Mustafa Dualeh

MVPs, payment flows and AI features. Built to hold up.

I'm a full-stack product engineer for startups and small teams. I spent nine years shipping Android and web products in Japan: at Nissan, at Daimler Trucks Asia, and as the sole developer of an Android browser with 100,000 downloads. Today I build with AI coding agents under strict review and test rules. That lets me move fast without skipping the parts that keep software reliable.

Start a project Read the Tinkr case study

What I can build for you

Three fixed-scope offers, each with a written plan, a weekly demo and a handover your team can maintain.

  1. MVP and v1 product builds

    For founders and small businesses with a validated idea who need a working product, not a slide deck.

    • Scoped feature list and data model before any code
    • Web app, API and Postgres database with auth
    • Stripe payments, admin panel and transactional email
    • Tests on the money and data paths, CI/CD and a handover guide

    USD 4,500

    core MVP, fixed price; scoping sprint USD 600

    Typically 4–8 weeks

  2. Payments and integrations

    For SaaS products and marketplaces whose orders get stuck, webhooks fail silently, or refunds and payouts are manual.

    • Stripe Checkout with signature-verified webhooks
    • Reconciliation against Stripe, so your database matches reality
    • Idempotent order creation, refunds, coupons, multi-currency
    • Payout and third-party API integrations

    USD 600

    payments audit; builds from USD 2,000

    Audit 3–5 days · build 1–3 weeks

  3. AI feature integration

    For teams who want one useful AI feature in an existing product, without runaway costs or unpredictable output.

    • Claude or OpenAI behind your backend, never in the browser
    • Structured output validated against a schema
    • Safe failure, rate limits, bot protection and daily spend caps
    • A small evaluation set, so quality is measured, not assumed

    USD 900

    one-week prototype; production from USD 2,500

    Prototype 1 week · production 1–3 weeks

After a first project: a monthly retainer for 10–25 hours a week. Also available for Android and Kotlin maintenance.

Featured work: Tinkr Doodles

A parent photographs a child's drawing. A few minutes later they can spin a 3D figurine of it, choose the colours and order a print made by a local maker. One of the apps I built on Tinkr, my startup.

  1. Doodles landing screen on a phone, headed 'From crayon to keepsake.'

    01 Start

  2. Upload screen with options to take a photo or choose one from the library.

    02 Add the drawing

  3. Progress screen reading 'Making the magic' while the 3D model is generated.

    03 Generate the model

  4. 3D preview of a four-colour figurine of a girl with pigtails, with size and colour options.

    04 Preview, size and colours

FIG. 1 Local build in demo mode. Step 4 shows a real generated model and its exact four-colour print plan.

Under the hood

  • Every upload is screened by a vision model before anything is generated
  • Drawing to 3D model through an image-to-3D provider, with automatic fallback and a daily budget
  • Colours reduced to up to four printable filaments and written as a multi-colour print file
  • The card is held at checkout and charged only when a local maker accepts the job
  • Passwordless sign-in, bot protection and an augmented-reality preview on phones
Read the Tinkr case study

A full technical version is available to hiring managers and clients on request.

Product
Tinkr Doodles, part of Tinkr
Role
Founder & technical lead
Stack
React, three.js / model-viewer, Cloudflare Workers, Postgres, Stripe
AI
Claude vision screening, image-to-3D generation
Status
Pre-launch · private beta

Built as a platform

Doodles is one app on Tinkr. The same API runs MakerChip and the hosted checkout, and is designed for partners who want to send print jobs into the provider network from their own products.

Apps
Tinkr DoodlesMakerChipCheckout Partner apps
each app has its own registered keys and checkout settings
Platform
Tinkr APIQuotes and orders PaymentsSigned webhooks
jobs are matched by country, materials and capacity
Network
Independent print providersCloud slicing Provider payouts

App registry

Every app, first-party or partner, is registered with its own keys, allowed origins and checkout return address, and can be paused on its own without touching the others.

Partner API

Sandbox and live keys, quotes and orders, a hosted checkout handoff, audience-filtered OpenAPI docs and signed webhooks with retries.

Developer tools

A TypeScript SDK, a sandbox that steps orders through every stage, and an AI build brief partners paste into their own coding agent.

Partner hub docs page with an AI build brief to copy into a coding agent and a TypeScript SDK download.
FIG. 2 Partner hub: TypeScript SDK and an AI build brief for coding agents. Test data.
Partner webhook endpoints list showing subscribed events, delivery attempts and status.
FIG. 3 Webhook endpoints with signed deliveries and retry limits. Example data.

Pre-launch: the partner API is built and documented, with no external partners live yet.

Experience

Connected-car apps for a global carmaker, internal tools for a truck manufacturer, a browser built solo, and now my own platform. B.A. Computer Science, York University, Toronto.

  1. 2026 — now

    Founder & technical lead

    Tinkr (Tinkr App Ltd, UK) · Remote

    • Pre-launch 3D-printing platform: API, four React apps, cloud slicing, Stripe payments and provider payouts.
    • Defined the product and architecture, and directed AI coding agents under written review and testing rules, approving every merge.

    Status Pre-launch, private beta

  2. 2020 — 2025

    Android engineer

    Nissan Motor Corporation · Tokyo

    • Built a camera-based Digital Driver's Guide prototype with TensorFlow Lite transfer learning, ML Kit and CameraX.
    • Shipped features for the Nissan Connect Android app and worked with the Android Automotive Car SDK. Introduced unit testing and contributed to the consolidated Flutter app.

    Stack Kotlin, Jetpack, Flutter, TF Lite

  3. 2018 — 2020

    Full-stack developer

    Daimler Trucks Asia (FUSO) · Kawasaki

    • Built internal Kotlin/Spring Boot and React applications: a quiz platform, truck-driver tracking, and the web front end of a bus-tracking proof of concept later used by staff and clients.
    • Taught a three-month introductory programming course in Kotlin to non-developers.

    Stack Spring Boot, Kotlin, React

  4. 2017 — 2018

    Lead Android engineer

    Astool Inc. · Tokyo

    • Sole Android developer of the Smooz mobile browser. Migrated it from Java to Kotlin and set it up so part-time developers could take it over.

    Result 100,000 downloads, 4.5★ in three months

  5. 2013 — 2017

    Earlier roles

    Computec Japan · York University

    • Systems engineering, database administration and IT support in Tokyo. Web development and PL/SQL reporting for York University while studying.

How I work

AI tools changed how quickly I can build. They didn't change what makes software trustworthy: clear scope, review, tests and honest status updates.

  1. Prototype the risky part first

    I start with whatever could sink the project, usually the data model, the payment flow or the AI call. You get a clickable version within the first week or two. Demos beat specs.

  2. AI-assisted, not AI-unsupervised

    I work with coding agents such as Claude Code and Codex the way a lead works with a team. Every change has a written scope, a separate agent review and automated tests, and nothing merges without my sign-off.

  3. Product decisions in writing

    I ask who pays, what has to be true on day one, and what can wait. You get a short decision log, so the reasons behind a choice are still there in six months.

  4. Integrations that assume failure

    Stripe, payout providers, email, AI APIs and cloud jobs all fail in their own ways. I treat every webhook as untrusted, make every write idempotent, and check external state before acting on it.

  5. Tests where the money is

    Automated tests cover the paths that move money or change data, and deploys are gated in CI. I would rather ship a smaller feature that works than a bigger one that needs a hotfix.

  6. A weekly written update

    What shipped, what's next and what I need from you, plus a demo link. I'm async-first from UTC+8 and keep a regular overlap window for calls.

Have something to build?

A useful first email includes

  • What you want to build or fix, in a few sentences
  • Who uses it and what "done" looks like for you
  • Your timeline and rough budget range
  • Links to anything that exists already: designs, repo, live site

I reply within one working day, Kuala Lumpur time.

Elsewhere