Marco Santana — Software Engineer

About

With over 25 years in software engineering, I have built a career spanning full-stack development, database architecture, cloud infrastructure, and technical leadership — from enterprise platforms at Microsoft Brazil to telemedicine systems, e-procurement SaaS, and AI-driven products at H2O.ai.

Today I work as an AI-native polyglot engineer — designing and shipping production software across TypeScript, Dart, Swift, and Rust with AI-assisted development as my core methodology. In the first quarter of 2026 alone, I shipped 800+ commits across 8 projects: a multi-tenant SaaS platform, a cross-platform music notation ecosystem (iPad + macOS App Store), a lunar-aware farm management app for iOS and Apple Watch, a privacy-first database app with Rust P2P sync, a community directory for a Brazilian coastal village, and a developer feedback SDK — all built with AI pair programming at every step.

I value pragmatic design, clean code, and work that makes a tangible difference.

Languages: Portuguese (native) · English (full professional) · Spanish (elementary)

Experience

Jan 2025 – Present Santa Catarina, Brazil

Designing, building, and shipping production software across five languages and multiple platforms — using AI-assisted development (Claude, ChatGPT, Grok) as a core engineering workflow. 800+ commits across 8 projects in Q1 2026.

Braxum — Multi-tenant SaaS with strong financial, SGA, and CRM modules. Next.js 16, TypeScript, PostgreSQL, Drizzle ORM. RBAC with 5 roles, TOTP 2FA, D3.js dashboards, 4-stage test pyramid, Terraform on AWS and GCP, Docker CI/CD.
Chordo — Music notation ecosystem with open-source libraries. Designed the ICLF specification for plain-text chord sheets. Parser library, music theory engine (key detection, voicing calculator, transposition), and cross-platform Flutter app shipped to iPad and macOS App Store. 4 repositories.
Moonstead — Lunar-aware farm management for iOS and Apple Watch. SwiftUI, HealthKit, CoreLocation. Real-time activity tracking with heart rate, GPS, cadence, and splits. Custom taxonomy with 250+ SF Symbols, aerial drone overlay, 4-language support.
Whisper DB — Privacy-first database app with P2P sync. Flutter frontend with Rust FFI backend. Ed25519 identity derivation, interactive diagram editor, 300+ tests.
Offline Studio — P2P sync framework in Rust. 10-crate workspace: HLC clocks, CRDTs, multi-transport networking, encrypted messaging, UniFFI bindings for Swift/iOS.
Alpha Tester — Embeddable feedback SDK for web apps. Turborepo monorepo, Next.js ingest API, Stripe-model API keys, rate limiting, CORS.
Ponta da Barra Info — Community directory for a Brazilian coastal village. Flutter Web on Cloudflare Pages. Offline-first with SQLite WASM, multilingual (PT/EN/ES).

TypeScript Dart Swift Rust Next.js Flutter SwiftUI PostgreSQL D3.js Terraform Docker GitHub Actions AWS GCP Cloudflare

Apr 2024 – Dec 2024

Focused period of study after four years at H2O.ai. Deepened expertise in AI engineering — LLMs, retrieval-augmented generation, prompt engineering, and AI-assisted development workflows. Began building the ICLF chord notation specification and early prototypes of the Chordo ecosystem.

May 2020 – Apr 2024 · 4 years Laguna, SC, Brazil

Built and maintained the user interface for H2O.ai's machine-learning platform in React and TypeScript. Developed shared component libraries, collaborated closely with design and backend teams, and contributed to internal developer tooling.

React TypeScript Storybook Fluent UI Go Buf.Build Adobe XD

Aug 2018 – Apr 2020 · 1 year 9 months Florianópolis, Brazil

Designed and implemented solutions for a North American e-procurement SaaS platform, progressing from senior engineer to team lead.

Technical Team Lead

Sep 2019 – Apr 2020

Led the team designing and implementing Dynamic Form Build Generation, WAND Taxonomy, and AWS Lambda/Gateway services. Onboarded new developers, provided day-to-day technical support to the team, and led grooming and planning meetings.

Senior Full Stack Engineer

Aug 2018 – Sep 2019

Designed and implemented solutions with Dynamic Form Build Generation, WAND Taxonomy, and AWS Lambda/Gateway services.

AWS Lambda API Gateway Node.js React

Mar 2018 – Sep 2018 · 7 months Florianópolis, Brazil

Built web applications for the civil engineering and construction industry.

Node.js MongoDB Angular

May 2015 – Mar 2018 · ~3 years Florianópolis, Brazil

Architected and developed a progressive web application for telemedicine. Managed multi-cloud infrastructure spanning IBM SoftLayer, AWS, Azure, and Google Cloud. Supported hiring and onboarding of technical staff.

ASP.NET Web API Entity Framework SQL Server AngularJS AWS Azure Google Cloud

May 2014 – May 2015 Laguna, Brazil

Co-founded and built a surf-related web platform from the ground up.

Node.js MongoDB PHP AWS NGINX

Oct 2014 – Feb 2015

Designed and built web solutions using WordPress, AWS, PHP, Node.js, and AngularJS.

Jan 2014 – Jun 2014

Migrated GIS features from Flash/ActionScript to JavaScript. Built Google Maps V3 integration for geospatial data visualization.

JavaScript Google Maps V3

Oct 2010 – Mar 2014

Freelance role focused on feature development, database performance optimization, and rewriting complex data routines.

Nov 2008 – Sep 2010 Florianópolis, Brazil

Led architecture and development of NFSe (electronic invoice) and time-clock systems. Mentored developers, conducted technical interviews, and served as interim engineering manager.

Jun 2007 – Oct 2008 Joinville, Brazil

Built a web-based GPS tracking system with real-time Google Maps integration for public transit monitoring.

ASP.NET SQL Server Google Maps

Apr 2008 – Jun 2008 Joinville, Brazil

Taught a 200-hour Microsoft .NET course covering C#, ASP.NET, and ORM fundamentals. Achieved 100% positive student feedback.

1998 – 2004 · 6 years São Paulo, Brazil

Six years at Microsoft spanning four roles, progressing from technical evangelism to innovation center management.

Innovation Center Program Manager

2002 – 2004

Selected and mentored top-performing students to build .NET applications. Managed innovation centers across six Brazilian cities: São Paulo, Rio de Janeiro, Curitiba, Porto Alegre, Recife, and Fortaleza.

Account Technical Specialist

2001 – 2002

Engaged with IT departments at assigned accounts, identified sales opportunities through technology assessment, and served as a liaison between support and technical teams.

Applications Engineer

1999 – 2001

Created training materials for the Microsoft Partners Channel. Supported line-of-business application development across enterprise verticals.

Seminar Group Member

1998 – 1999

Developed scenarios and delivered seminars on Microsoft technology nationwide.

Projects

Braxum

Multi-tenant SaaS platform with strong financial, SGA, and CRM modules. Full production system with role-based access control (5 roles), TOTP two-factor authentication, D3.js data visualization dashboards, drag-and-drop Kanban boards, vehicle inspection module with S3 uploads, and a 4-stage test pyramid. Dual-cloud Terraform infrastructure on AWS and GCP with Docker CI/CD.

Next.js 16 TypeScript PostgreSQL Drizzle D3.js Terraform Docker

Chordo

Cross-platform music notation ecosystem shipped to the iPad and macOS App Store. Renders ICLF chord sheets with syllable-precise alignment, features a dual-panel visual chord editor, voicing calculator, tag-based song organization, and instrument-aware rendering. Built on a custom music theory engine with key detection, Roman numeral analysis, and transposition.

Dart Flutter iPad macOS App Store

Moonstead

Lunar-aware farm management app for iOS and Apple Watch. Tracks real-time health and activity metrics — heart rate, GPS routes, cadence, pace, and splits. Features a custom taxonomy system with 250+ SF Symbols, aerial drone overlay for farm mapping, weather integration, and multilingual support in four languages.

Swift SwiftUI watchOS HealthKit CoreLocation GRDB

Whisper DB

Privacy-first database application with peer-to-peer sync. All data stays on-device with no cloud accounts required. Features an interactive diagram editor for visualizing table relationships, Ed25519 identity derivation, and a Rust FFI backend for cryptographic operations. 300+ unit and widget tests.

Flutter Rust FFI SQLite P2P

Offline Studio

Peer-to-peer synchronization framework built as a 10-crate Rust workspace. Implements Hybrid Logical Clocks, CRDTs, multi-transport networking, and encrypted messaging. Includes UniFFI bindings for Swift/iOS integration and a CLI with serve daemon for persistent channels.

Rust CRDTs P2P UniFFI Swift SDK

ICLF Standard

Inline Chorded Lyrics Format — an open plain-text specification for notating song lyrics with precisely positioned chords. Designed for human readability so musicians can open an .iclf file and play instantly. Supports syllable-precise chord alignment, extensible metadata directives, and accessibility for screen readers.

Specification CC BY 4.0

ICLF Parser

A Dart library that parses and validates ICLF files into structured data models. Classifies documents as valid, invalid, or recoverable — applying automatic corrections where possible. Includes a ChordMatcher for cross-ecosystem chord validation and a CLI for rendering chord sheets.

Dart Parsing CLI MIT

Music Theory

A Dart package and CLI providing programmatic access to music theory — notes, intervals, chords, instruments, voicing calculation, key detection, Roman numeral analysis, transposition, and capo suggestions. Serves as the theoretical foundation for the Chordo ecosystem.

Dart CLI Music Theory MIT

Ponta da Barra Info

Community directory for a coastal village in Laguna, SC, Brazil. Helps locals and tourists find service providers, transport schedules, and trails. Offline-first with bundled data, SQLite WASM for web, responsive hero carousel, and trilingual support (Portuguese, English, Spanish).

Flutter Cloudflare Pages SQLite WASM Multilingual

Skills

Languages

TypeScript Dart Swift Rust JavaScript C# / .NET Go SQL HTML / CSS

Frameworks & Platforms

Next.js React Flutter SwiftUI Node.js watchOS D3.js Drizzle ORM

AI & Development Methodology

AI-Assisted Development Claude LLM Integration Prompt Engineering RAG Pipelines

Cloud & Infrastructure

AWS Google Cloud Cloudflare Terraform Docker GitHub Actions Linux NGINX

Data & Databases

PostgreSQL SQLite SQL Server MongoDB Redis GRDB Data Modeling

Architecture & Practices

System Architecture API Design P2P / CRDTs Offline-First Multi-Tenancy Technical Leadership Test Pyramids

Recommendations

Marco is an exceptional professional with deep knowledge and remarkable technical command. He possesses the rare ability to convey complex ideas with clarity, making him an outstanding communicator and collaborator. His work is consistently of the highest quality, and his commitment to excellence is evident in everything he does. I wholeheartedly recommend Marco for any team looking for a talented, dedicated, and thoughtful engineer.

Claudio Fernando Maciel

CTO, Brokerme

I had the pleasure of working with Marco at Microsoft Brazil. He is a focused, hard-working professional with deep expertise across databases, web development, and software architecture. Marco is always eager to learn and share knowledge, and he brings a rare combination of technical skill and genuine teamwork. Any organization would benefit from his contributions.

Rob Ranches

BI Architect / Data Scientist, Bausch Health

Marco is an extraordinary professional with solid expertise in software development and architecture. He approaches every project with diligence, creativity, and a genuine desire to deliver the best possible solution. His ability to work across technologies and lead teams makes him an invaluable asset. I highly recommend him.

Jean Paulo da Silva Ramos

CEO, Ecovilas

Volunteer Work

SOS Gravatá

Creator, Developer & Maintainer

Oct 2013 – 2020

Environmental protection initiative that successfully defended coastal ecosystems and aquifer areas in the Gravatá region of Santa Catarina from unauthorized construction. Built and maintained the project's web presence, community outreach tools, and coordinated public awareness campaigns. The campaign achieved its goal — the construction was permanently stopped.

Sustainable Homesteading

Homesteader & Environmental Steward

2022 – Present · 4+ years

Four years of hands-on sustainable land management in the Atlantic Forest region of Santa Catarina. Practicing polyculture, permaculture, and agro-pasture-forest integration. Planting and nurturing native trees, caring for fruit and native sprouts with community donations, and active forest protection. Zero trees cut down, zero chemical inputs used. Learning and applying regenerative agriculture principles to restore and protect local biodiversity.

Education

FECAP — Fundação Escola de Comércio Álvares Penteado

Data Processing Technology

1993 – 1995

Certifications

Designing Desktop Applications with Microsoft Visual Basic 6.0

Exam 70-176

Designing Distributed Applications with Microsoft Visual Basic 6.0

Exam 70-175

Collaborative Solutions with MS Outlook 2000 / Exchange Server 5.5

Exam 70-105

About

Experience

Independent Software Engineer

AI Engineering / Studies

H2O.ai

BairesDev

Softplan

Portal Telemedicina

Guru das Ondas

Fresh Media

Geogrid Maps

Intersena

Cetil Sistemas

Imagem Tecnologia

SOCIESC

Microsoft Brasil