Shipping a production-ready MVP in 3-5 days as a solo developer: the pipeline I actually use

I run a one-person software company. No team, no agency, no project manager — just me and a terminal. People usually assume that means small scope: a landing page, a prototype, something that "works for now".

In practice the last few months shipped a crypto market-analysis web app, a cross-platform turn-based artillery game (Android + iOS + a Toss mini-app), and client MVPs for small businesses. Client projects go from kickoff to a deployed URL in 3–5 days.

This is the pipeline that makes that possible — the parts that actually matter, and the parts people get wrong.

1. Define the one loop the product must close

Before touching code I write one sentence: "A user can do X, get Y, and come back." Everything else is out of scope.

For a client MVP the first loop is usually: sign up → do the one valuable action → see the result saved. If a feature does not touch that loop, it goes on the v2 list. Being able to say no to scope on day one is the biggest speed factor — bigger than any framework choice.

2. The stack I reuse instead of rebuilding

• Frontend: Next.js (App Router) + Tailwind CSS
• Backend: FastAPI (Python) when there is data, scraping or AI work; Next.js route handlers when there is not
• DB + auth: Supabase (Postgres, row-level security, email and OAuth auth)
• Mobile: Flutter for cross-platform builds, or a Toss mini-app when the user will never install an app
• Background work: one Playwright / ffmpeg worker process, not a queue cluster

Every choice here exists to remove a decision. I do not want to spend day two comparing auth providers; I want to spend it on the loop.

3. Deploy on day one, not day five

The first deploy happens before the second feature: empty page, real domain, environment variables wired. Deploying early turns integration risk into a non-event.

I also keep a fixed layout shell per project type — dashboard, marketing page plus app, admin table. The client clicks a real URL on day one, and the conversation moves from "when will it be done" to "what should this screen say".

4. Automate the work a one-person team cannot afford to repeat

A solo team cannot absorb meetings and manual repetition, so the boring parts get scripted:

• Data collection: Playwright scripts with retries and conservative throttling, writing into a typed schema. Respecting rate limits is cheaper than fighting them.
• Content pipeline: for the crypto app, a confirmed headline triggers an HTML template render to a 27-second vertical video through ffmpeg — unattended, from headline to final file.
• Release: push, build, deploy to Netlify or Vercel. One command, same for me and the client.

The rule: if I click the same thing twice in a week, it becomes a script.

5. Where AI agents actually help, and where they do not

I use an agent for the well-specified, parallel work: writing the CRUD layer for a schema I designed, turning an API response into typed models, drafting a migration, generating form UI, and a first pass at release notes. That is real time saved.

Agents are weak exactly where the product is decided — the data model, what the first loop is, which edge case will hurt the client's business. Handing those off is how you get a fast, wrong product.

Two rules I keep:

1. Give the agent the schema and the exact file, not the whole repo and a wish.
2. Never merge output you cannot explain line by line to the client.

6. The last 10% is the whole product

A deployable MVP is not a shippable one. The 3–5 day budget always keeps a fixed block for: error states, empty states, a real 404, loading skeletons, one scheduled database backup, password reset, and a smoke test right after deploy. Clients never notice when these exist. They notice within a minute when they do not.

What this is not

It is not "AI builds your app". It is a small set of boring decisions reused until they are fast, with automation around the parts a human should not repeat. The speed comes from refusing to re-decide things that are already decided.

I run this as a one-person studio in Seoul — case studies and what I build for clients are at https://cpcai-studio.netlify.app/en/. If you are sitting on a half-built repo and a deadline, ask in the comments; I am happy to talk specifics about scope, stack or estimates.