Add backend directory

backend/main.py

@@ -0,0 +1,8 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/")
+def read_root():
+    return {"message": "Hello, World!"}

backend/tests/test_main.py

@@ -0,0 +1,11 @@
+from fastapi.testclient import TestClient
+
+from main import app
+
+client = TestClient(app)
+
+
+def test_read_root():
+    response = client.get("/")
+    assert response.status_code == 200
+    assert response.json() == {"message": "Hello, World!"}