Studio Core
A shared framework and automated release pipeline behind 41 offline business apps, sold as one-time digital downloads.
- Own product line · Etsy digital downloads
- Founder & Product Engineer
- 2026 · Ongoing
- Proprietary / Internal
Overview
Studio Core is the framework behind a line of 41 offline management apps for small businesses and households: cleaning companies, pet groomers, gyms, restaurants, photographers, clinics, planners and more. Each app is a one-time purchase that opens with a double-click, works without internet, and keeps every record on the buyer's own device. Around it sits a Node.js pipeline that builds, tests, screenshots, documents and packages every product for sale.
The Problem
Small service businesses run on spreadsheets or pay monthly for SaaS they only half use. Most business templates sold online are Google Sheets or Notion files; very few are real apps. Building one polished app per industry by hand does not scale, and dozens of separately built apps drift apart in quality and look.
- ▸Buyers want real software (schedules, invoices, reports) without accounts, subscriptions, or their client list on someone else's server.
- ▸The app has to run from a local file, which rules out ES modules, web font files and any CDN.
- ▸Every product needs listing photos, a user guide and a download zip. Making those by hand for 41 products is weeks of work.
The Solution
I built one shared core that handles everything a business app needs: local storage, forms, tables, calendars, kanban boards, invoicing, charts, exports, backup and settings. A product only defines its own data, pages and one signature feature. Scripts then turn each product folder into a tested, documented, ready-to-sell download.
- ✓Define an entity once and get its form, detail drawer, searchable table, CSV import and delete-with-undo.
- ✓Quotes and invoices with line items, tax, discounts, part payments, and PDF output with the buyer's logo.
- ✓Installable PWA with a content-hashed service worker, so installed apps keep working offline.
- ✓Screenshots, 10 listing images and an 8-page PDF user guide generated for every product.
Architecture
Plain HTML, CSS and JavaScript with no build step on the buyer's side, and a Node.js toolchain on the seller's side.
Product Layer
Per-app config, data definitions, views, one signature feature, and seeded demo data with realistic names and dates relative to today.
Studio Core
Shared router, app shell, command palette, forms, tables, calendar, kanban, billing, expenses, charts and exports, copied into every product by the build script.
Local Data
IndexedDB through Dexie.js with an in-memory mirror so views read synchronously. JSON backup and restore, plus Excel, CSV and PDF export.
Release Pipeline
Node.js scripts with no npm dependencies drive headless Chrome over the DevTools protocol to run QA, capture screenshots, render listing images and print PDF guides, then zip each product.
Key Features
One Framework, 41 Products
Each product adds only its own data, pages and signature feature: a crew board for cleaners, a kennel board for boarding, a menu engineering matrix for restaurants, a client pipeline for photographers.
Offline From a Double-Click
Runs straight from index.html with every library and font bundled. No install, no account, no internet. Can also be installed as an app on desktop, tablet or phone.
Business-Grade Modules
Quotes and invoices, calendars with staff lanes, drag-and-drop boards, reports, Excel/CSV/PDF export, a Ctrl+K command palette, dark mode and a phone layout in every app.
Automated Release Pipeline
One command syncs the core and regenerates the service worker; others run QA, capture screenshots, render listing images, print user guides and build the download zip.
Technology Stack
Founder & Product Engineer
I own the product line end to end: market research, the shared framework, the release tooling and the Etsy listings.
- ▪Researched Etsy demand by niche and chose products where buyers already pay for spreadsheets but no strong app exists.
- ▪Designed and built Studio Core and its developer guide, the contract every product is built against.
- ▪Wrote the build, QA, screenshot, listing-image and user-guide scripts.
- ▪Directed AI coding agents building products in parallel, and set the definition of done every product must meet before it ships.
Product UI
Technical Challenges
Running From a Local File
Challenge: Browsers block ES modules and web font files on file:// pages, and buyers won't run a local server.
Solution: Classic scripts loaded in a fixed order under one global namespace, every library bundled in the zip, and the typeface inlined as a data URI. Installed as a PWA, a content-hashed service worker precaches every file.
Consistency Across 41 Products
Challenge: Many apps built in parallel drift apart in look, wording and quality.
Solution: Everything shared lives in Studio Core, which the build script copies into each product and overwrites on every build. A written design and copy guide sets the rules, and QA must pass with zero issues in light, dark and phone layouts.
Updating Apps People Already Use
Challenge: Buyers keep real business records in their browser, so an update that changes storage could wipe them.
Solution: Upgrades may not change database schemas, store names or keys, and may not remove working features. Every app has one-click JSON backup and restore, with a reminder when a backup is overdue.
Outcomes & Highlights
41 offline apps are packaged and ready to sell as digital downloads, each with its own listing photos and user guide. Adding a new industry now mostly means defining its data and its signature feature.
- ✓24 apps built on Studio Core, with the older apps being moved to the same standard.
- ✓A zero-dependency QA runner that checks every page of every app in light, dark and phone layouts.
- ✓Listing images, PDF guides and download zips generated by script, not by hand.
- ✓No backend, hosting costs or buyer accounts: data stays on the buyer's device.
- 41
- Apps shipped
- 0
- Servers or subscriptions
- 3
- QA passes per app
Each a ready-to-sell download
Data stays on the buyer's device
Light, dark and phone width
