Updated August 27, 2026 · 8 min read · Written by ProposalAI

Full-Stack Proposal Example (Marketplace MVP With Two Roles)

When the post asks for buyers, sellers, admin, and payments, a good proposal names a first slice instead of agreeing to the entire product at once.

Example job situation

A founder wants a two-sided marketplace: buyers browse listings, sellers onboard, admin approves listings. They mentioned Next.js and PostgreSQL. Payments “can be later.” The budget is modest. They asked what you would ship in the first two weeks.

Weak / generic proposal

I am a full-stack developer. I can build your entire marketplace with Next.js, Node, MongoDB, Stripe, AWS, and AI recommendations. I have built Uber-like and Airbnb-like apps.

I will deliver a complete product with all features. 100% satisfaction guaranteed.

Why this is weak

  • It inflates scope (AI, Uber-like) and ignores “payments later.”
  • MongoDB conflicts with the PostgreSQL they named, with no reason.
  • Two weeks for a complete marketplace is not a plan; it is a hope.

Improved proposal

Hi — for a two-week first slice I would ship buyer browse + seller listing draft + admin approve/reject on Next.js and PostgreSQL, with email/password auth and no payments yet, matching what you wrote.

I built a similar listing-approval flow for a small services directory: public cards, seller form with image upload, and an admin queue. Payments were a later milestone so we did not block launch on Stripe.

I would not introduce MongoDB here. Postgres fits the relational listing/approval model you already chose.

What is the minimum listing field set (title, price, photos, location)? And should sellers see a public profile in week two, or only after a listing is approved?

Why this is stronger

  • It answers the two-week question with a cut line.
  • It respects “payments later” instead of upselling Stripe immediately.
  • It stays on their database choice and explains why.

Personalization points

  • Repeat their stack. Do not silently swap it.
  • Name what is out of scope for week two so they can correct you.
  • If they already have Figma, say you will implement, not redesign.

Questions you could ask

  • Minimum listing fields?
  • Are buyers allowed to contact sellers before payments exist?
  • Who hosts images — your S3, or should we start with a simple upload path?

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