Hi, I am
Gustavo Penido
Fullstack developer. From database to screen, infrastructure included.
The requirement says what. The conversation says why.
- 4255
- GitHub contributions in 12 months
- 111
- modules shipped across two systems
- 700+
- machines running an agent I wrote
- 4
- years with code in production
média móvel de 7 dias
How I work
I talk, then I write
I map the process with the people who run it and turn it into a written requirement before coding.
I build all of it
Database, API, screen and infrastructure. One person accountable for the whole.
I stay afterwards
I follow it in production, under real load and real incidents.
What I built
Service desk, ERP and RMM platform
It started by replacing a paid ticketing tool. Today it has 73 modules, handles contracts and billing, and remotely accesses 700+ machines.
- API modules
- 73API modules
- machines running the agent
- 700+machines running the agent
The company operating system
38 modules built single-handed, from first requirement to deploy. CRM, quoting, finance, chat, calendar, interviews and agile boards in one place.
- API modules
- 38API modules
- person from requirement to deploy
- 1person from requirement to deploy
Fleet routing engine
Weight, volume, stop limits and delivery windows solved by a solver, instead of a whole morning building loads by hand.
- checks before solving
- 5checks before solving
- routing providers integrated
- 2routing providers integrated
Government regulated e-invoicing
Four e-invoice types in a transport platform, with contingency for when the tax authority goes down mid-operation.
- fiscal document types
- 4fiscal document types
- documents lost to downtime
- 0documents lost to downtime
Control tower for cybersecurity
Different tools, different formats, different cadences. One screen, kept current on its own.
Bots and automation for a law office
Case lookup and registration straight from Discord, instead of someone opening the internal system and retyping everything.
Who you will be talking to
A well written requirement is half the work, and I take that seriously: I write epics, acceptance criteria and API contracts before opening the editor. But no document writes itself. It comes out of talking to the people who run the thing, otherwise you ship a flawless specification of the wrong problem.
I am a fullstack developer. I work from the database to the screen, and I look after what runs underneath. Before coding I write things down: epics, acceptance criteria, API contracts. And before writing them I talk to support, to operations, to the people who fight the system every day. That conversation is what makes a requirement worth having.
- Certification
- Foundations of Project ManagementGoogle · 2022
- Education
- BSc in Software EngineeringPUC Minas · in progressTechnical degree in ComputingCEFET-MG · completed
What I build with
Front
- TypeScript
- React
- Next.js
- Tailwind
Back
- Node.js
- NestJS
- PHP 8
- Laravel
- Python
- Rust
Data
- PostgreSQL
- Prisma
- MySQL
- MongoDB
- Redis
Infra
- Docker
- Swarm
- Traefik
- GitHub Actions
- Linux
Track record
- Sep 2025 — present
Development & support lead
Logistics & transport SaaS/TMS · B2B platform in production
- I lead the development and support team without leaving the code.
- I maintain the Docker Swarm infrastructure with Traefik and the CI/CD pipelines.
- I diagnose and fix production incidents: saturating queues, Redis memory blowing up, unindexed queries.
- I brought AI into the team workflow, with an internal manual and OpenAPI contracts written before implementation.
- Mar 2025 — Aug 2025
Fullstack developer
Logistics & transport SaaS/TMS
- I built logistics operations and billing modules, from API to screen.
- I implemented the government e-invoicing integration, with XML validation, offline contingency and rejection handling.
- I refactored legacy code and tuned queries on MongoDB and MySQL.
- Oct 2024 — Mar 2025
Back-end developer, internship
Logistics & transport SaaS/TMS
- I built REST APIs in PHP and Laravel with Git Flow, Scrum and Jira.
- I took over the fleet routing engine, in Laravel and Python.
- Aug 2024 — Oct 2024
Front-end developer, internship
Logistics & transport SaaS/TMS
- I built responsive interfaces in Next.js and TypeScript, wired to the APIs.
- Aug 2022 — Aug 2023
Researcher and fullstack developer
CEFET-MG · junior research fellowship
- I single-handedly built the platform used in the institution science olympiad.
Sectors
B2B logistics SaaS
Transport, billing and e-invoicing under Brazilian tax and transport regulation.
Cybersecurity consultancy
Control towers and dynamic data import from disparate tools.
Legal consultancy
Client pipeline and history centralised away from personal phones.
Accounting
Routines that depended on exporting from one system and importing into another.
Healthcare
Event scheduling and institutional presence, including sleep medicine.
Education
Registration and tracking platform for a science olympiad.
Need a team, not a person?
When a project is bigger than one head, it runs through GMPX Tech. Same engineering, company structure.
Contact
Tell me what is stuck.
If I am not the right person for your case, I will say so, and point you to who is.
- +55 31 99510-6573
- Based in
- Belo Horizonte, Brazil · UTC−3