LeonardoGoulart

senior full-stack engineer

I work on the parts of a product that need to be correct: the flows where a mistake has a real cost for the user, the API layer behind them, and the platform upgrades everyone keeps postponing.

./view_work ./hire_me

available · remote from Brazil

Selected work

001 · LIVE · SOLO BUILD

Readbinder

A reading tracker organized by concept instead of by book. Tag a passage as “karma”, and you can read what every author on your shelf said about the same idea.

constraint →: it has to work offline and feel fast
approach →: local-first on IndexedDB, Supabase only for sync
hard part →: resolving conflicts between devices

Next.js 16
TypeScript
Supabase
IndexedDB

Readbinder — concept graph linking every book on a shelf to shared ideas

002 · WORK · WRITE-UP
Fixing a two-year-old memory leak
ApolloClient instances weren't being garbage-collected in the Next.js SSR layer, and the problem had been there for two years. How I found it, how I migrated two repositories from Apollo v3 to v4, and how the memory graph looked after the fix.
STRIDE HEALTH · TENS OF THOUSANDS OF USERS
003 · OPEN SOURCE · CLI
Password Manager CLI
An encrypted local vault you use from the terminal: add, retrieve, remove. I built it to understand how the encryption actually works, instead of just using a library.
TYPESCRIPT · NODE.JS

What I work with

The tools I use, and what I've done with them.

frontend/
I've used both Next.js routers in production, and migrated a live enrollment flow from Page Router to App Router. The architecture diagrams I wrote are still the team's reference.
TypeScript · React · Next.jsTailwind · LaunchDarkly · Amplitude
backend/
I work with federated GraphQL: subgraphs on HIVE, Apollo on both the client and the server, and the caching decisions that keep a plan recommendation engine fast.
Node.js · GraphQL · ApolloREST · HIVE federation
infra/
The maintenance work that's easy to postpone: Nx v17 → v20 across repositories, ESLint flat config, and container deploys that don't surprise anyone.
Nx · Docker · AWS ECS / ECRCloudWatch · Parameter Store

Commit log

Software Engineer · Stride Health
2022.03 → HEAD · remote, US health-tech · team of ~5
I own the enrollment surface. I found an SSR memory leak that had been there for two years and fixed it by migrating two repositories from Apollo v3 to v4. It was affecting tens of thousands of active users.
- built the broker insurance flow end to end: recommendations engine, Medicare logic, on/off-exchange fork, shared restriction system
- migrated consumer enrollment from Page Router to App Router, and wrote the team's architecture diagrams
- upgraded Nx v17 → v20 across repositories, including ESLint v9 flat config
- onboarded three engineers with domain walkthroughs and pair programming
Fullstack Web Developer · Vórtx
2021.09 → 2022.03 · fintech, BR
Financial automation systems in React and Node. I improved an Azure ML model from 56% to 73% precision by cleaning and filtering its dataset, and built a reusable component library.
Fullstack Web Developer · Shift
2019.11 → 2021.09 · BR
Angular and TypeScript on an MVC codebase, REST APIs over Intersystems Caché, Docker deploys. This is where I learned to read an unfamiliar system before changing it.
2018 — initial commit · freelance design at Workana, while studying Computer Engineering