diff --git a/apps/submissions/admin.py b/apps/submissions/admin.py
index 19d5b95..49cf45f 100644
--- a/apps/submissions/admin.py
+++ b/apps/submissions/admin.py
@@ -29,4 +29,6 @@ class SubmissionAdmin(SubmissionAdminBase):
     list_display = ("__str__", "author", "task")
     list_filter = ("author", "task", "created_at")
 
-    fieldsets = [(_("Details"), {"fields": ("author", "task", "code")})]
+    fieldsets = [
+        (_("Details"), {"fields": ("author", "task", "code", "status")})
+    ]
diff --git a/apps/submissions/migrations/0003_submission_status.py b/apps/submissions/migrations/0003_submission_status.py
new file mode 100644
index 0000000..323ad92
--- /dev/null
+++ b/apps/submissions/migrations/0003_submission_status.py
@@ -0,0 +1,34 @@
+# Generated by Django 4.2.7 on 2023-11-26 22:26
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("submissions", "0002_alter_submission_code"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="submission",
+            name="status",
+            field=models.TextField(
+                choices=[
+                    ("WJ", "Waiting judge"),
+                    ("JG", "Judging"),
+                    ("AC", "Accepted"),
+                    ("WA", "Wrong answer"),
+                    ("RE", "Runtime error"),
+                    ("TLE", "Time limit exceeded"),
+                    ("MLE", "Memory limit exceeded"),
+                    ("CE", "Compilation error"),
+                    ("IE", "Internal error"),
+                    ("UE", "Unknown error"),
+                    ("SE", "Submission error"),
+                    ("PE", "Presentation error"),
+                ],
+                default="WJ",
+                max_length=3,
+            ),
+        ),
+    ]
diff --git a/apps/submissions/models.py b/apps/submissions/models.py
index 6aa8517..75c4b9a 100644
--- a/apps/submissions/models.py
+++ b/apps/submissions/models.py
@@ -1,11 +1,29 @@
 from django.core.validators import MinLengthValidator
-from django.db.models import CASCADE, ForeignKey, TextField
+from django.db.models import CASCADE, ForeignKey, TextChoices, TextField
+from django.utils.translation import gettext_lazy as _
 
 from apps.tasks.models import Task
 from apps.users.models import User
 from core.models import TimestampedModel
 
 
+class SubmissionStatus(TextChoices):
+    """Represents the status of a submission."""
+
+    WAITING_JUDGE = ("WJ", _("Waiting judge"))
+    JUDGING = ("JG", _("Judging"))
+    ACCEPTED = ("AC", _("Accepted"))
+    WRONG_ANSWER = ("WA", _("Wrong answer"))
+    RUNTIME_ERROR = ("RE", _("Runtime error"))
+    TIME_LIMIT_EXCEEDED = ("TLE", _("Time limit exceeded"))
+    MEMORY_LIMIT_EXCEEDED = ("MLE", _("Memory limit exceeded"))
+    COMPILATION_ERROR = ("CE", _("Compilation error"))
+    INTERNAL_ERROR = ("IE", _("Internal error"))
+    UNKNOWN_ERROR = ("UE", _("Unknown error"))
+    SUBMISSION_ERROR = ("SE", _("Submission error"))
+    PRESENTATION_ERROR = ("PE", _("Presentation error"))
+
+
 class Submission(TimestampedModel):
     """
     Represents a submission to a task by an user. The code field is
@@ -16,6 +34,11 @@ class Submission(TimestampedModel):
     author = ForeignKey(User, related_name="submissions", on_delete=CASCADE)
     task = ForeignKey(Task, related_name="submissions", on_delete=CASCADE)
     code = TextField(validators=[MinLengthValidator(15)])
+    status = TextField(
+        max_length=3,
+        choices=SubmissionStatus.choices,
+        default=SubmissionStatus.WAITING_JUDGE,
+    )
 
     class Meta:
         db_table = "submissions"
diff --git a/apps/submissions/tests.py b/apps/submissions/tests.py
index 4f680f2..fe42958 100644
--- a/apps/submissions/tests.py
+++ b/apps/submissions/tests.py
@@ -90,5 +90,7 @@ def test_list_filter(self) -> None:
         self.assertEqual(self.submission_admin.list_filter, expected)
 
     def test_fieldsets(self) -> None:
-        expected = [(_("Details"), {"fields": ("author", "task", "code")})]
+        expected = [
+            (_("Details"), {"fields": ("author", "task", "code", "status")})
+        ]
         self.assertEqual(self.submission_admin.fieldsets, expected)
diff --git a/apps/tasks/admin.py b/apps/tasks/admin.py
index 7ceebb7..470982d 100644
--- a/apps/tasks/admin.py
+++ b/apps/tasks/admin.py
@@ -1,7 +1,10 @@
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, cast
 
 from django.contrib.admin import ModelAdmin, register
+from django.core.files.uploadedfile import InMemoryUploadedFile
 from django.forms import CharField, IntegerField, ModelForm, Textarea
+from django.forms.fields import FileField
+from django.http import HttpRequest
 from django.utils.translation import gettext_lazy as _
 
 from apps.tasks.models import Task
@@ -19,12 +22,19 @@ class TaskModelForm(TaskModelFormBase):
     score = IntegerField(min_value=0, required=False)
 
     memory_limit = IntegerField(
-        min_value=0, required=False, help_text=_("In bytes.")
+        min_value=0,
+        required=False,
+        help_text=_("In bytes."),
     )
     time_limit = IntegerField(
-        min_value=0, required=False, help_text=_("In seconds.")
+        min_value=0,
+        required=False,
+        help_text=_("In seconds."),
     )
 
+    input_file = FileField()
+    output_file = FileField()
+
     class Meta:
         model = Task
         fields = "__all__"
@@ -41,4 +51,22 @@ class TaskAdmin(TaskAdminBase):
         (_("General"), {"fields": ("title", "description")}),
         (_("Meta"), {"fields": ("contest", "score")}),
         (_("Limits"), {"fields": ("memory_limit", "time_limit")}),
+        (_("Test case"), {"fields": ("input_file", "output_file")}),
     ]
+
+    def save_model(
+        self,
+        request: HttpRequest,
+        obj: Task,
+        form: TaskModelForm,
+        change: bool,
+    ) -> None:
+        # request.FILES does not cast to the correct type so we need to
+        # cast it manually, otherwise Mypy will complain.
+        input_file = cast(InMemoryUploadedFile, request.FILES["input_file"])
+        output_file = cast(InMemoryUploadedFile, request.FILES["output_file"])
+
+        obj.input_file = input_file.read().decode("utf-8")
+        obj.output_file = output_file.read().decode("utf-8")
+
+        return super().save_model(request, obj, form, change)
diff --git a/apps/tasks/migrations/0004_task_input_file_task_output_file.py b/apps/tasks/migrations/0004_task_input_file_task_output_file.py
new file mode 100644
index 0000000..c02435c
--- /dev/null
+++ b/apps/tasks/migrations/0004_task_input_file_task_output_file.py
@@ -0,0 +1,22 @@
+# Generated by Django 4.2.7 on 2023-11-26 21:58
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("tasks", "0003_task_memory_limit_task_score_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="task",
+            name="input_file",
+            field=models.TextField(),
+        ),
+        migrations.AddField(
+            model_name="task",
+            name="output_file",
+            field=models.TextField(),
+        ),
+    ]
diff --git a/apps/tasks/models.py b/apps/tasks/models.py
index 3443d00..c9d4c84 100644
--- a/apps/tasks/models.py
+++ b/apps/tasks/models.py
@@ -1,4 +1,10 @@
-from django.db.models import CASCADE, CharField, ForeignKey, IntegerField
+from django.db.models import (
+    CASCADE,
+    CharField,
+    ForeignKey,
+    IntegerField,
+    TextField,
+)
 
 from apps.contests.enums import ContestStatus
 from apps.contests.models import Contest
@@ -17,6 +23,9 @@ class Task(TimestampedModel):
     memory_limit = IntegerField(null=True)
     time_limit = IntegerField(null=True)
 
+    input_file = TextField()
+    output_file = TextField()
+
     class Meta:
         db_table = "tasks"
 
diff --git a/apps/tasks/tests.py b/apps/tasks/tests.py
index b19c659..37eb078 100644
--- a/apps/tasks/tests.py
+++ b/apps/tasks/tests.py
@@ -1,14 +1,17 @@
 from datetime import timedelta
+from io import BytesIO
 
 from django.contrib.admin.sites import AdminSite
+from django.core.files.uploadedfile import InMemoryUploadedFile
 from django.test import TestCase
+from django.test.client import RequestFactory
 from django.urls import resolve, reverse
 from django.utils import timezone
 
 from apps.contests.models import Contest
 from apps.submissions.forms import SubmissionForm
-from apps.submissions.models import Submission
-from apps.tasks.admin import TaskAdmin
+from apps.submissions.models import Submission, SubmissionStatus
+from apps.tasks.admin import TaskAdmin, TaskModelForm
 from apps.tasks.models import Task
 from apps.tasks.views import DetailView
 from apps.users.models import User
@@ -71,6 +74,7 @@ def test_cancelled_contest_is_not_accessible(self) -> None:
 class TaskAdminTestCase(TestCase):
     def setUp(self) -> None:
         now = timezone.now()
+
         self.site = AdminSite()
         self.admin = TaskAdmin(Task, self.site)
 
@@ -81,7 +85,6 @@ def setUp(self) -> None:
             end_time=now + timedelta(hours=1),
             cancelled=False,
         )
-        self.contest.save()
 
     def test_list_display(self) -> None:
         list_display = self.admin.list_display
@@ -97,14 +100,70 @@ def test_list_filter(self) -> None:
 
     def test_fieldsets(self) -> None:
         fieldsets = self.admin.fieldsets
+
         expected = [
             (("General"), {"fields": ("title", "description")}),
             (("Meta"), {"fields": ("contest", "score")}),
             (("Limits"), {"fields": ("memory_limit", "time_limit")}),
+            ("Test case", {"fields": ("input_file", "output_file")}),
         ]
 
         self.assertEqual(fieldsets, expected)
 
+    def test_save_model(self) -> None:
+        title = "Example task"
+        description = "Some example task"
+        memory_limit = 256
+        time_limit = 1
+
+        input_text = "Hello, World!"
+        output_text = "Hello, World!"
+
+        input_file = InMemoryUploadedFile(
+            file=BytesIO(input_text.encode("utf-8")),
+            field_name="input_file",
+            name="input.txt",
+            content_type="text/plain",
+            size=13,
+            charset="utf-8",
+        )
+        output_file = InMemoryUploadedFile(
+            file=BytesIO(output_text.encode("utf-8")),
+            field_name="output_file",
+            name="output.txt",
+            content_type="text/plain",
+            size=13,
+            charset="utf-8",
+        )
+
+        # We're gonna use RequestFactory to mock a request. This is
+        # necessary because the save_model method requires a request
+        # object with the FILES attribute.
+        mock = RequestFactory()
+        request = mock.post("/admin/tasks/task/add/")
+
+        request.FILES["input_file"] = input_file
+        request.FILES["output_file"] = output_file
+
+        task = Task(
+            title=title,
+            description=description,
+            memory_limit=memory_limit,
+            time_limit=time_limit,
+            contest=self.contest,
+        )
+
+        self.admin.save_model(
+            request=request, obj=task, form=TaskModelForm(), change=False
+        )
+
+        self.assertEqual(task.title, title)
+        self.assertEqual(task.description, description)
+        self.assertEqual(task.memory_limit, memory_limit)
+        self.assertEqual(task.time_limit, time_limit)
+        self.assertEqual(task.input_file, input_text)
+        self.assertEqual(task.output_file, output_text)
+
 
 class TaskURLTestCase(TestCase):
     def test_detail_url_to_view_name(self) -> None:
@@ -122,13 +181,13 @@ def test_detail_url_reverse(self) -> None:
         self.assertEqual(url, expected)
 
 
-class DetailViewTestCase(TestCase):
+class TasksViewTestCase(TestCase):
     def setUp(self) -> None:
         now = timezone.now()
         start_time = now - timedelta(hours=1)
         end_time = now + timedelta(hours=1)
 
-        self.code = "print('Hello World')"
+        self.code = "print('Hello, World!')"
 
         self.contest = Contest._default_manager.create(
             title="Test Contest 1",
@@ -147,19 +206,28 @@ def setUp(self) -> None:
             password="password",
         )
 
+        self.submission = Submission._default_manager.create(
+            author=self.user,
+            task=self.task,
+            code="print('Hello, World!')",
+            status=SubmissionStatus.ACCEPTED,
+        )
+
         self.url = reverse("tasks:detail", args=[self.task.id])
+        self.view = DetailView()
+        self.view.object = self.task
 
     def test_send_submission_successfully(self) -> None:
         self.client.force_login(self.user)
 
         self.client.post(self.url, data={"code": self.code})
-        self.assertEqual(Submission._default_manager.count(), 1)
+        self.assertEqual(Submission._default_manager.count(), 2)
 
     def test_send_submission_with_short_code(self) -> None:
         self.client.force_login(self.user)
 
         self.client.post(self.url, data={"code": "c"})
-        self.assertEqual(Submission._default_manager.count(), 0)
+        self.assertEqual(Submission._default_manager.count(), 1)
 
     def test_detail_view_model_is_task(self) -> None:
         self.assertEqual(DetailView.model, Task)
@@ -171,8 +239,6 @@ def test_detail_view_form_class_is_submission_form(self) -> None:
         self.assertEqual(DetailView.form_class, SubmissionForm)
 
     def test_send_submission_is_redirecting(self) -> None:
-        self.client.force_login(self.user)
-
         response = self.client.post(self.url, data={"code": self.code})
         self.assertEqual(response.status_code, 302)
 
@@ -190,3 +256,41 @@ def test_access_task_that_is_not_accessible(self) -> None:
 
         response = self.client.get(self.url)
         self.assertEqual(response.status_code, 302)
+
+    def test_handle_submission_with_exception(self) -> None:
+        self.client.force_login(self.user)
+
+        code = "raise Exception('Test exception')"
+        expected = "Exception: Test exception"
+
+        response = self.client.post(self.url, data={"code": code})
+
+        self.assertEqual(response.status_code, 200)
+        self.assertInHTML(expected, response.content.decode())
+
+    def test_handle_submission_with_correct_output(self) -> None:
+        self.client.force_login(self.user)
+
+        self.task.output_file = "Hello, World!\n"
+        self.task.save()
+
+        response = self.client.post(self.url, data={"code": self.code})
+        expected = "Correct!"
+
+        self.assertEqual(response.status_code, 200)
+        self.assertHTMLEqual(response.content.decode(), expected)
+
+    def test_handle_submission_with_wrong_output(self) -> None:
+        self.client.force_login(self.user)
+
+        self.task.output_file = "Hello, World!"
+        self.task.save()
+
+        response = self.client.post(self.url, data={"code": self.code})
+        expected = "Incorrect!"
+
+        self.assertEqual(response.status_code, 200)
+        self.assertHTMLEqual(response.content.decode(), expected)
+
+    def test_form_success_url(self) -> None:
+        self.assertEqual(self.view.get_success_url(), self.url)
diff --git a/apps/tasks/views.py b/apps/tasks/views.py
index 9278226..dff5fbe 100644
--- a/apps/tasks/views.py
+++ b/apps/tasks/views.py
@@ -1,3 +1,6 @@
+import sys
+from io import StringIO
+from traceback import format_exc
 from typing import TYPE_CHECKING, Any, Dict
 
 from django.http import HttpRequest, HttpResponse
@@ -18,6 +21,44 @@
     FormMixinBase = FormMixin
 
 
+def handle_submission(request: HttpRequest, task: Task) -> HttpResponse:
+    submission = Submission._default_manager.create(
+        code=request.POST["code"],
+        task=task,
+        author=request.user,
+    )
+
+    input_data = StringIO(task.input_file)
+
+    old_stdin = sys.stdin
+    sys.stdin = input_data
+
+    old_stdout = sys.stdout
+    sys.stdout = stdout = StringIO()
+
+    try:
+        eval(compile(request.POST["code"], "<string>", "exec"))
+    except Exception as exc:
+        submission.status = "RE"
+        submission.save()
+
+        return HttpResponse(f"Error: {exc} {format_exc()}")
+    finally:
+        sys.stdout = old_stdout
+        sys.stdin = old_stdin
+
+    output = stdout.getvalue()
+
+    if output == task.output_file:
+        submission.status = "AC"
+        submission.save()
+        return HttpResponse("Correct!")
+    else:
+        submission.status = "WA"
+        submission.save()
+        return HttpResponse("Incorrect!")
+
+
 class DetailView(FormMixinBase, DetailViewBase):
     model = Task
     template_name = "tasks/detail.html"
@@ -53,13 +94,7 @@ def post(self, request: HttpRequest, *, pk: int) -> HttpResponse:
         self.object = self.get_object()
         form = self.get_form()
 
-        if form.is_valid():
-            Submission._default_manager.create(
-                code=request.POST, task=self.object, author=request.user
-            )
+        if not form.is_valid():
+            return self.form_invalid(form)
 
-        return (
-            self.form_valid(form)
-            if form.is_valid()
-            else self.form_invalid(form)
-        )
+        return handle_submission(request, self.object)
diff --git a/docker-compose.yml b/docker-compose.yml
index 9986807..d321115 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -21,6 +21,8 @@ services:
       - main
     env_file:
       - config/.env
+    depends_on:
+      - postgres
     command: python -Wd manage.py runserver 0.0.0.0:8000
 
   postgres: