Saturno Mangieri Full-Stack Engineer
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Less talk. More working software.

Websites, platforms, mobile apps and AI assistants, designed and coded by one full-stack engineer. Open the live demos first. Then book a call.

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  • 6+years building software for web and mobile
  • 10,000+users on the product I worked on longest
  • $10,000+revenue from a single feature in 5 months
  • 2 monthsfrom idea to a working AI product
  • 290,000+lines of code committed to public repositories

Live demos and shipped work

Don't take my word for it. Open them, click around, try to break them.

Showing 8 of 8

SaaS platform, mobile-firstLive

RenovaYa

Problem
Businesses that bill monthly over WhatsApp lose track of who has paid and who is due.
Solution
One daily board for clients, due dates, payments and reminders, built for the phone first.
Result
Live today, in closed beta.

Role Design and development

Open live demo RenovaYa, opens in a new tab
Keychain swap widget

Mobile app + browser extensionIn production

Hive Keychain

Problem
People trust this crypto wallet with their funds, so every screen has to be clear.
Solution
As part of the team, I redesigned core screens and shipped 12+ features: among them a swap widget, and Android home-screen widgets written as native Java modules for the React Native app.
Result
10,000+ users. The swap widget generated $10,000+ in its first 5 months.

Role Engineer on the product team

View code Hive Keychain, opens in a new tab

A product in production. No public demo.

NaN Systems home page on desktop, dark theme

Website, blog and CVLive

NaN Systems

Problem
An engineering consultant in Austin, Texas needed one place for her services, portfolio, blog and CV, in English and Spanish.
Solution
A bilingual site with a blog she updates from a content manager, and light and dark themes.
Result
Live since 2020. Redesigned in 2026.

Role Design and development

Open live demo NaN Systems, opens in a new tab
Rocco Mangieri home page on desktop

WebsiteLive

Rocco Mangieri

Problem
A scholar needed his biography, publications and dossiers in one place, for readers in three languages.
Solution
An academic portfolio in English, Spanish and Italian, with downloadable dossiers and no trackers.
Result
Live today. One site, three languages, zero trackers.

Role Design and development

Open live demo Rocco Mangieri, opens in a new tab
JobABoard home page on desktop

Marketplace on the Hive blockchainBuilt in 2021

JobABoard

Problem
Let people publish jobs and services and get paid in cryptocurrency, wherever they work.
Solution
A marketplace on Hive: a Gatsby front end and a Node.js back end with MongoDB, its own image CDN and NFT tokens.
Result
Built end to end in 2021: 370+ commits between front end and back end.

Role Design and development

Open live demo JobABoard, opens in a new tabView code JobABoard, opens in a new tab

The front end is online. The back end runs on request: if you are interested in the NFTs on Hive, write to me ahead of time and I will switch it on for you to try.

The system in ten seconds: code filters, AI reads, a person confirms, the report comes out.

AI reporting platform for a US marketing agencyInternal client tool

AutoMastery

Problem
AutoMastery runs marketing for auto repair shops and reviews their phone calls. It needed client reports it could trust, straight from those calls.
Solution
Code sorts the calls, AI reads each one and quotes the exact words, code checks every quote against the transcript, and a person reviews only what is still in doubt.
Result
First working version in 2 months.

Role Design and development

Client website AutoMastery, opens in a new tab

An internal tool. No public demo.

Senda welcome screen

Mobile appNot released yet

Senda

Problem
Organisers of expeditions and guided experiences need to prepare each outing from their phone.
Solution
A control panel made for the phone: events with place, dates and a map, kept as drafts until they are ready to publish.
Result
Built. The client has not released it yet.

Role Design and development

Built for a client who has not released it yet.

Three services. Built properly.

From the first screen to the server behind it. One engineer, the whole stack.

Web Development

Sites and platforms that read clearly, load fast and connect to the tools your business already runs on.

  • Landing pages
  • B2B and B2C platforms
  • APIs and integrations

Mobile Apps

Custom apps for iOS and Android, for your customers or for your own team.

  • Custom iOS and Android apps
  • B2B and B2C
  • Native Android modules in Java for React Native

AI Assistants and Agents

AI assistants that I build and put into operation: as the front end your customers talk to, or as the back end that does the work. And full agents, installed and running on a server or on your own machines.

  • Assistants as front end
  • Assistants as back end
  • Full agents: OpenClaw, Hermes
  • On a VPS or on your own hardware

Also

  • Web3Wallets and crypto products.

How it works

One point of contact from the first call to delivery.

  1. You bring the need

    Tell me what the business needs. Plain words are enough. No technical brief required.

  2. Scope and price

    You get a clear scope and a price before any work starts.

  3. Build, delivered in parts

    Development with partial deliveries, so you see working software while it is being built.

  4. Delivery and support

    The finished product is handed over, with support after delivery.

Experience

Six years shipping products, on a team and on my own.

  1. 2026

    AutoMasteryDesign and development: AI reporting platform

    A platform that turns the phone calls of auto repair shops into client reports: AI reads each call, code checks every quote against the transcript and a person reviews what is still in doubt. First working version in 2 months.

    • Generative AI

  2. 2025 to today

    Independent engineer: products and client work

    AegisPad, RenovaYa, the Rocco Mangieri site and the NaN Systems redesign, plus open-source tools for the Hive blockchain.

    • Next.js
    • TypeScript
    • React
    • Node.js
    • Generative AI

  3. 2022 – 2024

    Hive KeychainEngineer on the product team

    Mobile app and browser extension of a crypto wallet with 10,000+ users. Redesigned core screens and shipped 12+ features, among them the swap widget and Android home-screen widgets in native Java. 1,500+ commits across both codebases.

    • React Native
    • React
    • TypeScript
    • Java (Android)

  4. 2021

    JobABoardDesign and development

    A marketplace for jobs and services paid in cryptocurrency on the Hive blockchain, front end and back end.

    • Gatsby
    • React
    • Node.js
    • MongoDB

  5. 2020 to today

    NaN SystemsDesign and development

    Bilingual site, blog and CV for an engineering consultant in Austin, Texas. Live since 2020, redesigned in 2026.

    • Gatsby
    • React
    • DatoCMS

One person designs it. The same person codes it.

Most software loses something between the design and the finished product. Here there is no handoff: how it looks and how it works are decided together, by one person accountable for both.

I am Saturno Mangieri, a senior full-stack engineer with 6+ years in React, Next.js, TypeScript, React Native and Node.js. For you, that means fewer meetings, faster answers and software that matches the plan.

Partners

Companies I build with.

  • In partnership with

    Financorp Consulting opens in a new tab

    A US consultancy that designs the financial, legal and strategic systems behind growing companies. When one of those systems is software, I build it: Financorp stays the client's point of contact, I design and code.

Stop patching. Start building.

Tell me what the business needs. I will tell you what it takes.

saturnob612@gmail.comBook a call