Otávio – React, Typescript, Node.js

A comprehensive cryptocurrency prime dealer and trading platform that provides deep liquidity and advanced trading infrastructure to institutional and retail investors. My work heavily focuses on SFOX Connect, a Crypto-as-a-Service solution that functions as a powerful, white-label API engine. Connect allows enterprise clients to seamlessly integrate crypto buying, selling, and holding capabilities into their own applications without having to build or manage the complex underlying blockchain infrastructure. Recently, the platform has also expanded into crypto derivatives, requiring highly adaptable and scalable backend systems to support rapid product iteration.

• Spearheaded an API-first development approach for SFOX Connect, prioritizing a flawless developer experience for enterprise clients integrating our systems.
• Enforced the "principle of least surprise" by ensuring strict backward compatibility and highly predictable API behaviors.
• Maintained rigorous quality standards in a high-stakes financial environment by ensuring comprehensive automated test coverage for all new features and legacy modifications, enabling safe, zero-defect deployments to production.
• Championed a "refactor-first" methodology, cleaning up and organizing legacy code prior to building out new features.
• Designed and built a dynamic user-tiering and rating calculation system. This rules engine evaluates a complex set of user requirements and automatically assigns tiers that govern access to specific platform features and trading limits.
• Collaborate deeply with the product team to refine broad, high-level tickets into precise technical specifications.
• Act as the sole API engineer for a newly launched cryptocurrency derivatives trading product.

It's a web-based management platform that digitizes child registration, attendance, and other administrative processes for institutions serving vulnerable children, providing managers with data-driven insights for better resource allocation and care.

• Architected and developed the management system from scratch, acting as the sole engineer responsible for the full project lifecycle, from initial concept to deployment.
• Translated stakeholder needs into a product roadmap, conducting interviews and analysis to define a set of actionable, high-value features.
• Engineered a data visualization page with interactive dashboards and dynamic charts, enabling school managers to gain actionable insights into students' data.
• Designed and implemented a CI/CD pipeline with GitHub Actions to automate build, testing, and deployment of Dockerized applications to Azure App Service.

It's the e-commerce platform for a global publishing and education company, where customers can buy academic material. The project goal was to migrate its legacy SAP system to a modern, more flexible, and resilient architecture.

• Architected serverless workflows using AWS Lambda & Typescript, cutting operational costs 20%.
• Led decommission of Hybris SAP to modern NodeJS cloud architecture, delivering $40k/month savings.
• Produced technical documentation and API specs, boosting team autonomy and onboarding speed.
• Raised code coverage to 80%+ with robust unit and integration tests.
• Actively participated in design discussions and contributed to technical specifications.
• Investigated and resolved issues in the production environment using AWS CloudWatch and Grafana, maintaining the integrity of the system.

It's a scalable platform that automates the issuance of mandatory fiscal documents for the Brazilian logistics sector.

• Led development squad in architecture, code reviews, and tech selection, improving delivery velocity.
• Built a high-performance front-end in React and Next.js using hooks, memoization, and SWR, enhancing UX responsiveness.
• Engineered Redis caching, reducing DB load and API latency by 90%.
• Created a large-scale Node.js Streams module for XLSX reports — 70% less memory use and faster throughput.
• Developed scalable REST APIs and 3rd-party integrations for expanded platform functionality.
• Built an asynchronous job queue with BullMQ and Bluebird for high-volume background tasks.
• Enhanced long-term system health by implementing Clean Code and SOLID principles, leading to fewer bugs and easier feature development.
• Managed Azure infrastructure (serverless functions, queues, databases), enabling new feature delivery at scale.

It's a shipment tracking and logistics management platform for companies in the road freight sector.

• Engineered the core back end and APIs for the platform using Adonis.js, turning raw data into a single source of truth for the front-end pages.
• Developed automated reporting features by leveraging SQL to enable managers to move from day-to-day operations to strategic analysis.
• Architected and built the full-stack registration system using React, streamlining the onboarding process and ensuring the system was scalable.
• Engineered a suite of external APIs using Serverless functions, which opened the platform to third-party integrations and new business partnerships.