Illustrated avatar of Douglas Oliveira with curly hair, a beard and a black T-shirt

Hi, I'm

Douglas
Oliveira

I build APIs, interfaces and experiences with applied AI. Currently at Humana AI.

APIs, products and artificial intelligence

Full-stack
developer

About me

I'm a Full-Stack developer focused on back-end engineering and AI-powered products.

At Humana AI, I connect language models, agents and tools to web applications. I work from feature design to delivery, taking care of APIs, interfaces, data and tests.

My foundation combines Python, Node.js, React and TypeScript. Beyond coding, Ultimate Frisbee is my biggest passion.

São Paulo, BrazilSystems Development · FAM · 2024
Find me on LinkedIn

My career &
experience

Full-Stack Developer

Humana AI

2026 to
present
MAR 2026 — PRESENTBrazil · Remote

Building an AI platform, from designing features to delivering them in production.

  • Integrating LLMs, agents, tools, memory and streaming responses.
  • React/TypeScript interfaces, Node.js/Next.js APIs and PostgreSQL persistence with access controls.
  • Vitest and Playwright tests, CI and production support.

Full-Stack Developer

Appen Seguros

2025 to
2026
NOV 2025 — MAR 2026São Paulo · Hybrid

Automating billing and operational workflows with Python. Internal APIs with Node.js and AdonisJS, React and TypeScript applications, health insurance integrations and production support.

Full-Stack Developer

Freelance developer

2025MAY 2025 — NOV 2025São Paulo · Remote

Built a complete barbershop management system: scheduling, customers, services, financial management and SMS notifications. Developed, deployed and maintained the production application.

Before software development 2018–2025 View 3 earlier roles Hide earlier roles

Administrative assistant

Hospital e Maternidade Santa Joana

2021 to
2025
JAN 2021 — MAY 2025

Hospital administrative work, recording patient services and admissions in the SoulMV ERP. Followed up on requests to health insurance providers.

Hospital messenger

Pro Matre Paulista

2020 MAR 2020 — DEC 2020

Organized the department and maintained system records. Assisted with patient and document movement in the hospital's daily workflow.

Apprentice

Santa Rita Industrial e Comercial

2018 to
2019
JUN 2018 — JUN 2019

Organized and checked orders, supporting shipping routines. Worked across the order flow from preparation through dispatch.

Hands-on work at Humana AI

AI built
into the product.

My work connects models, agents and tools to the experience of the people using the application.

Let's talk about AI

Models & agents

Integrating multiple LLM providers, routing models and orchestrating agents with tool calling.

Tools & files

Controlled tool execution and isolated Python environments to generate documents and files from conversations.

Context & conversations

Chat streaming, contextual memory and persistent history, with permissions and data isolation across users and organizations.

Quality & reliability

Structured output validation, API contracts, error handling and automated tests for agents, interfaces and complete workflows.

An AI conversation needs to work as a product

At Humana AI, I contribute to flows that connect language models with the interface, tools and platform data. My work includes provider integration, streaming responses, conversation history and access controls. It comes together in persistent conversations, files generated from them, and interface and API tests.

Software engineering with AI

I work with different development tools and agents, choosing the approach to fit the problem. I combine specifications, context and validation to guide implementation and code review.

  • MCP and tool integration
  • RAG and knowledge retrieval
  • Model fine-tuning
  • Spec-Driven Development
  • Context and prompt engineering
  • Skills and development agents

Selected projects

Barbershop scheduling system

Client project · Full-Stack

Built for a real client: appointments, customers, services, finances and SMS notifications. From implementation to deployment and maintenance.

250
automated tests
CI/CD
GitHub Actions
Real
client in production
DjangoPythonPostgreSQLRailway

First API

Personal project · REST API

Asynchronous API with JWT authentication, user-isolated tasks, automated tests and an integrated interface. Containerized with Docker.

JWT
authentication
Async
FastAPI + SQLAlchemy
Docker
Compose
FastAPISQLAlchemyDockerPytest
Secret Number Game

Secret Number Game

Learning project · Interactive JavaScript

A number-guessing game with hints, an attempt counter and a restart option. Built with JavaScript, HTML and CSS.

Live
deployed on Vercel
JS
no frameworks
JavaScriptHTMLCSSVercel
Secret Santa draw interface

Secret Santa

Learning project · Logic & interface

An application to add participants and draw a Secret Santa, with name validation and a dynamically updated JavaScript interface.

Live
deployed on Vercel
JS
DOM & validation
JavaScriptHTMLCSS
01 / 04

My Technologies

Stack & tools

Back-end & data

  • Python
  • FastAPI
  • Django
  • Node.js
  • AdonisJS
  • PostgreSQL
  • MySQL

Web interfaces

  • React
  • Next.js
  • TypeScript
  • JavaScript
  • HTML5
  • CSS

Quality & delivery

  • Vitest
  • Playwright
  • Pytest
  • Docker
  • Git
  • GitHub Actions

Always learning

Education & certifications.

Higher education · 2022–2024

Systems Analysis and Development

Centro Universitário FAM

Completed a Brazilian undergraduate technology degree covering programming, databases and systems development.

Additional training

Oracle Next Education

Oracle + Alura

Java and AI development tracks, web projects, collaboration and self-management skills.

View certifications

Let's talk

Have an opportunity in Full-Stack development, back-end engineering or applied AI? Get in touch.

Douglas on the field with a medal and trophy from the Pindorama Ultimate Frisbee tournament
Ultimate Frisbee · Pindorama

Beyond the code

Ultimate Frisbee.
My passion on the field.

Brazilian Ultimate Frisbee champion

Ultimate Frisbee is my biggest passion outside technology. It is a team sport played with a flying disc, where players officiate their own games through dialogue, honesty and respect. This commitment to the spirit of the game is one of the things I love most about it.

I've been a Brazilian Ultimate Frisbee champion. That achievement means much more than a trophy: it reflects training, discipline, strategy and trust built with my team. On the field, I learned to communicate clearly, listen to different perspectives and take responsibility for my decisions — values I also bring to my work.

INSIDE THE PROJECT
View source on GitHub ↗