diff --git a/backend/problems/admin.py b/backend/problems/admin.py
index 8d9414c9..f072909c 100644
--- a/backend/problems/admin.py
+++ b/backend/problems/admin.py
@@ -103,22 +103,6 @@ def save_model(self, request, obj, form, change):
             obj.author = request.user
         super().save_model(request, obj, form, change)
 
-    # Customize queryset for admin to potentially show more fields or filter
-    # def get_queryset(self, request):
-    #     qs = super().get_queryset(request)
-    #     return qs
-
-
-# TestCase can also be registered separately if needed for direct management,
-# but often managed inline with Problems.
-# class TestCaseAdmin(admin.ModelAdmin):
-#     list_display = ('id', 'problem_id_display', 'order', 'is_sample', 'points')
-#     list_filter = ('problem', 'is_sample')
-#     search_fields = ('problem__title_i18n', 'input_data', 'expected_output_data')
-
-#     def problem_id_display(self, obj):
-#         return obj.problem.id
-#     problem_id_display.short_description = 'Problem ID'
 
 admin.site.register(Tag, TagAdmin)
 admin.site.register(Problem, ProblemAdmin)
diff --git a/backend/users/adapters.py b/backend/users/adapters.py
index a5d8aef9..cec5361d 100644
--- a/backend/users/adapters.py
+++ b/backend/users/adapters.py
@@ -13,7 +13,7 @@ def pre_social_login(self, request, sociallogin):
         # This method is called just before the user is logged in.
         # We can use it to check if the user is new and needs to complete registration.
         if sociallogin.is_existing:
-            return
+            return None
 
         # There is no existing social account for this user.
         # Check if a user already exists with the same email address.
@@ -21,7 +21,7 @@ def pre_social_login(self, request, sociallogin):
             # This will fail if the user does not exist
             _ = sociallogin.user
             # If the user exists, we can just link the social account and log them in.
-            return
+            return None
         except Exception:
             # The user does not exist, so we need to redirect them to complete registration.
             # We'll pass the email address as a query parameter.
@@ -33,4 +33,4 @@ def pre_social_login(self, request, sociallogin):
                 return HttpResponseRedirect(redirect_url)
 
         # If we can't get an email, we'll just let allauth handle it.
-        return
+        return None
diff --git a/backend/users/models.py b/backend/users/models.py
index f4154b66..7ae43cd6 100644
--- a/backend/users/models.py
+++ b/backend/users/models.py
@@ -38,12 +38,3 @@ class Roles(models.TextChoices):
 
     def __str__(self):
         return self.username
-
-    # You might add helper properties here later, e.g.:
-    # @property
-    # def is_problem_creator(self):
-    #     return self.role in {self.Roles.PROBLEM_CREATOR, self.Roles.PROBLEM_VERIFIER, self.Roles.ADMIN}
-
-    # @property
-    # def is_problem_verifier(self):
-    #     return self.role in {self.Roles.PROBLEM_VERIFIER, self.Roles.ADMIN}
diff --git a/backend/users/serializers.py b/backend/users/serializers.py
index 58810807..7c64ed13 100644
--- a/backend/users/serializers.py
+++ b/backend/users/serializers.py
@@ -164,8 +164,4 @@ def save(self, **kwargs):
         user = self.context["request"].user
         user.set_password(self.validated_data["new_password1"])
         user.save()
-        # Optionally, update session auth hash if using session authentication alongside JWT
-        # from django.contrib.auth import update_session_auth_hash
-        # if hasattr(self.context['request'], 'session'):
-        #    update_session_auth_hash(self.context['request'], user)
         return user
diff --git a/backend/webcoder_api/celery.py b/backend/webcoder_api/celery.py
index a758c792..f0e24cdf 100644
--- a/backend/webcoder_api/celery.py
+++ b/backend/webcoder_api/celery.py
@@ -10,7 +10,7 @@
 # ``celery`` ships no type information in the lean type-check environment, so the
 # imported ``Celery`` symbol is opaque (pyright cannot confirm it is callable).
 # Cast it to a callable to construct the app without losing checking elsewhere.
-_Celery = cast("type[Any]", Celery)
+_Celery = cast(type[Any], Celery)
 app = _Celery("webcoder_api")
 
 # Using a string here means the worker doesn't have to serialize
diff --git a/backend/webcoder_api/settings.py b/backend/webcoder_api/settings.py
index fcc541b8..e43fb4e0 100644
--- a/backend/webcoder_api/settings.py
+++ b/backend/webcoder_api/settings.py
@@ -22,7 +22,12 @@
 # See https://docs.djangoproject.com/en/5.2/howto/deployment/checklist/
 
 # SECURITY WARNING: keep the secret key used in production secret!
-SECRET_KEY = "django-insecure-tra1bid*d3-t-+a$uu+1k&l+-aqxrp5u_ezlg5*oa%h$9cg45o"
+# Sourced from the environment; the insecure fallback is for local/dev only and
+# MUST be overridden via DJANGO_SECRET_KEY in any real deployment.
+SECRET_KEY = os.environ.get(
+    "DJANGO_SECRET_KEY",
+    "django-insecure-dev-only-change-me",
+)
 
 # SECURITY WARNING: don't run with debug turned on in production!
 DEBUG = True
@@ -104,11 +109,11 @@
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.postgresql",
-        "NAME": "webcoder_db",  # Replace with your database name
-        "USER": "webcoder_user",  # Replace with your PostgreSQL username
-        "PASSWORD": "darkstarone",  # Replace with your PostgreSQL password
-        "HOST": "localhost",  # Or your PostgreSQL host
-        "PORT": "5432",  # Or your PostgreSQL port
+        "NAME": os.environ.get("POSTGRES_DB", "webcoder_db"),
+        "USER": os.environ.get("POSTGRES_USER", "webcoder_user"),
+        "PASSWORD": os.environ.get("POSTGRES_PASSWORD", ""),
+        "HOST": os.environ.get("POSTGRES_HOST", "localhost"),
+        "PORT": os.environ.get("POSTGRES_PORT", "5432"),
     }
 }
 
@@ -187,9 +192,6 @@
     "email": {"required": True},
     "password1": {"required": True},
 }
-DJ_REST_AUTH = {
-    "SIGNUP_FIELDS": ACCOUNT_SIGNUP_FIELDS,
-}
 SOCIALACCOUNT_PROVIDERS = {
     "google": {
         "SCOPE": [