I built RoastMaster this week

I shipped RoastMaster.

Upload a selfie. Pick Roast or Glaze. Get share-ready banter in seconds.

Live: https://roastmyphoto.app/

Why I built it

I wanted to build something that was:

• fun enough to share
• simple enough to launch quickly
• messy enough to teach me real product lessons
• have some concept of tuning and prompting an AI programmatically

No decks. No fake roadmap. Just build, test, ship.

The stack

Kept this intentionally lean:

• Next.js (App Router)
• Clerk (auth)
• Stripe (one-time credits)
• Neon (Postgres)
• Upstash Redis (free quota/rate-ish controls)
• OpenRouter + Grok-style prompting for outputs
• Vercel deploy + domains

Nothing exotic.

The core product loop

I wanted one loop:

1. Upload image
2. Pick mode + intensity
3. Generate output
4. Copy / share to X
5. Buy credits when free quota runs out

If that loop feels smooth, the product works.

Prompt tuning was the real work

Early versions showed Grok can be truly unhinged. Some top tier roasting, but just word diarrhoea. Too much degen slang, random AI/crypto content - just a mess.

This was also the main point of this build.

The fix was not softening. The fix was constraints:

• keep it savage at high intensity
• one clear punchline per line
• short lines
• force focus on the image
• coherent flow across the full block

Brutal + readable every time.

Launch-day bugs (and what they taught me)

I hit exactly the kind of stuff you only catch in prod:

• Clerk custom domain DNS issues
• Stripe webhook pointed at wrong URL once (fml)
• Large camera uploads hitting Vercel payload limits before server-side compression

I did add compression on the server, but last one was a reminder: server-side compression doesn’t help if the request never reaches your server.

So I added client-side resize/compression before upload. Slightly slower from upload to outcome. But less 'your pic is too big' errors. Acceptable trade-off.

What I’d do differently next time

Honestly not too much. These little fails and bugs are fine when the intention is moving quickly. But if I wanted to be a little more careful then:

• Not setup stripe products and clerk auth on mobile while eating lunch 😏
• Think about image optimisation and vercel limits from day 1
• More prompt tweaking ahead of development.

Where this goes next

Near-term:

• keep improving output quality (especially intensity 4/5)
• tighten share loop and creator UX
• improve analytics around conversion + retention

Longer term:

• more styles, better voice presets
• possibly non photo stuff - roast my cv, roast my job application etc
• better anti-abuse controls
• richer output cards

The takeaway

This is exactly the kind of build I want to keep doing.

Small scope. Real users. Real money flow. Real bugs. Fast feedback.

That loop compounds.

If you test it, send me your output. If it’s mid, I’ll tune it. If it’s savage, post it.