Performance optimization: indexes have been added to the database and orjson has been implemented to accelerate API, logs and middleware

app/core/logging.py

@@ -2,6 +2,7 @@
 import sys
 from typing import Any
 
+import orjson
 import structlog
 
 from app.core.config import settings
@@ -18,7 +19,7 @@ def setup_logging() -> None:
         processors.append(structlog.dev.ConsoleRenderer())
     else:
         processors.append(structlog.processors.dict_tracebacks)
-        processors.append(structlog.processors.JSONRenderer())
+        processors.append(structlog.processors.JSONRenderer(serializer=orjson.dumps))
     structlog.configure(
         processors=processors, logger_factory=structlog.stdlib.LoggerFactory()
     )

app/main.py

@@ -3,6 +3,7 @@
 
 import structlog
 from fastapi import FastAPI
+from fastapi.responses import ORJSONResponse
 from prometheus_fastapi_instrumentator import Instrumentator
 from redis.asyncio import Redis
 
@@ -39,6 +40,7 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
     description='FairDrop API HL B2B Dropshipping Platform',
     version='0.1.0',
     lifespan=lifespan,
+    default_response_class=ORJSONResponse,
 )
 
 Instrumentator().instrument(app).expose(app)

app/services/inventory/models.py

@@ -43,17 +43,21 @@ class Reservation(Base):
 
     id: Mapped[UUID] = mapped_column(primary_key=True, default=uuid4)
     qty_reserved: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
-    user_id: Mapped[UUID] = mapped_column(ForeignKey('users.id'), nullable=False)
-    product_id: Mapped[UUID] = mapped_column(ForeignKey('products.id'), nullable=False)
+    user_id: Mapped[UUID] = mapped_column(
+        ForeignKey('users.id'), nullable=False, index=True
+    )
+    product_id: Mapped[UUID] = mapped_column(
+        ForeignKey('products.id'), nullable=False, index=True
+    )
     status: Mapped[str] = mapped_column(
         String(), nullable=False, default='pending', index=True
     )
     idempotency_key: Mapped[str] = mapped_column(String(), nullable=False, unique=True)
     order_id: Mapped[UUID | None] = mapped_column(
-        ForeignKey('orders.id'), nullable=True
+        ForeignKey('orders.id'), nullable=True, index=True
     )
     expires_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), nullable=False
+        DateTime(timezone=True), nullable=False, index=True
     )
     created_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), server_default=func.now(), index=True

app/services/orders/models.py

@@ -28,9 +28,11 @@ class Order(Base):
     __tablename__ = 'orders'
 
     id: Mapped[UUID] = mapped_column(primary_key=True, default=uuid4)
-    user_id: Mapped[UUID] = mapped_column(ForeignKey('users.id'), nullable=False)
+    user_id: Mapped[UUID] = mapped_column(
+        ForeignKey('users.id'), nullable=False, index=True
+    )
     status: Mapped[OrderStatus] = mapped_column(
-        Enum(OrderStatus), nullable=False, default=OrderStatus.PENDING
+        Enum(OrderStatus), nullable=False, default=OrderStatus.PENDING, index=True
     )
     total_amount: Mapped[Decimal] = mapped_column(
         Numeric(DECIMAL_PRECISION, DECIMAL_SCALE), nullable=False
@@ -54,8 +56,12 @@ class OrderItem(Base):
     __tablename__ = 'order_items'
 
     id: Mapped[UUID] = mapped_column(primary_key=True, default=uuid4)
-    order_id: Mapped[UUID] = mapped_column(ForeignKey('orders.id'), nullable=False)
-    product_id: Mapped[UUID] = mapped_column(ForeignKey('products.id'), nullable=False)
+    order_id: Mapped[UUID] = mapped_column(
+        ForeignKey('orders.id'), nullable=False, index=True
+    )
+    product_id: Mapped[UUID] = mapped_column(
+        ForeignKey('products.id'), nullable=False, index=True
+    )
 
     order: Mapped['Order'] = relationship('Order', back_populates='items')
     product_name: Mapped[str] = mapped_column(String(), nullable=False)

app/shared/decorators.py

@@ -1,11 +1,10 @@
-import json
 from collections.abc import Callable
 from functools import wraps
 from typing import Any
 
+import orjson
 from fastapi import HTTPException, Request, Response, status
 from fastapi.encoders import jsonable_encoder
-from fastapi.responses import JSONResponse
 from pydantic import BaseModel
 
 from app.core.config import settings
@@ -39,14 +38,18 @@ async def wrapper(*args: Any, **kwargs: Any) -> Response | Any:
             redis_key = f'idempotency:{idempotency_key}'
             cached_response = await redis_client.get(redis_key)
             if cached_response:
-                data = json.loads(cached_response)
-                return JSONResponse(content=data, status_code=status.HTTP_200_OK)
+                data = orjson.loads(cached_response)
+                return Response(
+                    content=orjson.dumps(data),
+                    status_code=status.HTTP_200_OK,
+                    media_type='application/json',
+                )
             response = await func(*args, **kwargs)
             if isinstance(response, BaseModel):
                 json_str_to_cache = response.model_dump_json()
             else:
                 json_data = jsonable_encoder(response)
-                json_str_to_cache = json.dumps(json_data)
+                json_str_to_cache = orjson.dumps(json_data).decode()
             await redis_client.setex(redis_key, ttl_seconds, json_str_to_cache)
             return response
 

migrations/versions/2a03cc82fdc7_add_performance_indexes.py

@@ -0,0 +1,29 @@
+"""Add performance indexes
+
+Revision ID: 2a03cc82fdc7
+Revises: cdede027cf9b
+Create Date: 2026-03-12 15:35:23.227561
+
+"""
+
+from collections.abc import Sequence
+
+# revision identifiers, used by Alembic.
+revision: str = '2a03cc82fdc7'
+down_revision: str | Sequence[str] | None = 'cdede027cf9b'
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    pass
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    pass
+    # ### end Alembic commands ###

migrations/versions/cdede027cf9b_add_performance_indexes.py

@@ -0,0 +1,57 @@
+"""Add performance indexes
+
+Revision ID: cdede027cf9b
+Revises: da065d87e52a
+Create Date: 2026-03-12 15:35:08.784099
+
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = 'cdede027cf9b'
+down_revision: str | Sequence[str] | None = 'da065d87e52a'
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_index(
+        op.f('ix_order_items_order_id'), 'order_items', ['order_id'], unique=False
+    )
+    op.create_index(
+        op.f('ix_order_items_product_id'), 'order_items', ['product_id'], unique=False
+    )
+    op.create_index(op.f('ix_orders_status'), 'orders', ['status'], unique=False)
+    op.create_index(op.f('ix_orders_user_id'), 'orders', ['user_id'], unique=False)
+    op.create_index(
+        op.f('ix_reservations_expires_at'), 'reservations', ['expires_at'], unique=False
+    )
+    op.create_index(
+        op.f('ix_reservations_order_id'), 'reservations', ['order_id'], unique=False
+    )
+    op.create_index(
+        op.f('ix_reservations_product_id'), 'reservations', ['product_id'], unique=False
+    )
+    op.create_index(
+        op.f('ix_reservations_user_id'), 'reservations', ['user_id'], unique=False
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_reservations_user_id'), table_name='reservations')
+    op.drop_index(op.f('ix_reservations_product_id'), table_name='reservations')
+    op.drop_index(op.f('ix_reservations_order_id'), table_name='reservations')
+    op.drop_index(op.f('ix_reservations_expires_at'), table_name='reservations')
+    op.drop_index(op.f('ix_orders_user_id'), table_name='orders')
+    op.drop_index(op.f('ix_orders_status'), table_name='orders')
+    op.drop_index(op.f('ix_order_items_product_id'), table_name='order_items')
+    op.drop_index(op.f('ix_order_items_order_id'), table_name='order_items')
+    # ### end Alembic commands ###

pyproject.toml

@@ -13,6 +13,7 @@ dependencies = [
     'boto3-stubs[essential,s3]>=1.42.54',
     'email-validator>=2.3.0',
     'fastapi>=0.129.0',
+    'orjson>=3.11.7',
     'passlib[bcrypt]==1.7.4',
     'prometheus-fastapi-instrumentator>=7.1.0',
     'pydantic-settings>=2.12.0',