Project Scaffolding

When to Use

•User says "build me X", "create a new project", "start a project"
•Questions about monorepo vs single package
•Database selection discussions
•Project structure decisions

Database Selection

code

Is this TypeScript-only?
├─ Yes: Do you need realtime/reactivity?
│  ├─ Yes: Is DX priority over control?
│  │  ├─ Yes → Convex (managed, realtime, auth, file storage built-in)
│  │  └─ No → Postgres + Drizzle + websockets/SSE
│  └─ No: Is data local-first or single-user?
│     ├─ Yes → SQLite + Drizzle (or libsql for sync)
│     └─ No: Serverless/edge deployment?
│        ├─ Yes → Turso (libsql) + Drizzle
│        └─ No → Postgres + Drizzle
└─ No (Python involved):
   → Convex excluded (no Python SDK)
   → Is data local-first or single-user?
      ├─ Yes → SQLite
      └─ No → Postgres

Database Quick Reference

Database	Best For	Avoid When
Convex	TS-only, realtime, rapid prototyping, LLM apps	Python needed, want SQL control, cost-sensitive at scale
SQLite	Local-first, CLI tools, single-user, embedded	Multi-writer, high concurrency, need sync
Turso (libsql)	Edge/serverless, SQLite with sync, preview envs	Need raw Postgres features, complex transactions
Postgres	Multi-service, complex queries, proven reliability	Simple local apps, edge without pooling

ORM Choice

TypeScript: Drizzle (not Prisma) Python: SQLAlchemy 2.0 or raw SQL with asyncpg

Project Shapes

1. CLI Only

Single package, no monorepo overhead.

TypeScript:

code

my-cli/
├── package.json
├── tsconfig.json
├── src/
│   ├── index.ts        # Commander.js entry
│   ├── commands/       # Command implementations
│   └── lib/            # Shared utilities
└── dist/

Python:

code

my-cli/
├── pyproject.toml
├── src/
│   └── my_cli/
│       ├── __init__.py
│       ├── main.py     # Typer entry
│       ├── commands/   # Command implementations
│       └── lib/        # Shared utilities
└── tests/

2. CLI + Database

Still single package. Add Drizzle/SQLAlchemy.

TypeScript:

code

my-cli/
├── package.json
├── tsconfig.json
├── drizzle.config.ts
├── src/
│   ├── index.ts
│   ├── commands/
│   ├── db/
│   │   ├── index.ts    # Connection
│   │   ├── schema.ts   # Drizzle schema
│   │   └── migrations/
│   └── lib/
└── dist/

Python:

code

my-cli/
├── pyproject.toml
├── alembic.ini
├── src/
│   └── my_cli/
│       ├── __init__.py
│       ├── main.py
│       ├── commands/
│       ├── db/
│       │   ├── __init__.py
│       │   ├── models.py
│       │   └── migrations/
│       └── lib/
└── tests/

3. Web App + Database (Single Package)

No monorepo for simple full-stack apps.

TypeScript (Next.js + Drizzle):

code

my-app/
├── package.json
├── next.config.js
├── drizzle.config.ts
├── src/
│   ├── app/            # Next.js app router
│   ├── components/
│   ├── db/
│   │   ├── index.ts
│   │   ├── schema.ts
│   │   └── migrations/
│   └── lib/
└── public/

TypeScript (Convex):

code

my-app/
├── package.json
├── convex/
│   ├── schema.ts       # Convex schema
│   ├── functions/      # Backend functions
│   └── _generated/
├── src/
│   ├── app/
│   └── components/
└── public/

4. CLI + Web App + Database

Now you need separation. Monorepo time.

TypeScript (Turborepo):

code

my-project/
├── package.json
├── turbo.json
├── packages/
│   ├── db/             # Shared Drizzle schema + client
│   │   ├── package.json
│   │   ├── src/
│   │   │   ├── index.ts
│   │   │   ├── schema.ts
│   │   │   └── client.ts
│   │   └── drizzle.config.ts
│   └── shared/         # Shared types, utils
│       ├── package.json
│       └── src/
├── apps/
│   ├── web/            # Next.js app
│   │   ├── package.json
│   │   └── src/
│   └── cli/            # Commander.js CLI
│       ├── package.json
│       └── src/
└── tooling/            # Shared configs
    ├── eslint/
    └── typescript/

Python:

code

my-project/
├── pyproject.toml      # Workspace root
├── packages/
│   ├── core/           # Shared business logic + DB
│   │   ├── pyproject.toml
│   │   └── src/core/
│   │       ├── db/
│   │       ├── models/
│   │       └── services/
│   └── shared/         # Shared types, utils
├── apps/
│   ├── api/            # FastAPI
│   │   ├── pyproject.toml
│   │   └── src/api/
│   └── cli/            # Typer
│       ├── pyproject.toml
│       └── src/cli/
└── tests/

Mixed Python + TypeScript:

code

my-project/
├── package.json        # Root for TS tooling
├── turbo.json
├── pyproject.toml      # Root for Python workspace
├── packages/
│   └── shared-types/   # Generated types (TypeScript)
├── apps/
│   ├── web/            # Next.js (TypeScript)
│   ├── api/            # FastAPI (Python)
│   └── cli/            # Typer (Python)
└── tooling/

5. Multiple Web Apps

Turborepo with shared packages.

code

my-project/
├── package.json
├── turbo.json
├── packages/
│   ├── ui/             # Shared component library
│   ├── db/             # Shared database
│   └── shared/         # Shared utils, types
├── apps/
│   ├── web/            # Main app
│   ├── admin/          # Admin dashboard
│   └── docs/           # Documentation site
└── tooling/

Backend Framework Selection

code

TypeScript API:
├─ Simple REST, few endpoints → Hono (lightweight, edge-compatible)
├─ Standard API, moderate complexity → Express + tRPC
└─ Complex, needs DI/modules/guards → NestJS

Python API:
└─ Always FastAPI (async, typed, fast, good DX)

When NOT to Use Monorepo

•Single CLI tool
•Single web app (even with DB)
•Prototype/MVP
•Solo project that won't grow

Monorepo overhead isn't free. Don't add it speculatively.

Turborepo Setup Notes

bash

# Create new turborepo
npx create-turbo@latest

# Or add to existing
npm install turbo --save-dev

Key turbo.json tasks:

json

{
  "tasks": {
    "build": {
      "dependsOn": ["^build"],
      "outputs": ["dist/**", ".next/**"]
    },
    "dev": {
      "cache": false,
      "persistent": true
    },
    "lint": {},
    "typecheck": {}
  }
}

Python Monorepo with uv

toml

# Root pyproject.toml
[tool.uv.workspace]
members = ["apps/*", "packages/*"]

bash

# Run command in specific package
uv run --package api uvicorn api.main:app

# Add dependency to specific package
uv add --package cli typer