Complete products, shipped in two weeks.

Design, frontend, backend, AI, payments, and app-store deployment — built by one senior developer for a fixed price agreed before anyone starts. Not a prototype and not a demo. The whole working product, live on your domain or in the stores.

Start a project See the work

Sousy

Cookback

Bento Playbox

off my chest

Four products designed, built, and shipped solo — interface, server, AI, billing, and store listings. Every one of them is a client project I gave myself first.

Live store listings

Products shipped solo

iOS · Android
macOS · Web

Platforms delivered

Person you deal with

What you can buy

Two weeks. Fixed price. Shipped.

Three ways to work together, all quoted before the first line of code. Each one is scoped to a single clear outcome — that's what makes a fixed price safe for both of us, and it's why the risk of the estimate being wrong is mine rather than yours.

Most requested

AI Feature Sprint

One meaningful AI capability, inside the product you already have.

$3,000–5,000

Fixed · Two weeks

Chat with your documents, answering from your content and citing it
Messy incoming content turned into reliable structured data
Semantic search across your own customer or catalogue data
An AI-assisted step inside a workflow your team already runs
Evals, spend caps, and a fallback provider, so it holds up in production

For SaaS owners and agencies whose customers have started asking for this.

Product build

Product Sprint

One production product, built around a single primary user journey.

From $7,500

Typically $8–15k · Per scope

One primary journey, written down and agreed before the start
Web, mobile, or both — whichever the product actually needs
Accounts, payments, and store submission quoted as part of that scope
Most ship in one two-week sprint; larger scopes are quoted as two
One revision round included

For founders and owners who need the first real version to exist.

Ongoing

Build Partner

A standing block of capacity on your product.

$2,000–4,000

Per month · Rolling

Two to four days of build capacity every month, prioritised by you
Agreed response times when something urgent breaks
Unused capacity expires monthly — no alarming backlog to settle
The person who built it is the person improving it
Stop with 30 days' notice, no lock-in

Starts after any sprint, once you know what the next version should be.

The two weeks, hour by hour

You see it running on day three.

Fixed-price work goes wrong when the client can't see anything until the end. So there's a deployed link in your hands early, and it updates as the build goes. Ten working days, two demo videos, one revision round — the plan you're buying, not a promise to be agile.

Scope & kickoff

One call, then a feature list we both sign.

Day 1

Interface & core build

The screens and the data model — the parts you'll actually touch.

Days 2–6

AI, payments, integrations

The features carrying the risk, built early on purpose.

Days 4–8

Polish & your revisions

Your notes from the week-one demo, applied.

Days 7–9

Deploy & handoff

Live on your domain or submitted to the stores. Yours.

Day 10

A deployed preview link lands on day three and stays current for the rest of the sprint. Demo videos arrive at the end of each week, so reviewing the work never depends on finding a meeting slot.

Selected work

Everything here was built by one person.

Four products, each taken from empty repository to store listing: interface design, backend, AI, subscriptions, review submissions, and the marketing page you land on. Different stacks, because different products deserve different answers.

Sousy

iOS · Android · Web

An AI cooking assistant that turns a TikTok, YouTube, or Instagram link into a structured recipe you can actually cook from.

Video and blog links parsed into clean, structured data
Two AI providers with automatic failover, so one outage isn't downtime
Stripe, Apple, and Google billing behind one subscription model
Nine languages, home-screen widgets, and an embeddable recipe widget

Live · App Store & Google Play sousy.com →

Cookback

iOS · Android · Apple Watch

A cooking journal that remembers for you — and can answer questions about your own cooking history.

Retrieval over your personal history, scored by an eval suite before any prompt ships
Works offline first, mirrored privately through iCloud
No accounts at all — abuse protection via Apple App Attest instead
Live Activity, Dynamic Island, and a Watch app for an active cook

Live · App Store & Google Play cookback.app →

Bento Playbox

iOS · Android · Paid app

A Montessori-style activity app for ages two and up, with nine toys and not a single dark pattern.

Two hand-written native builds — SwiftUI and SpriteKit, Jetpack Compose
559 licensed voice clips, loudness-matched through a scripted pipeline
A 176-food catalogue generated and bundled, so it works offline
No backend, no accounts, no ads, no tracking — one $2.99 purchase

Live · App Store & Google Play sousy.com/games →

off my chest.

iPhone · iPad · Mac · Android

A writing app where the words burn away as you type. Nothing is saved, sent, or recoverable.

Custom text rendering: words ignite, wash, crumble, or drift off as fireflies
Seven moods, each with its own paper, ink, and pace
Zero backend, zero analytics, two dependencies in the whole app
One codebase across four platforms, including a real Mac build

Live · App Store, Mac & Google Play getitoffmychest.app →

How the work runs

Why the fixed price holds.

A fixed quote is only safe for both of us if the edges are drawn before we start. These are in every agreement, and they're the reason the date on the quote is the date you get it.

Scope

A signed feature list, before day one

One page, in plain language, that we both approve. It's what the price is attached to, and it's what "done" means.

Payment

Half up front, half on delivery

Invoiced through Stripe. No hourly billing, no surprise overage, no meter running while you think.

Revisions

One round included

Collected after the week-one demo, when changes are still cheap. Further rounds are quoted like any other work.

Contact

Two calls, two demo videos

A kickoff call and a handoff call. In between, a recorded demo each week and a live preview link — so progress is visible without standing meetings.

Changes

New ideas get a number and a date

Nothing is refused. Anything outside the signed list comes back as "that's $X and adds Y days," and you decide.

Ownership

The code is yours at handoff

Full ownership, in your repository and your accounts. White-label terms available if you're an agency delivering it as your own.

For agencies and design studios

Overflow capacity that never talks to your client.

If you've sold work you can't staff this month, hand me a clearly scoped piece of it and I'll disappear into the background. You keep the relationship, the margin, and the credit.

White-label by default

I don't contact your client and my name doesn't appear anywhere. The work ships as yours.

Your margin is known up front

A fixed quote per project, before you commit to your own client. No hourly drift eating the difference.

Demos you can forward

A recorded demo each week and a live preview link — send them on as your own progress update.

Built for design-led studios

Particularly useful if you sell beautiful product design and don't employ application engineers.

Talk about overflow

Happy to start with one small project to see whether we work well together.

The whole stack

"Complete" means you don't have to hire anyone else.

Product & interface

Interface and interaction design
Design systems and iconography
React and Next.js on the web
Native iOS — Swift and SwiftUI
Native Android — Kotlin and Compose
Flutter for one codebase, four platforms
Marketing pages and store listings

Backend & infrastructure

TypeScript APIs on AWS, defined as code
Serverless functions, queues, and storage
SQL and DynamoDB data modelling
Accounts, sign-in with Apple and Google
Offline-first sync and local storage
Monitoring, alerting, and cost control
CI, staged environments, release pipelines

AI & money

Claude and OpenAI, with failover between them
Retrieval over your own documents and data
Extraction: messy sources to structured records
Evaluation harnesses, so quality is measured
Token budgets and spend guardrails
Stripe subscriptions and one-off payments
App Store and Google Play billing

Who you'd be working with

Sousy Studio is Nick Schirmer.

One senior full-stack developer, not a team you'll never meet and not a queue of junior contractors behind an account manager.

I've spent years building software professionally, and the last stretch of it shipping four of my own products end to end — which is a different skill from writing code well. It means picking what to leave out, getting through app review, wiring up billing that reconciles, and being the one who notices the empty state looks sad. Every project on this page went through that alone.

That's what you're hiring: someone who has taken the whole distance more than once, and who quotes a fixed price because he knows how long it actually takes.

Next step

Tell me what you're trying to launch.

A paragraph is plenty. I'll reply with whether it fits a sprint, what it would cost, and when it could ship — usually within a day, and without a discovery call first.

nick@sousy.com

Currently taking one to two projects a month. Agencies and studios — start here.