diniz.sh Email me

Backend engineer · São Paulo

I build the ways in. At Nexus I maintained every interface to the exchange, from the CLI and SDKs to the MCP server, and now I’m building the Nexus AI gateway and its web, desktop, mobile and CLI apps.

Email me See my work

Every way in.

A CLI, SDKs, an MCP server, and now a gateway. I’ve been writing backends since Share App and Cubos Academy, and lately most of what I build is a door: the way people and agents reach a system.

50×
faster biological data analysis, on a Google project. See the race
300k+
students and developers I was technical ambassador for at Cubos Academy
1st
place at the Rock New Ventures + IBM + HP hackathon, 2025
42 SP
cadet since 2025, learning peer to peer

2,364 contributions on GitHub in the last year

github.com/nvizble ↗
last 12 months · from GitHub

Experience.

Newest first. The first two have small demos further down the page.

  1. Nowat Nexus since Aug 2026

    Nexus

    Building the Nexus AI gateway and its apps

    One front door between a company and every model it uses: policies, budgets, an auto router that sends each step to the cheapest model that can do it, fallback across providers, linked plans and keys, and an audit log. I take part in the product decisions and develop its web, desktop, mobile and CLI apps.

    • Web app
    • Desktop app
    • Mobile app
    • CLI
    • Product
    • Auto router
    • Fallbacks
    • Budgets
    • Audit log
    See it route

  2. From Aug 2026

    Nexus

    Exchange interfaces: CLI, SDKs, MCP

    I maintained all the interfaces to the Nexus exchange: the CLI, the Rust, Go, TypeScript and Python SDKs, the MCP server for AI agents, and the rest. If you reached the exchange from a terminal, from code or from an agent, you went through something I maintained.

    • CLI
    • Rust SDK
    • Go SDK
    • TypeScript SDK
    • Python SDK
    • MCP server
    Try the order book

  3. Apr 2025 – 2026

    AC Digital

    Software Engineer

    I worked on a digital certificate issuance system built on PKCS #11, automated deployment pipelines with OKD, built custom reports in JasperReports, and kept the Java and Spring Boot legacy systems fast and reliable.

    • Java
    • Spring Boot
    • JPA
    • PKCS #11
    • OKD / OpenShift
    • JasperReports

  4. Oct 2024 – Jul 2025

    Creadev

    Software Engineer (contract), on a Google project for Servinformacion

    I led the architecture and stack choices for a large-scale RNA-seq analysis web app on Google Cloud, and drove the work that made its data analysis 50× faster. I also ran the feasibility analysis that shaped the approach, and defined the requirements with the stakeholders.

    • GCP
    • RNA-seq
    • Architecture
    • Performance
    Watch the 50×

  5. Aug 2023 – Dec 2024

    Share App

    Co-founder & Software Engineer

    I co-founded Share App and led its backend in Node.js and TypeScript: the databases, the cloud integrations, and mentoring the team. As a partner I also took part in the business decisions, until I sold my equity stake.

    • Node.js
    • TypeScript
    • Databases
    • Cloud integrations
    • Mentoring

  6. Jul 2024 – Dec 2024

    Cubos Academy

    Technical Ambassador

    I was a technical reference for a community of over 300,000 students and developers: I wrote technical articles and ran live coding sessions and workshops.

    • Articles
    • Live coding
    • Workshops
    • Mentoring

50× faster.

On a Google project, through Creadev, I led the architecture of a large-scale RNA-seq analysis app on Google Cloud and drove the performance work that made its biological data analysis 50 times faster. Here is what that ratio looks like on the same fifty samples.

Before: one sample done. After: all fifty, in the same time.

Every way into an exchange.

At Nexus I maintained all of the exchange’s interfaces: the CLI, every SDK, the MCP server for AI agents. Here is a small one running in your browser. Trade against it, then watch the same order go through every door.

Order book

DNZ/BRL · simulated

51.90depth, live52.70
52.30spread 0.01

Quantity 1 to 500. Price within 1.00 of the last trade.

Your fills, and how long the match took, show up here.

Trades

    Your orders

    • None resting.

    The same order, through every door

    Change the order and each interface rewrites itself: the command, the SDK call, or the agent’s tool call that would send it.

    $ exchange order place --market DNZ-BRL --side buy --price 52.30 --qty 25

    The Nexus AI gateway.

    At Nexus I build the AI gateway: one front door between a company and every model it uses. Each request is checked against its team’s policy and budget, sent to the cheapest model that can do the step, and moved to the next provider when one fails. I take part in the product decisions, and I develop the apps people use to reach it: web, desktop, mobile and the CLI.

    Take a provider down and watch its traffic fall back to the next one. apps I develop
    • Web
    • Desktop
    • Mobile
    • CLI
    • API
    Nexus

    In

    • Policyteam rules that only narrow as they go down
    • Budgeta cap per team

    Route

    • Auto routercheapest model that can do the step
    • Plans & keyslinked once, used everywhere
    • Fallbacknext provider in order

    Out

    • Audit logappend-only
    • Usagespend per team and model
    • Runsmanaged, or in your cloud

    Rust & Go.

    Two languages, two jobs, and two mascots that follow me everywhere.

    Rust

    For the hot path. No garbage collector pausing a request halfway through, and ownership rules that catch a data race at compile time instead of at three in the morning.

    $ cargo add tokio axum serde tracing

    Go

    For everything around it: services, tooling and glue the whole team can read on a Friday and ship on a Monday.

    $ go get google.golang.org/grpc

    Toolbox.

    The tools I reach for, and a hackathon I won with some of them.

    Key achievementWinner

    1st placeRock New Ventures + IBM + HP Hackathon, 2025

    A multimodal, generative-AI customer-service bot built with IBM Watson and RAG. It reads and interprets HP printer manuals, talks and listens through text-to-speech and speech-to-text, and runs natively on WhatsApp and Telegram. It won against several other teams.

    • Generative AI
    • RAG
    • IBM Watson
    • TTS/STT
    • WhatsApp
    • Telegram
    Languages
    • Go
    • Rust
    • TypeScript
    • Node.js
    • Python
    • Java
    • C

    Rust: certified through Alura.

    Frameworks
    • Spring Boot
    • Nest.js
    • JPA/Hibernate
    Data & messaging
    • PostgreSQL
    • Kafka
    • Redis
    • Google Cloud Pub/Sub
    Cloud & DevOps
    • GCP
    • AWS
    • Kubernetes
    • OKD/OpenShift
    • Docker
    • Terraform
    • CI/CD
    Architecture
    • Microservices
    • REST APIs
    • Distributed backends
    Security & PKI
    • PKCS #11
    • Digital certificates
    AI
    • Generative AI
    • RAG
    • IBM Watson
    • TTS/STT

    Learning.

    A peer-to-peer school, a degree in progress, and the courses that came first.

    1. 2025 – nowCadet

      42 São Paulo

      Intensive programming training, peer to peer: C, algorithms, operating systems, and hard practical projects.

      • C
      • Algorithms
      • Operating systems
      • Peer to peer

    2. 2024 – 2028B.S.

      FIAP

      Bachelor’s in Software Engineering at Faculdade de Informática e Administração Paulista.

    3. 2023 – 2024Course

      Cubos Academy

      Fullstack software development, and the backend and frontend certifications below.

    Certifications

    • Backend Programming from ScratchCubos Academy · Aug 2023 – Apr 2024
    • Frontend Software DevelopmentCubos Academy · May – Dec 2024
    • Rust: The Safe and Performant Programming LanguageAlura

    Building something people and agents call?

    joao@diniz.sh

    São Paulo, Brazil