Pillar one · Apps to production

A Fractional CTO
for your AI-built MVP

You vibe-coded a prototype that mostly works. The Notus is the fractional CTO and MVP development team that finishes it the right way and ships it to real users. Fixed scope, fixed price, from $7,500 in 3 to 4 weeks. You own the code.

001 / The production gap

What AI tools leave unbuilt

The last 20% that decides whether it ships

AI builders are genuinely good at the first 80%. They produce a working screen flow, a plausible schema, and a demo that looks like a product. The last 20% is the part that decides whether real users can trust it with their money and their data, and it is the part those tools quietly skip.

That gap is where prototypes stall. The auth half-works. The Stripe webhook fires twice and double-charges. The AI feature calls a model on every keystroke and the bill arrives. The database has no indexes and falls over at fifty rows. We close that gap, end to end.

The production layer we add
002 / How it works

Audit · Fixed scope · Weekly review · Handoff

One bill, then it's yours
01

Free 48-hour audit

Send the repo, the URL, or just the idea. Within 48 hours we send back a written read on exactly what it takes to get to production. No call required, no cost, no obligation.

02

Fixed scope and price

You get one number and one scope before any work begins. From $7,500. No hourly billing, no retainer, no scope-creep surprise invoices. You approve it, then we start.

03

Weekly review

We build in 3 to 4 weeks with a review every week, so you see real progress on a running app and never wonder where the work is. Direction stays with you; the engineering and AI-model calls are ours.

04

Handoff, you own it

We hand off the full source code with a plain-English walkthrough. You own everything: no platform lock-in, no subscription to us. Your team, or you and Claude, keep building from there.

003 / Proof

Song Cage · Founder vision to shipped

Designed and built from a blank file
Case study · Music / AI SaaS

#1 in ChatGPT for "best songwriting app" within 7 days of launch.

Song Cage came to us as a founder vision with no prototype to start from: no architecture, no melody-detection algorithm chosen, no plan to keep web, iOS, Android, and a DAW plugin in sync, no billing. We took the fractional CTO seat and designed and built the whole product from a blank file. One React codebase ships to the web, to the App Store and Google Play via Capacitor, and inside DAWs as an AU/VST3 plugin.

It went live with the unglamorous infrastructure that decides whether a product holds: PowerSync offline-first sync, a custom pitch-detection pipeline, Stripe reverse-trial billing, and an AI-legible marketing site. 92 users signed up in the first month with zero ads. ChatGPT began recommending Song Cage #1 for "best songwriting app" within seven days of launch, with Perplexity and Claude citing it in the same window.

Read the Song Cage case study →
92
Signups · month one · zero ads
#1
ChatGPT: "best songwriting app"
7
Days from launch to first AI citation
004 / Fractional vs full-time

When to hire which

A budget question, not a status question
Hire a fractional CTO when
Hire a full-time CTO when
005 / Questions

Fractional CTO FAQ

Price, speed, equity, ownership

What does a fractional CTO cost?

Our Apps to Production engagement starts at $7,500 for a fixed scope, typically delivered in 3 to 4 weeks. It is one bill, not a retainer or hourly arrangement. After the free 48-hour audit we send a fixed scope and a fixed price, so you know the total before any work starts. There are no surprise invoices and no platform subscription to us.

Can you take my Lovable or Cursor MVP to production?

Yes. That is the core of this service. We finish AI-built prototypes from any vibe-coded stack: Lovable, Cursor, Claude, Bolt, Replit, v0, and Windsurf. We add the production layer those tools skip: auth, payments and webhooks that hold under real traffic, AI cost controls, a database designed to scale past ten users, security and row-level security, and a real performance budget. You own the code outright at the end.

Do you take equity?

No. We work for a fixed fee on a fixed scope, not equity. You keep full ownership of your company and your code. We are not a co-founder substitute and we are not a retainer. We finish the production work, hand it off, and you own everything we built.

How fast can you ship?

Most Apps to Production engagements ship in 3 to 4 weeks from the day scope is signed. The free audit comes back within 48 hours. After that you get a fixed scope and price, then a weekly review while we build, then a clean handoff. Greenfield builds with no prototype yet take longer and are quoted separately.

When should I hire a fractional CTO instead of a full-time one?

Hire fractional when you have a defined goal — get this AI-built MVP to real users — and a fixed budget, not an open-ended headcount need. A full-time CTO makes sense once you have a team to lead, ongoing architecture decisions every week, and revenue to support a senior salary. Before that, a fixed-scope fractional engagement gets you to production for a fraction of the cost, with no equity given up and no long-term commitment.

What do I actually get at the end?

You get a production application running on real infrastructure, the full source code, and ownership of all of it. No platform lock-in, no SaaS subscription to us, no retainer. We hand off the repo with a plain-English walkthrough so your team, or you and Claude, can keep building after we leave.

006 / Also from The Notus

Two pillars, one shop

When you need the other side
Pillar two · From $4,000

Website redesign & rebuilds →

Migrations off Webflow, WordPress, Squarespace, and Wix into custom Astro on Cloudflare. Productized, fast, and AI-legible from line one.

Greenfield · From $4,000

Custom website development →

A brand-new custom site built end to end by our team: brand, design, and engineering, structured for ChatGPT, Perplexity, and Google AI to cite.

Send us your repo

We'll tell you exactly what it takes to ship it.

Free written estimate in 48 hours. No call required.

Get a free audit →