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Microservices patterns

Service boundaries, discovery, inter-service calls, and decomposition patterns.

6 matches

CQRS with Separate Read and Write Repositories in Python

Implement CQRS in Python with separate write and read repositories, using commands for mutations and frozen DTOs for queries.

cqrs repositories microservices

Python

from dataclasses import dataclass
from typing import Dict, List, Optional


# --- Write side: commands mutate state ---
@dataclass
class CreateUserCommand:
    id: int
    name: str


class UserWriteRepository:
    def __init__(self) -> None:
        self._store: Dict[int, Dict[str, object]] = {}

    def create(self,…

14 0 Open

Microservices patterns medium

Consumer Driven Contract Pact Mock in Python

Define and verify consumer-driven contracts using Pact's Consumer and Provider classes, mocking the provider to assert expected interactions.

pact contract testing microservices

Python

from pact import Consumer, Provider

pact = Consumer('OrderService').has_pact_with(Provider('InventoryService'))

@Pact.verify()
class TestInventoryContract:
    def test_get_inventory(self):
        expected = {"item": "widget", "quantity": 100}
        (pact
         .given('inventory exists for widget')
         .u…

16 0 Open

Microservices patterns easy

How to Implement a Data Helper for Microservices in Python

Create a reusable helper class to serialize, deserialize, and wrap data for microservice communication using dataclasses and JSON.

microservices json dataclass

Python

import json
from dataclasses import dataclass, asdict
from typing import Any, Dict, List


@dataclass
class ServiceResponse:
    status: str
    data: Any
    message: str = ""


class DataHelper:
    """Simple helper for microservice data handling."""

    @staticmethod
    def serialize(data: Dict[str, Any]) -> str:…

13 0 Open

Microservices patterns medium

How to Mock a Choreography Saga in Python

Simulate a choreography-based saga with event envelopes, status tracking, and compensating actions to model distributed transactions.

saga microservices events

Python

import json
from dataclasses import dataclass, asdict
from typing import List, Optional
from enum import Enum


class SagaStatus(Enum):
    PENDING = "PENDING"
    COMPLETING = "COMPLETING"
    COMPLETED = "COMPLETED"
    FAILED = "FAILED"


@dataclass
class EventEnvelope:
    event_type: str
    order_id: str
    sta…

13 0 Open

Microservices patterns easy

How to Mock a GraphQL Backend in Python

Create an in-memory GraphQL mock backend using dataclasses and resolver methods returning plain dictionaries.

graphql mock dataclasses

Python

from dataclasses import dataclass, asdict
from typing import Any, Dict, List


@dataclass
class Product:
    id: int
    name: str
    price: float


@dataclass
class User:
    id: int
    username: str


class MockGraphQLBackend:
    def __init__(self) -> None:
        self.products = [
            Product(id=1, name…

15 0 Open

Microservices patterns medium

How to implement the Database per service pattern in Python

Simulate separate databases per microservice in Python using dataclasses and in-memory dictionaries, showing how services own their data independently.

microservices database-per-service dataclasses

Python

import json
from dataclasses import dataclass, asdict
from typing import Dict, List


@dataclass
class User:
    id: int
    name: str
    email: str


@dataclass
class Order:
    id: int
    user_id: int
    product: str
    amount: float


class UserServiceDB:
    """Simulates a separate database for the User servic…

12 0 Open

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