Our own products, client builds and open-source work, from a 2021 neural-network image app to MCP servers for Claude. Each project says plainly whose it was.
2023–nowOur own product
An all-in-one workspace for service businesses: CRM, proposals, invoicing and payments, scheduling and a shared email, SMS and voice inbox. Designed, built and run by App369.
2022–2026Client project, Simon as lead developer
Contractor CRM, iOS, Android & web
A CRM for home service contractors: quotes, scheduling, invoices and payments, customer messaging and AI automations. Simon was lead developer from before its App Store launch in September 2022 until September 2026.
FlutterNuxtFirebaseStripeTwilio
2026Our own product
Music app
A private music app: search, a now-playing screen with background playback, a queue, playlists, liked songs, a cloud library and listening stats, in dark and light themes.
FlutterFirebaseTypeScriptjust_audioHive
2026Open source by Simon Dziak
AI integration
An MCP server that lets Claude use a SaaS API safely: every call is scoped to one user's workspace, writes need explicit confirmation, and the HTTP transport is rate limited.
TypeScriptMCPClaude
2026Open source by Simon Dziak
AI agents
A reference build for making a Claude tool-use agent dependable in production: loop caps, schema-enforced output, a durable retry queue, prompt caching and per-call tracing.
TypeScriptClaude API
2026Open source by Simon Dziak
Data pipeline
A polite crawler feeding a validated SQLite ETL with price history, published as a static dashboard and CSV export. Demonstrated on a public scraping sandbox.
TypeScriptSQLite
Client project
Mobile & web app
An app for finding, configuring and choosing BILSTEIN suspension products for a given vehicle, on mobile and the web.
MobileWeb
Client project
Mobile & web app
A data visualization dashboard, plus a mobile app for searching inventory.
MobileWebDashboards
Client store
Shopify store
A Polish health and wellness store for vitamins, supplements and natural remedies.
Shopify
Client store
Shopify store
A store for data cables and networking accessories.
Shopify
Client store
Shopify store
A store for urban bicycles and cycling accessories.
Shopify
Client store
Shopify store
A modern store for framed art at accessible prices.
Shopify
Client store
Shopify store
A health and wellness store for vitamins, supplements and natural remedies.
Shopify
Client store
Shopify store
A curated store for handcrafted fine jewelry, based in Canada.
Shopify
Concept work
Made-up brands we designed and built to show range. Not client work. Each one is live, so click through and try it on your phone.
Concept2026Concept site by App369, not a client project
Concept bakery website
A neighbourhood bakery in Coconut Grove. Live open or closed status on Miami time, today's bake list, pickup ordering with 15-minute slots and celebration cake pre-orders.
HTMLCSSJavaScript
Concept2026Concept site by App369, not a client project
Concept law firm website
An immigration firm in Brickell. Full English and Spanish, a three-question option finder, flat-fee ranges and consultation booking on Miami time.
HTMLCSSJavaScripti18n
Concept2026Concept site by App369, not a client project
Concept SaaS launch site
An AI phone receptionist for clinics and law firms. The hero plays a live call: waveform, typed transcript and an appointment landing in the calendar, plus a missed-calls calculator.
HTMLCSSCanvasJavaScript
Concept2026Concept site by App369, not a client project
Concept med spa website
A physician-led med spa in Miami. A treatment finder by concern and downtime with honest from prices, a full price list, and consultation booking with a chosen clinician on Miami time.
HTMLCSSJavaScript
Concept2026Concept site by App369, not a client project
Concept accounting firm website
A CPA firm for Miami small businesses, in English and Spanish. A monthly price builder for bookkeeping, payroll and returns, a 2026 federal and Florida tax-deadline calendar you can download, and call booking.
HTMLCSSJavaScripti18n
Concept2026Concept site by App369, not a client project
Concept dental practice website
A family dentist in Kendall, in English and Spanish. An insurance checker by carrier and plan type, a no-insurance membership plan with clear prices, and new-patient booking with evening and Saturday slots.
HTMLCSSJavaScripti18n
Concept2026Concept site by App369, not a client project
Concept restaurant website
A Cuban restaurant in Little Havana, in English and Spanish. The full menu as text with prices and dietary filters, reservations and takeout in one panel with pickup times that follow opening hours, and live open or closed status.
HTMLCSSJavaScripti18n
Concept2026Concept site by App369, not a client project
Concept product launch, WebGL
A Miami candle brand selling three scents. A real-time 3D candle in the hero changes scent and size as you choose, with a poster fallback for reduced motion and older devices, plus a working bag with a free-shipping meter.
HTMLCSSJavaScriptthree.jsWebGL
Concept2026Concept site by App369, not a client project
Concept roofing contractor website
A Miami-Dade roofer. A four-question ballpark price for tile, shingle, metal and flat roofs that leads into booking a free inspection, a service-area map, hurricane prep advice and a financing calculator.
HTMLCSSJavaScriptSVG
Tell us about your business and which concept is closest. Simon replies with a plan and a price.
Questions
Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.
Fixing, auditing or running something instead? See all fixed-price offers
