Senior Software Engineer · Full-Stack — React + Java

I build products that hold up under high volume.

Full-stack Senior Software Engineer with 6+ years building web and mobile products with React, Next.js, React Native and TypeScript — on a solid Java/Spring foundation. Today I lead frontend for Red Ventures’ solar energy vertical, driving a ~30% conversion uplift in Q1.

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JVJosé Vinícius
José Vinícius
Santos de Melo
Open to new opportunities
nowRed Ventures
experience6+ years
focusFull-stack · high volume
stackReact · Next · Java
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About

I’m José Vinícius — a full-stack Senior Software Engineer from Pernambuco, with 6+ years spanning the frontend of products that convert and the backend of systems that scale.

I’ve led frontend for Red Ventures’ solar energy vertical and built, at Livelo, a points → PIX platform that became one of the company’s largest products. That product sense rests on years of backend work in high-throughput fintech (Java/Spring, Kafka, Kubernetes), giving me a genuine full-stack view on architectural decisions.

Reliability isn’t a detail. It’s the feature.
/02
Experience
2024 – Present · San Francisco, CA (Remote)

Senior Software Engineer

Red Ventures · BairesDev

Leading frontend engineering for the solar energy vertical — React/Next.js + TypeScript conversion experiences, in partnership with Vistra, driving ~30% conversion uplift in Q1 and ~60% cumulative growth. Built a Storybook + Tailwind design system consumed by multiple teams and a GraphQL layer that cut API latency by ~90%.

ReactNext.jsTypeScriptStorybookGraphQLTailwind
2022 – 2024 · Remote, BR

Senior Software Engineer

Livelo

Built the points-to-PIX conversion platform — within months, one of Livelo’s largest products, redeeming millions of points monthly: bank integrations, a complex settlement workflow, balance management and payment batches. I also developed the PIX module in Livelo’s React Native app.

JavaPIXReact NativeIntegrationsBatch
2021 – 2022 · São Paulo, BR

Senior Software Engineer

PagSeguro · PagBank

Designed the interchange fee estimation and billing system, processing ~3–4 million records daily, with event-driven pipelines (Kafka, RabbitMQ, Spring Cloud) on Kubernetes. Also delivered internal Angular and Next.js modules for offer configuration and fee management.

JavaSpring CloudKafkaAngularNext.jsKubernetes
2021 · concurrent · Remote

Technical Writer

Baeldung

Authored Spring Boot articles for a global developer audience, translating complex backend engineering concepts into actionable technical guidance.

Spring BootTechnical Writing
2021 · Brasília, BR

Senior Mobile Developer

Ília

Delivered React Native features inside Banco do Brasil’s Social Security app — serving ~2.5M users — working across mobile UI, API integration and release constraints in a high-visibility banking environment.

React NativeMobile UIBanco do Brasil
2019 – 2021 · Recife, BR

Software Developer → Senior Software Engineer

Flexpag

Built a payment checkout platform deployed across major Brazilian utilities (Celpe, Compesa, Cosern, Enel), enabling continuous billing during COVID-19. Promoted from Junior to Senior in under 2 years. Engineered a metrics platform that evolved from weekly manual reports to daily — and later real-time — reporting.

JavaPaymentsReporting
2016 – 2023 · Education

B.Sc. in Economics

UFPE — Federal University of Pernambuco

A quantitative grounding in economics, statistics and modeling — a different lens on financial-systems problems.

Full history on LinkedIn
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Featured projects

FeaturedRed Ventures · Customer Acquisition

Solar Energy Acquisition Flow

Grid/Cart — the React/Next.js acquisition flow that connects customers to major solar energy operators. Built around conversion, performance and a design system, driving a ~30% conversion uplift in Q1.

Next.jsReactTypeScriptCRO
FeaturedLivelo

Points → PIX

A platform that converts Livelo points into PIX — within months, one of Livelo’s largest products, redeeming millions of points monthly. I architected bank integrations, a complex settlement workflow, balance management and payment batches. I also worked on the PIX module in Livelo’s React Native app.

JavaPIXReact NativeBatch
Monthly redemption
Millions of points
PagSeguro · PagBank~3–4M/dia

Real-time Interchange+ Calculator

Real-time calculation of card-brand interchange fees (Mastercard, Visa, Elo), built on event pipelines processing ~3–4 million records daily.

JavaSpring CloudKafka
Dcifre

Open Finance Accounting Platform

An Open Finance platform for Dcifre (accounting), centralizing and controlling its clients’ many bank accounts.

Open FinanceAPIsBackend
Dcifre · Bacen

Bacen Resolution 4.966 compliance

Adapting accounting criteria to the new rules of Bacen Resolution 4.966/2021, adjusting the treatment and classification of financial instruments in the platform.

Accounting criteriaComplianceBackend
Flexpag · Celpe2020

Payment Totems & Online Checkout

Co-led Celpe’s payment totems and Flexpag’s online payment rollout during the pandemic, keeping billing alive for utility companies.

JavaPaymentsUtilities
Flexpag · CERC

Receivables · Resolution 264 (CERC)

Architecture of a system that calculated the receivables of the companies served (Flexpag was a sub-acquirer for Celpe, Cosern, Elektro and others), plus generating and sending the batches to CERC (the receivables registry), following financial-market infrastructure standards.

JavaReceivablesCERC
More on GitHub
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Skills

From the frontend that converts to the backend that scales — the stack I use end to end.

Frontend & Mobile
  • React · Next.js
  • React Native
  • TypeScript
  • Storybook
  • Tailwind CSS
  • Angular
Backend & APIs
  • Spring Boot
  • Spring Cloud
  • NestJS
  • GraphQL
  • REST · Express
Languages
  • TypeScript
  • JavaScript
  • Java
  • Python
  • Go
Data & Messaging
  • Apache Kafka
  • RabbitMQ
  • PostgreSQL
  • Oracle DB
  • Cassandra
Cloud & DevOps
  • Docker
  • Kubernetes
  • GitHub Actions
  • Jenkins
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Writing

Technical notes and essays, published on Medium.

Building a PIX Settlement Simulator with Java Virtual Threads

Modeling concurrency and payment settlement at scale on the JVM.

Jun 2026

Por que pássaros conseguem voar e humanos não?

An essay on freedom, limits and Brazilian neoliberalism.

Mar 2020
Read everything on Medium
/06 · Contact

Let’s build something.

Open to freelance, projects and new opportunities. Drop me a line — I reply fast.

josephdsbr@gmail.com
LinkedInGitHubMediumWhatsApp
© 2026 José Vinícius Santos de MeloCrafted with care · Pernambuco, BR