AI SaaS Product বানানো — মেশিন লার্নিং

Hook — Model থেকে Business

Model accuracy ৯৫% মানে কিছু না, যদি কেউ টাকা না দেয়। AI SaaS মানে ML কে subscription product এ রূপান্তর — auth, billing, quota, UX, support — সব মিলিয়ে।

Idea Validation

Painful, frequent, paid problem খুঁজো।
Niche বাছো — ‘AI for X’ (lawyer, real estate, e-commerce)।
Landing page → waitlist → 50 signup before code।
Customer interview ১০+ — তারা আজ কী use করে?

Tech Stack (Lean)

stack

Frontend:  React + Tailwind + shadcn/ui
Backend:   FastAPI / Next.js routes
Auth:      Supabase / Clerk
DB:        Postgres (Supabase / Neon)
Vector:    pgvector
LLM:       OpenAI / Claude / open-source via Modal
Queue:     Redis + RQ / Celery
Billing:   Stripe (subscriptions + metering)
Hosting:   Vercel / Fly.io / Cloudflare
Monitor:   Sentry + PostHog

Reference Architecture

diagram

Browser
  ↓
Next.js (UI + edge routes)
  ↓
FastAPI workers ──→ LLM provider
  │             ──→ Vector DB
  ↓
Postgres (users, jobs, usage)
  ↓
Stripe webhook → update plan / quota

Auth + Multi-tenant

Supabase Auth (email + Google + GitHub)।
Row-Level Security — `user_id = auth.uid()`।
Workspace/team table — invite via email।
Roles separate table (`user_roles`) — never store role on profile।

Billing — Stripe Pattern

webhook.py

@app.post("/api/stripe/webhook")
async def webhook(req: Request):
    event = stripe.Webhook.construct_event(
        await req.body(), req.headers["stripe-signature"], WEBHOOK_SECRET
    )
    if event["type"] == "customer.subscription.updated":
        sub = event["data"]["object"]
        db.update_user_plan(sub["customer"], sub["items"]["data"][0]["price"]["id"])
    return {"ok": True}

Plans: Free, Pro, Business — clear feature gate।
Usage metering: token spend, credit balance।
Hard cap before surprise bill।
Failed payment → grace period → downgrade।

Cost Control

Per-user daily quota (DB column বা Redis counter)।
Cheaper model default, premium upgrade এ বড় model।
Cache: exact + semantic — 30–60% call বাঁচায়।
Batch background job for non-realtime।
Per-tenant cost dashboard — কে কত খরচ করল।

AI UX Best Practice

Streaming response — token দিয়ে token।
Skeleton + progress — wait কখনো silent না।
Edit + regenerate button।
Show source / citation — trust বাড়ায়।
Empty state এ example prompt।
Mobile-first responsive।

Launch Checklist

Landing page + pricing + demo video।
Product Hunt + Hacker News ‘Show HN’।
Twitter/LinkedIn build-in-public thread।
Free trial বা freemium funnel।
Analytics: signup → activation → paid conversion।
Support: Crisp/Intercom + docs site।

Growth Loops

Shareable output (watermark / referral link)।
Template gallery → SEO landing pages।
Affiliate / partner program।
Weekly changelog email — retention বাড়ায়।
User feedback → public roadmap (Canny)।

Summary

এক নজরে

AI SaaS = Niche problem + Lean stack + Auth + Stripe + Cost control + AI-native UX। Model নয়, distribution জিতে। Ship fast, talk to users, iterate weekly।