replit-architecture-variants

# Replit Architecture Variants ## Overview Application architectures on Replit at three scales: single-file prototype, modular production app, and multi-service architecture. Each matches Replit's container model, built-in services, and deployment types. ## Prerequisites - Replit account - Understanding of deployment types (Static, Autoscale, Reserved VM) - Familiarity with Replit's storage options ## Architecture Decision Matrix | Factor | Single-File | Modular App | Multi-Service | |--------|------------|-------------|---------------| | **Users** | Prototype, < 100/day | 100-10K/day | 10K+/day | | **Database** | Replit KV (50 MiB) | PostgreSQL | PostgreSQL + cache | | **Storage** | Local + KV | Object Storage | Object Storage + CDN | | **Persistence** | Ephemeral OK | Durable required | Durable required | | **Deployment** | Repl Run / Autoscale | Autoscale / Reserved VM | Multiple Reserved VMs | | **Cost** | Free-$7/mo | $7-25/mo | $25+/mo | | **Always-on** | No (free), Yes (deploy) | Yes (deployment) | Yes (deployment) | ## Instructions ### Variant A: Single-File Script (Prototype) **Best for:** Bots, scripts, learning, hackathon projects. ```python # main.py — everything in one file from flask import Flask, request, jsonify from replit import db import os app = Flask(__name__) # KV Database for simple state @app.route('/') def home(): count = db.get("visits") or 0 db["visits"] = count + 1 return f"Visit #{count + 1}" @app.route('/api/notes', methods=...