fastapi-full-stack-template — System Workflow

Component communication map · concurrent request capacity · bottleneck analysis · 2026-07-09

API Worker Processes

1 workers × 1 replica(s)

~100

Max Concurrent Async I/O

~100 per asyncio worker

~100 concurrent I/O

Practical Throughput

bottleneck: I/O event loop

Capacity figures are static-analysis estimates (heuristic: ~100 concurrent tasks per async worker), not load-test results.

Full System Architecture — 5 Components

EXTERNAL SOURCES & CLIENTS

GitHub

Webhooks + API

HMAC-SHA256

Users / API Clients

HTTPS / WebSocket

JWT

↓

GATEWAY / REVERSE PROXY

nginx

worker_connections ?

TLS termination

↓

APPLICATION LAYER

FastAPI

async 1 worker × 1 replica

jwt · oauth

React

UI framework

↓

PROCESSING & QUEUE LAYER

Auth Middleware

JWT decode · RBAC scope check

↓

STORAGE & PERSISTENCE

PostgreSQL

Primary database

Detected API Routes (10+)

DELETE /me

DELETE /{id}

DELETE /{user_id}

GET /

GET /health-check/

GET /me

GET /{id}

GET /{user_id}

PATCH /me

PATCH /me/password

Data Flow Paths — Step by Step

Write Path — Webhook Ingestion

GitHub fires webhook

POST to /me. Signature verified immediately.

HMAC-SHA256

Instant acknowledgment

API returns 202 immediately — processing continues async in event loop

202 Accepted

Concurrency Model — Layer by Layer

Layer	Concurrency Model	Ceiling	Limiting Factor
Nginx / Gateway	Event-driven (epoll)	1024 connections	worker_connections · no rate limit detected
FastAPI / App Server	asyncio event loop	~100 concurrent I/O	1 × 1 = 1 workers

Bottleneck Analysis — Where the System Saturates First

Network I/OLOW

Event-loop driven I/O is efficient. Scale workers horizontally to increase throughput.