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Available for remote rolesLATAM timezone, US overlap
Vitor Rafael

Frontend-heavy Fullstack Engineer building scalable web and mobile products.

I work across React, Next.js, React Native and Node.js - focusing on performance, architecture and shipping products that hold up in the real world.

View projectsDownload CV
Portfolio index

Systems I tend to improve

  1. 01Frontend architecture under real traffic
  2. 02Mobile products with native constraints
  3. 03Backend flows where retries and concurrency matter
vitorqfvitorqfrqfvitor@gmail.com
Impact

Built for scale, measured by outcomes.

A snapshot of the kind of problems I work on - high concurrency, large user bases and reliability under pressure.

3M+

Concurrent users simulated under load test

10+

WhatsApp groups automated for promotions

Selected work

Featured projects

A mix of frontend architecture, mobile engineering and backend reliability - chosen to show range, not volume.

Each case is framed by the engineering constraint, the system boundary, and the outcome it moved.

Case
01
Open Source / AI Engineering / 2026

ArchDrill

1 Case study

Open-source “LeetCode for system design”: problems with hard numeric constraints, a React Flow design canvas, a deterministic load simulator, and BYOK AI grading against hidden rubrics — all running in the browser with no backend.

Problem

Interview-quality feedback usually requires a server, accounts, and stored credentials — friction that kills a practice tool.

Outcome

A serious practice loop — design, simulate, break, get graded — with zero infrastructure and zero telemetry.

Case
02
Frontend Architecture / Performance / 2024

Tela Brasil

1 Case study

Public streaming platform focused on scalable delivery, playback reliability, and frontend performance under peak traffic.

Problem

SSR overloaded the limited frontend infrastructure at around 10,000 concurrent users.

Outcome

Scaled from around 10,000 to over 3 million concurrent users in load testing.

Case
03
SEO / Automation / Affiliate / 2023

Offertando

1 Case study

Built a deal aggregation platform with SEO-focused pages and WhatsApp automation for promotion distribution.

Problem

Promotion discovery needed search visibility and fast distribution across owned channels.

Outcome

A compact growth loop connecting SEO inventory with WhatsApp distribution.

Case
04
Mobile / Native SDK Integration / 2024

Safepilot

1 Case study

Led mobile development for a driving behavior app using React Native, Expo and native SDK integration.

Problem

The app needed native telemetry without making product screens depend on platform-specific details.

Outcome

Production-ready mobile application with native integrations and precise telemetry.

Capabilities

What I bring to a team

Grouped by where I tend to add the most leverage. Not a checklist - these are the areas I keep going deep on.

Frontend Architecture

Component systems, data layers and rendering strategies that scale beyond the demo.

  • Next.js
  • Tanstack
  • React
  • Typescript
  • Radix UI
  • Shadcn

Mobile Engineering

Cross-platform apps with native bridges where it matters: telemetry, sensors, deep OS integration.

  • React Native
  • Expo
  • Native Modules
  • Android
  • iOS
  • EAS

Backend Reliability

Concurrency, idempotency and consistency patterns for systems that can’t silently corrupt data.

  • Nest.js
  • Node.js
  • PostgreSQL
  • Redis
  • BullMQ
  • Prisma

Performance & CDN

Caching, edge delivery and client-side data strategies that take pressure off origin servers.

  • AWS CloudFront
  • Vercel
  • ISR
  • SSR
  • CSR

Product Thinking

Pragmatic scoping, user-facing tradeoffs and shipping the version that actually moves metrics.

  • Discovery
  • Prioritization

AI Engineering

Design and delivery of practical AI features using LLMs, retrieval pipelines, evaluation loops, and production-safe integration patterns.

  • OpenAI
  • OpenCode
  • LLM
  • Prompt Engineering
  • Vector Databases
Experience

Roles & impact

Senior frontend and fullstack roles delivering production software for high-traffic platforms and venture-backed startups.

  1. Nov/2024 - Present/Tela Brasil

    Frontend Engineer (Part-time)

    Public streaming platform (Tela Brasil) serving large-scale video content nationwide.

    • Migrated data layer to React Query improving performance and maintainability
    • Delivered system capable of supporting 3M+ users in load testing
    • Built video player supporting DASH and HLS streaming
    Next.jsTypescriptReactAWS CloudFront
  2. Nov/2024 - Present/Safepilot

    Mobile Lead - React Native Engineer (Part-time)

    I lead the React Native development of the SafePilot® app, a platform for analyzing driver behavior, focused on safety, efficiency, and responsibility in traffic.

    • Designed app architecture for production scale
    • Integrated proprietary telemetry SDK via native modules
    • Shipped to Android and iOS in a startup-style delivery cadence
    React NativeExpoNative ModulesAndroidiOSEAS
  3. 2021 - Present/Independent - Contract

    Fullstack Engineer (Freelance)

    Delivered web and mobile products end-to-end across affiliate and SaaS domains.

    • Shipped Offertando - SEO-driven affiliate platform with WhatsApp automation
    • Worked directly with founders on scoping and delivery
    Next.jsNest.jsPostgreSQLRedisAI EngineeringTDDDDD
Writing

Notes from production

Short, opinionated pieces on architecture decisions, concurrency, and what I have learned shipping software.

All writing
2 min read

Is Next.js always the right choice? Maybe not if you are strictly self-hosting.

The "Vercel Magic" is real: Vercel abstracts away massive complexity regarding Edge computing and CDN distribution. Replicating this manually on AWS is painful.

  • Next.js
  • React.js
  • AWS
  • Web Development
Read
2 min read

The best code won't save a product built in isolation 🏝️

As a Software Engineer, I’ve learned that my real contribution isn’t just in the lines of code I write, but in how I help the team make better decisions along the way.

  • Software Engineering
  • Web Development
  • Agile
  • Dev Life
Read
About

Pragmatic engineering, real-world products.

I am a software engineer from Brazil with strong frontend expertise and fullstack experience. I have worked on high-traffic web platforms, React Native apps with native SDK integrations, and systems where concurrency, idempotency and reliability matter. I care about pragmatic architecture, performance and building products that survive real-world usage.

Location
Based in Brazil
Timezone
LATAM timezone, US overlap
Languages
EN / PT-BR
Get in touch

Let us build something reliable, fast and useful.

Open to senior frontend, fullstack and mobile roles - full-time remote or contract. Comfortable working across LATAM, US and EU timezones.

Contact meDownload CVLinkedIn