+++ b/templates/login.html
@@ -34,13 +34,25 @@
       <div class="form-group interface-selector">
         <label>After logging in, open: </label>
         <label class="radio-inline">
-          <input type="radio" name="interface" value="tree" checked>Jupyter Notebook
+          <input type="radio" name="interface" value="tree"
+                 {% if "default_url" not in custom or custom["default_url"] == "/tree" %}
+                 checked
+                 {% endif %}
+                 >Jupyter Notebook
         </label>
         <label class="radio-inline">
-          <input type="radio" name="interface" value="rstudio">RStudio
+          <input type="radio" name="interface" value="rstudio"
+                 {% if "default_url" in custom and custom["default_url"] == "/rstudio" %}
+                 checked
+                 {% endif %}
+                 >RStudio
         </label>
         <label class="radio-inline">
-          <input type="radio" name="interface" value="lab">JupyterLab
+          <input type="radio" name="interface" value="lab"
+                 {% if "default_url" in custom and custom["default_url"] == "/lab" %}
+                 checked
+                 {% endif %}
+                 >JupyterLab
         </label>
       </div>
     </form>