Mobile
Native iOS in SwiftUI and native Android in Jetpack Compose, plus Wear OS and Android kiosk firmware. Offline first when the network cannot be trusted.
I build the systemsbusinesses run on.
Point of sale, ERP, human resources, business intelligence and artificial intelligence, 21 products in production. Backend, web panel, native iOS and Android, designed and shipped by one engineer.
$whoami
William Mazza | Software Engineer
$cat ./focus
mobile | backend and data | artificial intelligence | security
$uptime
22 products in production | 7 brands running on them | 2020
$
21
products in production
7
brands running on them
7
interface languages
2020
shipping since
What I do
One engineer, the whole stack.
I design and build the backend, the web panel, the native apps and the data layer of the same product. Nothing is handed between three teams, and nothing here is a prototype: it is all in production and in daily use.
Backend and data
NestJS and Node.js in strict TypeScript, Prisma on PostgreSQL, Redis and BullMQ for queues, warehouses that turn separate systems into one truth.
Artificial intelligence
Demand forecasting, OCR pipelines on vision and language models, retrieval augmented assistants, multi provider so no single vendor holds the product.
Security
Permission declared on every route and verified in continuous integration, multi tenant isolation under end to end tests, secrets in a manager and databases without a public address.
Selected work
21 products, in production.
Eleven management systems for a multi brand hospitality group and ten business applications sold and supported through TechCorp.
K-POS
Multi company cloud point of sale for bars, restaurants and chains
- NestJS
- TypeScript
- Prisma
- PostgreSQL
- Redis
- 7
AtomicBI
Multi channel business intelligence for multi brand hospitality
- PostgreSQL
- Data warehouse
- Node.js
- TypeScript
- SwiftUI
- 2
Platform ONE
All in one multi tenant human resources for hospitality and retail
- Node.js
- TypeScript
- PostgreSQL
- React
- SwiftUI
- 2
SupplyONE
Cloud native ERP for food cost, inventory and HACCP
- Node.js
- TypeScript
- PostgreSQL
- Cloud Vision
- LLM OCR
- 1
InvestFood AI
Artificial intelligence for food and beverage
- Python
- Forecasting
- LLM multi provider
- RAG
- PostgreSQL
BiteOS
Loyalty, ordering, payments and kiosk under one operating system
- Node.js
- TypeScript
- Firebase
- PostgreSQL
- SwiftUI
- 2
AmministraPRO
Accounting, meetings and documents for property administrators
- TypeScript
- Node.js
- PostgreSQL
- React
EdilPlanner
Jobs, sites, crews and cost control for construction
- TypeScript
- Firebase
- React
Animiyo
Health, prevention and expenses for every animal
- SwiftUI
- Jetpack Compose
- Firebase
Integrations
The systems these products talk to.
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The properties I build and maintain.
Static builds with their own generator, self hosted fonts, consent gated third parties and a full hreflang set. Editing happens in the source, never in the published folder.
In service every day
The brands running on this software.
Next
Where to find me in 2026.
Past
Where I have been.
Black Hat Europe 2025
Black Hat Europe
Recognition
Awards and press.
Certifications
Six IBM professional certificates.
Let's talk about what you are building.
Write to me. I read everything and answer where I can be genuinely useful.
Write to me