2nd/10_Wiki/Topics/Architecture/Serverless_Architecture.md

---
id: wiki-2026-0508-serverless-architecture
title: Serverless Architecture
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [Serverless, FaaS, Functions-as-a-Service, 서버리스]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [architecture, cloud, serverless, faas]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: typescript
  framework: aws-lambda
---

# Serverless Architecture

## 매 한 줄
> **"매 서버 관리 없이 매 코드 실행 — 매 event-driven, 매 auto-scale, 매 pay-per-use"**. AWS Lambda (2014)로 매 popularize. 2026년에는 매 Lambda + EventBridge + Step Functions, Cloudflare Workers, Vercel Functions, Deno Deploy가 매 생태계 정점. 매 cold-start 문제는 매 SnapStart, Workers V8 isolate로 매 거의 해소.

## 매 핵심

### 매 특성
- **매 No server mgmt**: 매 OS/patching 없음.
- **매 Event-driven**: HTTP, queue, stream, schedule.
- **매 Auto-scale**: 매 0 → 1000s, 매 즉시.
- **매 Pay-per-use**: 매 idle cost 거의 0.
- **매 Stateless**: 매 ephemeral execution.

### 매 trade-off
- **매 Cold start**: 매 ms ~ 수 sec (매 Workers isolate ~ 5ms).
- **매 Vendor lock-in**: 매 AWS-specific event shape.
- **매 Long-running 부적합**: 매 limit (Lambda 15min, Workers 30s CPU).
- **매 Stateful 부적합**: 매 외부 state 필수.

### 매 응용
1. API backend (Lambda + API Gateway).
2. Webhook handler (Workers).
3. Stream processing (Lambda + Kinesis).
4. Cron jobs (EventBridge schedule).
5. AI inference edge (Workers AI, Vercel AI SDK).

## 💻 패턴

### 매 AWS Lambda (TS, SAM)
```typescript
// handler.ts
import type { APIGatewayProxyHandlerV2 } from "aws-lambda";

export const handler: APIGatewayProxyHandlerV2 = async (event) => {
  const body = JSON.parse(event.body ?? "{}");
  return {
    statusCode: 200,
    body: JSON.stringify({ ok: true, echo: body }),
  };
};
```

```yaml
# template.yaml (SAM)
Resources:
  Api:
    Type: AWS::Serverless::Function
    Properties:
      Handler: dist/handler.handler
      Runtime: nodejs22.x
      SnapStart: { ApplyOn: PublishedVersions }  # 매 cold-start ↓
      Events:
        Http: { Type: HttpApi, Properties: { Path: /echo, Method: POST } }
```

### 매 Cloudflare Workers
```typescript
export default {
  async fetch(req: Request, env: Env): Promise<Response> {
    const { pathname } = new URL(req.url);
    if (pathname === "/ai") {
      const r = await env.AI.run("@cf/meta/llama-3.3-70b-instruct", {
        prompt: "Hello",
      });
      return Response.json(r);
    }
    return new Response("ok");
  },
};
```

### 매 Step Functions (orchestration)
```json
{
  "StartAt": "Validate",
  "States": {
    "Validate": { "Type": "Task", "Resource": "arn:aws:lambda:...:Validate", "Next": "Charge" },
    "Charge":   { "Type": "Task", "Resource": "arn:aws:lambda:...:Charge",   "Next": "Notify" },
    "Notify":   { "Type": "Task", "Resource": "arn:aws:lambda:...:Notify",   "End": true }
  }
}
```

### 매 EventBridge schedule
```yaml
Cron:
  Type: AWS::Events::Rule
  Properties:
    ScheduleExpression: "cron(0 * * * ? *)"  # 매 hourly
    Targets: [{ Arn: !GetAtt MyFn.Arn, Id: hourly }]
```

### 매 Vercel Edge Function (RSC)
```typescript
// app/api/hello/route.ts
export const runtime = "edge";
export async function GET() {
  return Response.json({ region: process.env.VERCEL_REGION });
}
```

### 매 Cold-start mitigation
```typescript
// 매 outside handler — 매 init reused across invocations
import postgres from "postgres";
const sql = postgres(process.env.DB_URL!, { max: 1 });

export const handler = async () => {
  const rows = await sql`SELECT NOW()`;
  return rows;
};
```

### 매 Bun + Lambda (2026 trend)
```dockerfile
FROM public.ecr.aws/lambda/provided:al2023
COPY --from=oven/bun:1.2 /usr/local/bin/bun /usr/local/bin/bun
COPY . ${LAMBDA_TASK_ROOT}
CMD ["bun", "run", "handler.ts"]
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| 매 spiky / unpredictable load | Serverless (auto-scale-to-zero). |
| 매 steady high QPS | EC2/Fargate cheaper. |
| 매 long-running batch | Step Functions / Fargate. |
| 매 ultra-low latency global | Workers / Vercel Edge. |
| 매 stateful | 매 외부 state (DynamoDB/Redis). |

**기본값**: 매 API + webhook → Lambda or Workers. 매 latency 중요 → Workers.

## 🔗 Graph
- 부모: [[Distributed Systems]]
- 변형: [[FaaS]]
- 응용: [[API Gateway]] · [[Cloudflare Workers]]
- Adjacent: [[Microservices]] · [[Event-Driven Architecture]] · [[Cold Start]] · [[Scalability]]

## 🤖 LLM 활용
**언제**: 매 event-driven workload, 매 auto-scaling 필요, 매 ops cost ↓.
**언제 X**: 매 long-running compute, 매 strict latency p99, 매 vendor-neutral 강제.

## ❌ 안티패턴
- **매 huge Lambda monolith**: 매 cold-start ↑, 매 cost ↑.
- **매 sync chained Lambdas**: 매 cost double-billing — Step Functions 사용.
- **매 connection pool 매 handler 안**: 매 연결 폭발.
- **매 secret 매 env에 매 plaintext**: 매 Secrets Manager / KMS.
- **매 cold-start 무시**: 매 user-facing path는 매 SnapStart/provisioned.

## 🧪 검증 / 중복
- Verified (AWS Lambda docs, Cloudflare Workers docs, Vercel docs).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — Lambda+SnapStart, Workers, Step Functions patterns |