João Netto.
I have been a software engineer for over ten years. I was a founding engineer on the Topps NFT platform, where I looked after payments and compliance while the business went from nothing to $2M a month. Most recently I was at ProveAI, building an LLM observability product for enterprise customers. I am now a senior software engineer at FCamara.
I like to understand how a system behaves before I pick the tool. When the stack is not already fixed by the requirements, I choose for the problem. I write Python, TypeScript and Elixir, and I follow what I write through to deployment.
I hold every piece of code to the same bar for readability and consistent patterns, agent-written included: it goes through the same review. I settle the architecture before the team starts, and then I build alongside them. Decisions get written down the day we make them, or the reasoning walks out with the people who were in the room.
01Experience
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Senior Software Engineer
Placed with Lojas Renner, owning the Caixa de Auto Atendimento, their in-store self-service platform. Second time at the company; the first was back in 2019.
- The frontend is React on Electron, running on the terminals inside the stores, and the BFF is Node.js with NestJS. I work on both ends.
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Senior Software Engineer
LLM observability platform for enterprise deployments, monitoring model quality. There are 11 of us, spread across the world.
- I built the Python SDK customers install to instrument their LLM applications and stream evaluation data into the platform.
- OpenTelemetry and Prometheus now run across 10+ customer deployments. TTFT, hallucination rate and toxicity rate all come out of that.
- I ran LLM-as-judge experiments to score response quality with no human reviewer in the loop.
- I rebuilt customer onboarding: static config became dynamic profiles with hot reload. Integration got 60% faster and started accepting hybrid infrastructure via Prometheus. Before that, any change of the sort meant restarting the containers.
- I made CI block the merge while the suite or the lint is failing. Coverage went from 30% to 75%, across the React/Vite frontend and the Node.js/Express backend.
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Senior Software Engineer
I built the Topps NFT platform at Popstand; team and client moved to Sortium when it was founded. I stayed on it for over 4 years, starting from the prototype.
Topps NFT Platform
- Founding engineer on a team of 3 fullstack and 5 frontend. I looked after the frontend, the Firebase/Cloud Functions BFF, the Node.js backend and the infrastructure. The platform held ~100K collectors, and drops pushed it to 10K concurrent users.
- I took on 5 payment gateway integrations: Checkout.com, Plaid, Wyre, Sardine and Fortress. They covered credit cards, digital wallets, ACH, wire and SWIFT on the fiat side, plus USD/USDT in crypto. At peak they moved $2M a month, half through primary drops, half through the marketplace.
- I led the migration from Checkout.com and Wyre to Fortress Trust and Sardine with no downtime, payments and KYC live throughout. Earlier I had built card fingerprinting and layered KYC, which cut fraudulent transactions by more than 95%.
- I looked after the Google Cloud layer for 5 years: Firestore realtime subscriptions, security rules, Cloud Functions as the BFF, Cloud Run services and Terraform-managed frontend infrastructure.
- I became the person people asked about the platform's business rules. I talked to the product side directly, drove the integration and architecture plans across sprints, and mentored 3 engineers on code quality.
- I was engineering's point of contact for the support team, working through the broken cases with them.
- I migrated 100,000+ NFTs to OpenSea and built an asset viewer that embedded straight into the marketplace.
AI Gateway (GenAI image generation)
- I helped build a multi-tenant API gateway in Python/FastAPI. It routes image-generation requests to internal GenAI services across 3 customer tiers, with a dedicated Celery queue per workload.
- I built the credit economy behind it: per-tier deduction, retries on worker failure, no charge for a generation that failed, and per-tenant usage feeding billing.
- Results come back over webhooks, and isolated Python workers handle post-processing.
- I led the refactor of a V1 that had shipped under launch pressure. I rebuilt the structure around FastAPI conventions: routing, business logic and integrations split into their own layers, explicit request and response models, dependency injection in place of imports, and the error handling and documentation it never had.
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Senior Software Engineer
Data tooling and realtime dashboards for credit analysis and sales.
- I built a React/Node.js ETL tool that mapped Excel documents (~1M records per file) into credit analysis and fraud detection APIs. It took 40 hours a month of manual work off the data team.
- I built a live sales dashboard (React + GraphQL + Apollo) spread across 8 TVs on the sales floor. A Redis cache layer unified reads over 7 databases and put an end to the table-level deadlocks that kept coming back.
02Earlier
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Senior Backend Developer
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Senior Backend Developer
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Mid-Level Backend Developer
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Mid-Level Frontend Developer
03Skills
04Education
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MBA, Software Architecture
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BSc, Systems Analysis and Development