Open to opportunities · RemoteSão Paulo · BR— —:— —

MatheusSartori

Software engineer based in São Paulo. 9+ years designing architecture, code and products running in production for global companies — obsessed with performance, clarity and what matters to the end user.

02 · Impact

What I shipped
to production.

01since 2017
0+
Years building
Building production software since 2017 — from first internship to tech lead.
02auth / jwt
0K
Users authenticated daily
Across auth services I designed and still maintain — Best Buy, Surest, Qualcomm, FedEx, AARP.
03qa · playwright
0%
Fewer production defects
Playwright E2E framework I designed from scratch for LivePerson bots, adopted by the team.
04peak load
0K+
Simultaneous redemptions at peak
Children's Day cashback platform — 30K+ users redeemed without downtime, on autoscaling GCP.
03 · Brands shipped for

Companies that trusted
my code in production.

Retail2023 → 24
Best Buy
Node.js JWT service integrated with the mobile chatbot. Members enter authenticated without exposing the plans backend.
B
Health2023 → 24
Surest
Token with health-plan eligibility generated when the chat opens — auth and context in a single request.
S
Semiconductors2024
Qualcomm
Associate identity propagated from the corporate app into the conversational channel via JWT with custom claims.
Q
Logistics2024
FedEx
User session enters chat already authenticated, eliminating re-login and history loss in support.
F
Membership2024
AARP
Member auth with automatic token refresh and roles propagated to support in real time.
A
E-commerce2021 → 23
Mercado Libre
Regional platforms and activations for LATAM campaigns. Next.js front-end and Node back-end hosted on GCP.
M
FMCG2022
Ferrero
Children's Day cashback platform — 30K+ simultaneous redemptions on autoscaling GCP infra.
F
Beverages · AR2019 → 21
AB InBev
AR experiences on bottle labels with AR.js and Unity. The first delivery's success unlocked multiple contracts.
A
Pharma2022
Novo Nordisk
Digital platforms for internal campaigns and healthcare professional engagement — full stack with a compliance focus.
N
04 · Career

Building
systems since 2017.

2023 — Present

Senior Full Stack Engineer — Miratech

Designed a Playwright-based E2E framework for LivePerson bots, cutting production defects by 70%. Built the chatbot module of the mobile app in React Native, exposing the support channel to hundreds of thousands of members who had no prior access.

Developed the Node.js service that issues JWTs with health-plan eligibility — authenticating 100K+ users daily across integrations with Best Buy, Surest, Qualcomm, FedEx and AARP.

ReactNode.jsReact NativeTypeScriptDockerKafkaKubernetesJavaLivePerson
New York · Remote
Full-time
2024

Senior Full Stack Engineer — Progress Labs

Sole developer of a Next.js SaaS platform: users subscribe via Stripe and receive automatic web accessibility reports for the sites they register. Back-end on API routes, Cloud Tasks and Cloud Run; reporting directly to the IT director.

Next.jsNode.jsTypeScriptStripeGCPFirebaseAxe Puppeteer
New York · Remote
Part-time
2021 — 2023

Senior Engineer & Tech Lead — Mandarin Agency

Co-founded the agency's engineering department alongside the IT director: hired and mentored developers, established code review, git flow, scrum, test automation and CI/CD practices.

Led the delivery of a cashback platform for a multinational food company during Children's Day — 30K+ concurrent users redeemed cashback without downtime. Managed the full infrastructure on GCP and Vercel, optimizing cost via recurring allocation reviews.

Next.jsNode.jsTypeScriptMySQLGCPGraphQLLeadershipMentoring
São Paulo · Remote
Tech Lead
2021

Senior Full Stack Engineer — Rojemac

Solved recurring third-party ERP instability with a Next.js SSG fallback — result: +30% orders created per month. Established the company's testing culture with Jest and Supertest, reducing production regressions.

Next.jsNode.jsTypeScriptPostgreSQLGraphQLMongoDB
São Paulo · Hybrid
2018 — 2021

Full Stack Engineer — KASI

Designed AR experiences on bottle labels for one of the world's largest breweries with AR.js and Unity — the project's success unlocked multiple follow-up contracts. Built an award-winning glass-recycling ecosystem via reverse logistics in React Native and Node.js, responsible for 7000+ tons recycled to date.

ReactReact NativeNode.jsReduxMySQLUnityAWSAR.js
São Paulo · On-site
2017 — 2018

Full Stack Engineer — Betalabs

Built the bank-slip (boleto) processing module integrated with one of Brazil's largest banks, enabling a new checkout method across the entire e-commerce platform.

Node.jsReactJavaScriptMySQLPHP
São Paulo · On-site
2017

Intern Full Stack Engineer — Noatel

Started my career automating processes with React and Node.js: turning static pages into a CMS, automating newsletters and building internal tools that unlocked team productivity.

ReactNode.jsJavaScriptPHPMySQL
São Paulo · On-site
05 · Stack

The tools I'm
fluent in.

01

Languages

04 items
TypeScript
JavaScript
PHP
Java
02

Frontend

05 items
React
Next.js
Context API
Redux
React Native
03

Backend

05 items
Node.js
NestJS
GraphQL
Laravel
Apache Kafka
04

Data

03 items
PostgreSQL
MySQL
MongoDB
05

Cloud & DevOps

07 items
Linux
Git
Docker
GCP
AWS
GH Actions
Kubernetes
06

Testing & QA

04 items
Jest
Vitest
Playwright
Cypress
06 · Personal projects

Code I write
out of curiosity.

01/12
P
screenshot · portfolio-v2
012026

Portfolio · v2

This very site. Hand-built in vanilla HTML, CSS and JavaScript — with light/dark theme, interactive terminal and i18n.

FrontendIn production
HTML5CSS3JavaScriptSVG
Visit live ↗ GitHub
D
screenshot · devstack-cli
022025

devstack · cli

TypeScript CLI for quickly bootstrapping dev environments, with presets for Node, Next, NestJS and Docker.

CLIWIP
TypeScriptNode.jsOclifDocker
Live unavailable GitHub
K
screenshot · kafka-playground
032025

kafka · playground

Sandbox for experimenting with event-driven architectures on Apache Kafka — producers, consumers and saga patterns running locally in containers.

BackendWIP
TypeScriptNestJSApache KafkaDocker
Live unavailable GitHub
A
screenshot · a11y-watch
042024

a11y-watch

Web accessibility reporting SaaS. Users subscribe via Stripe and receive automatic audits of their registered sites.

Frontend · BackendArchived
Next.jsTypeScriptStripeFirebaseGoogle Cloud
Live unavailable GitHub
J
screenshot · jwt-claims-lab
052024

jwt-claims · lab

Lab for testing JWT propagation patterns, custom claims and automatic key rotation.

BackendWIP
Node.jsTypeScriptJWTRedis
Live unavailable GitHub
L
screenshot · lp-bot-runner
062024

lp-bot · runner

Local + CI runner for the LivePerson chatbot E2E tests I designed. Replays failures with recording and runs on every PR.

QA · CLIIn production
PlaywrightTypeScriptGitHub Actions
Live unavailable GitHub
G
screenshot · graphql-cookbook
072024

graphql · cookbook

Cookbook of GraphQL patterns — DataLoader, federation, persisted queries and how to avoid N+1 without thinking.

BackendWIP
GraphQLNestJSPostgreSQLApollo
Live unavailable GitHub
S
screenshot · sublink
082025

sublink

Link shortener with real-time analytics. Hono running on Cloudflare Workers + serverless Postgres.

BackendIn production
TypeScriptHonoCloudflarePostgreSQL
Visit live ↗ GitHub
$
screenshot · shellcraft
092025

shellcraft

Tiny Go CLI to manage shell aliases and keep them synced across machines via Gist.

CLIIn production
Go
Live unavailable GitHub
E
screenshot · next-on-edge
102025

next · on-edge

Comparative study of Next.js running on Cloudflare Workers vs Vercel — latency, cold start and cost.

FrontendWIP
Next.jsTypeScriptCloudflareVercel
Live unavailable GitHub
B
screenshot · boletos-go
112024

boletos · go

Go-based parser and reconciler for Brazilian bank slips (boletos) — a legacy from Betalabs, rewritten for performance.

BackendWIP
GoPostgreSQLDocker
Live unavailable GitHub
V
screenshot · arvc-labs
122023

arvc · labs

AR experiments on bottle labels — a personal extension of the work I did at KASI with breweries.

MobileArchived
React NativeJavaScriptUnityAR.js
Live unavailable GitHub
07 · Recommendations

What colleagues
say about working with me.

LinkedInAug 10, 2023

Working with Matheus is like having a tech-ninja master beside you! The guy is a true wizard with Node.js, React and everything else, in JavaScript or TypeScript. On top of that, he's a walking dictionary of creative, efficient, scalable and secure solutions — complete with docs and test coverage. His experience is honestly surreal: even when things get tangled, he untangles them with incredible clarity.

AS
Adriel Santana
Software Engineer · Tech Leader · AI/LLM · Co-Founder
Worked on the same team
01/25
auto
Want to verify? See on LinkedIn ↗
08 · Let's talk

Got a hard
problem? I'd love to hear.