Agent skill

backend-patterns

Node.js, Express ve Next.js API routes için backend mimari kalıpları, API tasarımı, veritabanı optimizasyonu ve sunucu tarafı en iyi uygulamalar.

View SKILL.md on GitHub Repository
Stars 132,726
Forks 19,206

Install this agent skill to your Project

npx add-skill https://github.com/affaan-m/everything-claude-code/tree/main/docs/tr/skills/backend-patterns

SKILL.md

Backend Geliştirme Kalıpları

Ölçeklenebilir sunucu tarafı uygulamalar için backend mimari kalıpları ve en iyi uygulamalar.

Ne Zaman Aktifleştirmelisiniz

  • REST veya GraphQL API endpoint'leri tasarlarken
  • Repository, service veya controller katmanları uygularken
  • Veritabanı sorgularını optimize ederken (N+1, indeksleme, bağlantı havuzu)
  • Önbellekleme eklerken (Redis, in-memory, HTTP cache başlıkları)
  • Arka plan işleri veya async işleme ayarlarken
  • API'ler için hata yönetimi ve doğrulama yapılandırırken
  • Middleware oluştururken (auth, logging, rate limiting)

API Tasarım Kalıpları

RESTful API Yapısı

typescript
// PASS: Kaynak tabanlı URL'ler
GET    /api/markets                 # Kaynakları listele
GET    /api/markets/:id             # Tek kaynak getir
POST   /api/markets                 # Kaynak oluştur
PUT    /api/markets/:id             # Kaynağı değiştir (tam)
PATCH  /api/markets/:id             # Kaynağı güncelle (kısmi)
DELETE /api/markets/:id             # Kaynağı sil

// PASS: Filtreleme, sıralama, sayfalama için query parametreleri
GET /api/markets?status=active&sort=volume&limit=20&offset=0

Repository Kalıbı

typescript
// Veri erişim mantığını soyutla
interface MarketRepository {
  findAll(filters?: MarketFilters): Promise<Market[]>
  findById(id: string): Promise<Market | null>
  create(data: CreateMarketDto): Promise<Market>
  update(id: string, data: UpdateMarketDto): Promise<Market>
  delete(id: string): Promise<void>
}

class SupabaseMarketRepository implements MarketRepository {
  async findAll(filters?: MarketFilters): Promise<Market[]> {
    let query = supabase.from('markets').select('*')

    if (filters?.status) {
      query = query.eq('status', filters.status)
    }

    if (filters?.limit) {
      query = query.limit(filters.limit)
    }

    const { data, error } = await query

    if (error) throw new Error(error.message)
    return data
  }

  // Diğer metodlar...
}

Service Katmanı Kalıbı

typescript
// İş mantığı veri erişiminden ayrılmış
class MarketService {
  constructor(private marketRepo: MarketRepository) {}

  async searchMarkets(query: string, limit: number = 10): Promise<Market[]> {
    // İş mantığı
    const embedding = await generateEmbedding(query)
    const results = await this.vectorSearch(embedding, limit)

    // Tam veriyi getir
    const markets = await this.marketRepo.findByIds(results.map(r => r.id))

    // Benzerliğe göre sırala
    return markets.sort((a, b) => {
      const scoreA = results.find(r => r.id === a.id)?.score || 0
      const scoreB = results.find(r => r.id === b.id)?.score || 0
      return scoreA - scoreB
    })
  }

  private async vectorSearch(embedding: number[], limit: number) {
    // Vector arama implementasyonu
  }
}

Middleware Kalıbı

typescript
// Request/response işleme hattı
export function withAuth(handler: NextApiHandler): NextApiHandler {
  return async (req, res) => {
    const token = req.headers.authorization?.replace('Bearer ', '')

    if (!token) {
      return res.status(401).json({ error: 'Unauthorized' })
    }

    try {
      const user = await verifyToken(token)
      req.user = user
      return handler(req, res)
    } catch (error) {
      return res.status(401).json({ error: 'Invalid token' })
    }
  }
}

// Kullanım
export default withAuth(async (req, res) => {
  // Handler req.user'a erişebilir
})

Veritabanı Kalıpları

Sorgu Optimizasyonu

typescript
// PASS: İYİ: Sadece gerekli sütunları seç
const { data } = await supabase
  .from('markets')
  .select('id, name, status, volume')
  .eq('status', 'active')
  .order('volume', { ascending: false })
  .limit(10)

// FAIL: KÖTÜ: Her şeyi seç
const { data } = await supabase
  .from('markets')
  .select('*')

N+1 Sorgu Önleme

typescript
// FAIL: KÖTÜ: N+1 sorgu problemi
const markets = await getMarkets()
for (const market of markets) {
  market.creator = await getUser(market.creator_id)  // N sorgu
}

// PASS: İYİ: Toplu getirme
const markets = await getMarkets()
const creatorIds = markets.map(m => m.creator_id)
const creators = await getUsers(creatorIds)  // 1 sorgu
const creatorMap = new Map(creators.map(c => [c.id, c]))

markets.forEach(market => {
  market.creator = creatorMap.get(market.creator_id)
})

Transaction Kalıbı

typescript
async function createMarketWithPosition(
  marketData: CreateMarketDto,
  positionData: CreatePositionDto
) {
  // Supabase transaction kullan
  const { data, error } = await supabase.rpc('create_market_with_position', {
    market_data: marketData,
    position_data: positionData
  })

  if (error) throw new Error('Transaction failed')
  return data
}

// Supabase'de SQL fonksiyonu
CREATE OR REPLACE FUNCTION create_market_with_position(
  market_data jsonb,
  position_data jsonb
)
RETURNS jsonb
LANGUAGE plpgsql
AS $$
BEGIN
  -- Transaction otomatik başlar
  INSERT INTO markets VALUES (market_data);
  INSERT INTO positions VALUES (position_data);
  RETURN jsonb_build_object('success', true);
EXCEPTION
  WHEN OTHERS THEN
    -- Rollback otomatik olur
    RETURN jsonb_build_object('success', false, 'error', SQLERRM);
END;
$$;

Önbellekleme Stratejileri

Redis Önbellekleme Katmanı

typescript
class CachedMarketRepository implements MarketRepository {
  constructor(
    private baseRepo: MarketRepository,
    private redis: RedisClient
  ) {}

  async findById(id: string): Promise<Market | null> {
    // Önce önbelleği kontrol et
    const cached = await this.redis.get(`market:${id}`)

    if (cached) {
      return JSON.parse(cached)
    }

    // Cache miss - veritabanından getir
    const market = await this.baseRepo.findById(id)

    if (market) {
      // 5 dakika önbellekle
      await this.redis.setex(`market:${id}`, 300, JSON.stringify(market))
    }

    return market
  }

  async invalidateCache(id: string): Promise<void> {
    await this.redis.del(`market:${id}`)
  }
}

Cache-Aside Kalıbı

typescript
async function getMarketWithCache(id: string): Promise<Market> {
  const cacheKey = `market:${id}`

  // Önbelleği dene
  const cached = await redis.get(cacheKey)
  if (cached) return JSON.parse(cached)

  // Cache miss - DB'den getir
  const market = await db.markets.findUnique({ where: { id } })

  if (!market) throw new Error('Market not found')

  // Önbelleği güncelle
  await redis.setex(cacheKey, 300, JSON.stringify(market))

  return market
}

Hata Yönetimi Kalıpları

Merkezi Hata Yöneticisi

typescript
class ApiError extends Error {
  constructor(
    public statusCode: number,
    public message: string,
    public isOperational = true
  ) {
    super(message)
    Object.setPrototypeOf(this, ApiError.prototype)
  }
}

export function errorHandler(error: unknown, req: Request): Response {
  if (error instanceof ApiError) {
    return NextResponse.json({
      success: false,
      error: error.message
    }, { status: error.statusCode })
  }

  if (error instanceof z.ZodError) {
    return NextResponse.json({
      success: false,
      error: 'Validation failed',
      details: error.errors
    }, { status: 400 })
  }

  // Beklenmeyen hataları logla
  console.error('Unexpected error:', error)

  return NextResponse.json({
    success: false,
    error: 'Internal server error'
  }, { status: 500 })
}

// Kullanım
export async function GET(request: Request) {
  try {
    const data = await fetchData()
    return NextResponse.json({ success: true, data })
  } catch (error) {
    return errorHandler(error, request)
  }
}

Exponential Backoff ile Tekrar Deneme

typescript
async function fetchWithRetry<T>(
  fn: () => Promise<T>,
  maxRetries = 3
): Promise<T> {
  let lastError: Error

  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn()
    } catch (error) {
      lastError = error as Error

      if (i < maxRetries - 1) {
        // Exponential backoff: 1s, 2s, 4s
        const delay = Math.pow(2, i) * 1000
        await new Promise(resolve => setTimeout(resolve, delay))
      }
    }
  }

  throw lastError!
}

// Kullanım
const data = await fetchWithRetry(() => fetchFromAPI())

Kimlik Doğrulama ve Yetkilendirme

JWT Token Doğrulama

typescript
import jwt from 'jsonwebtoken'

interface JWTPayload {
  userId: string
  email: string
  role: 'admin' | 'user'
}

export function verifyToken(token: string): JWTPayload {
  try {
    const payload = jwt.verify(token, process.env.JWT_SECRET!) as JWTPayload
    return payload
  } catch (error) {
    throw new ApiError(401, 'Invalid token')
  }
}

export async function requireAuth(request: Request) {
  const token = request.headers.get('authorization')?.replace('Bearer ', '')

  if (!token) {
    throw new ApiError(401, 'Missing authorization token')
  }

  return verifyToken(token)
}

// API route'unda kullanım
export async function GET(request: Request) {
  const user = await requireAuth(request)

  const data = await getDataForUser(user.userId)

  return NextResponse.json({ success: true, data })
}

Rol Tabanlı Erişim Kontrolü

typescript
type Permission = 'read' | 'write' | 'delete' | 'admin'

interface User {
  id: string
  role: 'admin' | 'moderator' | 'user'
}

const rolePermissions: Record<User['role'], Permission[]> = {
  admin: ['read', 'write', 'delete', 'admin'],
  moderator: ['read', 'write', 'delete'],
  user: ['read', 'write']
}

export function hasPermission(user: User, permission: Permission): boolean {
  return rolePermissions[user.role].includes(permission)
}

export function requirePermission(permission: Permission) {
  return (handler: (request: Request, user: User) => Promise<Response>) => {
    return async (request: Request) => {
      const user = await requireAuth(request)

      if (!hasPermission(user, permission)) {
        throw new ApiError(403, 'Insufficient permissions')
      }

      return handler(request, user)
    }
  }
}

// Kullanım - HOF handler'ı sarar
export const DELETE = requirePermission('delete')(
  async (request: Request, user: User) => {
    // Handler doğrulanmış yetki ile kullanıcı alır
    return new Response('Deleted', { status: 200 })
  }
)

Rate Limiting

Basit In-Memory Rate Limiter

typescript
class RateLimiter {
  private requests = new Map<string, number[]>()

  async checkLimit(
    identifier: string,
    maxRequests: number,
    windowMs: number
  ): Promise<boolean> {
    const now = Date.now()
    const requests = this.requests.get(identifier) || []

    // Pencere dışındaki eski istekleri kaldır
    const recentRequests = requests.filter(time => now - time < windowMs)

    if (recentRequests.length >= maxRequests) {
      return false  // Rate limit aşıldı
    }

    // Mevcut isteği ekle
    recentRequests.push(now)
    this.requests.set(identifier, recentRequests)

    return true
  }
}

const limiter = new RateLimiter()

export async function GET(request: Request) {
  const ip = request.headers.get('x-forwarded-for') || 'unknown'

  const allowed = await limiter.checkLimit(ip, 100, 60000)  // 100 req/dak

  if (!allowed) {
    return NextResponse.json({
      error: 'Rate limit exceeded'
    }, { status: 429 })
  }

  // İstekle devam et
}

Arka Plan İşleri ve Kuyruklar

Basit Kuyruk Kalıbı

typescript
class JobQueue<T> {
  private queue: T[] = []
  private processing = false

  async add(job: T): Promise<void> {
    this.queue.push(job)

    if (!this.processing) {
      this.process()
    }
  }

  private async process(): Promise<void> {
    this.processing = true

    while (this.queue.length > 0) {
      const job = this.queue.shift()!

      try {
        await this.execute(job)
      } catch (error) {
        console.error('Job failed:', error)
      }
    }

    this.processing = false
  }

  private async execute(job: T): Promise<void> {
    // İş yürütme mantığı
  }
}

// Market indeksleme için kullanım
interface IndexJob {
  marketId: string
}

const indexQueue = new JobQueue<IndexJob>()

export async function POST(request: Request) {
  const { marketId } = await request.json()

  // Bloke etmek yerine kuyruğa ekle
  await indexQueue.add({ marketId })

  return NextResponse.json({ success: true, message: 'Job queued' })
}

Loglama ve İzleme

Yapılandırılmış Loglama

typescript
interface LogContext {
  userId?: string
  requestId?: string
  method?: string
  path?: string
  [key: string]: unknown
}

class Logger {
  log(level: 'info' | 'warn' | 'error', message: string, context?: LogContext) {
    const entry = {
      timestamp: new Date().toISOString(),
      level,
      message,
      ...context
    }

    console.log(JSON.stringify(entry))
  }

  info(message: string, context?: LogContext) {
    this.log('info', message, context)
  }

  warn(message: string, context?: LogContext) {
    this.log('warn', message, context)
  }

  error(message: string, error: Error, context?: LogContext) {
    this.log('error', message, {
      ...context,
      error: error.message,
      stack: error.stack
    })
  }
}

const logger = new Logger()

// Kullanım
export async function GET(request: Request) {
  const requestId = crypto.randomUUID()

  logger.info('Fetching markets', {
    requestId,
    method: 'GET',
    path: '/api/markets'
  })

  try {
    const markets = await fetchMarkets()
    return NextResponse.json({ success: true, data: markets })
  } catch (error) {
    logger.error('Failed to fetch markets', error as Error, { requestId })
    return NextResponse.json({ error: 'Internal error' }, { status: 500 })
  }
}

Unutmayın: Backend kalıpları ölçeklenebilir, sürdürülebilir sunucu tarafı uygulamalar sağlar. Karmaşıklık seviyenize uyan kalıpları seçin.

Recommended Agent Skills

Expand your agent's capabilities with these related and highly-rated skills.

affaan-m/everything-claude-code

python-testing

Python testing best practices using pytest including fixtures, parametrization, mocking, coverage analysis, async testing, and test organization. Use when writing or improving Python tests.

132,726 19,206
Explore
affaan-m/everything-claude-code

golang-patterns

Go-specific design patterns and best practices including functional options, small interfaces, dependency injection, concurrency patterns, error handling, and package organization. Use when working with Go code to apply idiomatic Go patterns.

132,726 19,206
Explore
affaan-m/everything-claude-code

e2e-testing

Playwright E2E testing patterns, Page Object Model, configuration, CI/CD integration, artifact management, and flaky test strategies.

132,726 19,206
Explore
affaan-m/everything-claude-code

agentic-engineering

Operate as an agentic engineer using eval-first execution, decomposition, and cost-aware model routing. Use when AI agents perform most implementation work and humans enforce quality and risk controls.

132,726 19,206
Explore
affaan-m/everything-claude-code

api-design

REST API design patterns including resource naming, status codes, pagination, filtering, error responses, versioning, and rate limiting for production APIs.

132,726 19,206
Explore
affaan-m/everything-claude-code

python-patterns

Python-specific design patterns and best practices including protocols, dataclasses, context managers, decorators, async/await, type hints, and package organization. Use when working with Python code to apply Pythonic patterns.

132,726 19,206
Explore

Didn't find tool you were looking for?

Be as detailed as possible for better results