Skip to content
  • starting gustavOS ok
  • MAGU: 27 products · VESUVIA: 3 products · books published: 11
  • stack: Cloudflare Workers · Supabase · Firebase · Stripe · Web Crypto
  • based in São Paulo, Brazil · working remotely, UTC−3

I build products.
Not websites.

Authentication, recurring billing, business-rule engines, encryption, row-level database permissions. The part that decides whether the product exists at all. Mine runs in production under two brands: MAGU, which I founded, and VESUVIA, which I co-founded and where I answer for product.

See the brands Discuss a project
Own brands

Two brands, two purposes

No single product stands alone here, and that is deliberate. What matters is the house it lives in: one for products born from daily use, another for companies born from a contract.

MAGUMake Anything Geniously Unique

The craftsman's brand.

Useful free tools, apps that respect your privacy and a complete project-management software.

I founded MAGU to give a name and a method to what used to live scattered across a hub with login and subscription. Today it has a partner, a catalog and clients, and every new product I sign goes through it.

Meet MAGU The brand, inside out
27products in the catalogAcross four lines: Tools, Private, Business and Performance.
17free toolsNo sign-up. Most run entirely in the browser.
2foundersProduct and AI on one side, marketing and strategy on the other.
Open the catalog magu.ia.br/products →
3products in operationFinancial management, commission engine and an AI assistant, each with an active client.
B2BfocusOperations where business rules move money and mistakes are expensive.
1teamProduct, engineering and operations under one roof.
Meet VESUVIA vesuv.ia.br →
VESUVIATechnology · Automation · Venture Studio

Intelligence that transforms businesses.

A technology and automation venture studio. B2B products built with a team, a roadmap and a contract, for operations where precision is not a differentiator but a prerequisite.

I am co-founder and VP of Product: I answer for each product's thesis, its architecture and what goes in or stays out of the roadmap. If MAGU is the workshop, VESUVIA is the scale.

Meet VESUVIA
Case studies

Two projects told end to end

What was stuck, what was decided and what is running in production. A B2B SaaS and a neighbourhood e-commerce.

splitOS

B2B commission SaaS · in production since Aug 2026

  • Test-covered commission calculation engine
  • Row-level permissions in Postgres
  • From a single file to 22 modules
SupabaseCloudflarePostgres RLS
Read the case

Bendito Coco

Neighbourhood e-commerce with own-fleet delivery · Tatuapé, São Paulo

  • 78 products, 10 sections and delivery to 26 neighbourhoods
  • Catalogue at the edge, cart in the browser
  • Guest checkout and a club with the member price up front
Next.jsCloudflare
Read the case
Capabilities

What I can do, proven by code that's live

Grouped by the problem it solves, not by framework name.

Billing that actually closes the month

Checkout, subscription webhooks, cancellation, reactivation and a credit wallet with atomic server-side debiting. Users can't grant themselves free credit.

StripeWorkersWebhooks

Business rules that move money

A calculation engine isolated from the interface, with unit tests running on every change. When someone's payout depends on the code, testing isn't optional.

NodeCIUnit tests

Real permissions, in the database

Row Level Security on Postgres and security rules on Realtime Database. Who sees what is decided on the server, not hidden in the UI.

SupabasePostgres RLSFirebase

Encryption in the browser

Notes, files and messages encrypted with AES-256 before leaving the device, with time-based self-destruction. No server ever sees the contents.

Web CryptoAES-256IndexedDB

Real time and peer to peer

Encrypted chat over WebRTC with no message server, plus ephemeral rooms that delete themselves. A direct connection between two browsers.

WebRTCRealtime DB

Processing without upload

Image compression, OCR and transcription running in the browser itself or behind an authenticated proxy. Privacy by architecture, not by promise.

CanvasTesseractWhisper

Dashboards people decide with

Sales funnel, lead scoring, weighted pipeline and monthly forecasting. Raw data turned into management decisions, not decorative charts.

DashboardsChartsXLSX

A front end that's safe and accessible

Per-route CSP, HSTS, isolation headers, visible keyboard focus, real contrast and reduced motion respected. No heavy framework where none is needed.

CSPWCAGDesign tokens
How I work

Six steps, no surprises halfway

You know where the project stands on any given day.

Step 01

Scoping

One call to understand the business problem. I leave with the business rules written down, and what's out of scope.

Step 02

Fixed proposal

Price, timeline and deliverables in writing. No surprise overage.

Step 03

Foundation

Database, permissions, authentication and a staging environment. The boring part that prevents rework later.

Step 04

Weekly builds

A working link every week. You test and adjust while changing things is still cheap.

Step 05

Production

Domain, security headers, monitoring and documentation of how everything works.

Step 06

Handover

You own the code, the accounts and the access. Nothing locked to me.

Packages

Where I usually come in

Starting figures. The final number comes after scoping.

Technical audit

For teams already in production

fromUS$ 2,000

1 to 2 weeks

  • Security review and credential exposure
  • Database permissions and API surface
  • Technical SEO and performance
  • Findings prioritized by impact
Request a quote

Complete micro-SaaS

To ship a paid product from zero

fromUS$ 9,500

4 to 8 weeks

  • Sign-in, roles and password recovery
  • Subscriptions, checkout and webhooks
  • Usage credits or plan limits
  • Customer dashboard and admin area
  • Row-level database permissions
  • Deploy, domain and documentation
Request a quote

Business-rule engine

For anyone calculating money in a spreadsheet

fromUS$ 6,000

3 to 5 weeks

  • Rules elicited and documented with you
  • Isolated, fully tested engine
  • Import from your existing spreadsheet
  • Audit trail for every calculation
Request a quote

Hourly consulting

To unblock one specific decision

fromUS$ 135/h

On demand

  • Architecture and stack selection
  • Code and security review
  • Support for an in-house team
Request a quote

Need it sooner? The math is transparent

Custom work starts at US$ 950, priced by scope, with a standard 7-day turnaround. Shorter deadlines add an urgency premium on top of the base price:

7 days or moreBase
Within 5 days+25%
Within 3 days+50%
Within 24 hours+100%
By end of day+150%

Every request is assessed for feasibility before we commit. If the requested deadline isn't workable, the commitment is to deliver on the shortest one that is.

Quote a custom scope
Next step

Tell me the problem.
I'll tell you if I can solve it.

If it isn't my kind of work, I'll say so on the first call and point you to someone else. Nobody gains from a proposal that won't close.

Request a quote Book 30 minutes (in Portuguese)

Rather use email? [email protected]