Putera Kahfi - Full Stack Developer & SaaS Builder

🧊

Never initialize external clients at the top level. Next.js hates it during build. Always use getters.

private getClient() {
  return createClient(...) 
}

🛡️

Environment variables are ghosts during build time. Always provide a fallback to prevent the "undefined" crash.

const url = process.env.URL || '...'

📜

Updating the UI? Update the Entity first. In a monorepo, the Domain is the source of truth for every team.

interface TenantEntity {
  details: { ...newField }
}

🏗️

Keep features logically separated but physically close. Each module (Billing, Auth, Tenant) stays independent within the monorepo.

packages/bounded-contexts/billing
packages/bounded-contexts/auth

🧱

Follow the flow: Infrastructure depends on Application, and Application depends on Domain. Never the other way around. Keep your Domain pure.

Domain → Application → Infrastructure

♻️

Stop repeating yourself. Build it once in @repo/ui or @repo/domain and consume it across 10+ different SaaS apps.

import { Button } from "@repo/shared-ui";

💉

Don't use new Service() in your components. Inject them via IoC Container for better testability and decoupled logic.

container.get<TenantService>(TYPES.TenantService)

🧙‍♂️

TypeScript is your friend, not your jailer. Use any sparingly to bridge build inconsistencies, but always target explicit types.

const shadow = raw as any;

📡

Bridge your client and server with 100% type safety. No more manual API fetching; just call your procedures like local functions.

trpc.tenant.get.useQuery({ id })

⚙️

Keep your Tailwind, TypeScript, and ESLint configs in one place (packages/config-*). Update once, reflect everywhere.

extends: ["@repo/config-eslint"]

Mastering the
Monorepo.