Leonardo Balsalobre
Senior Software Engineer · AI-Powered Products with React, Node.js & LLMs · 10+ Years Full-Stack
Summary
Senior software engineer with 10+ years building production full-stack and AI-powered products. Specialized in React, Node.js, and TypeScript, with hands-on experience designing RAG pipelines, integrating LLMs, and shipping cloud-native systems on AWS. Frequently leads technical discussions, shapes product decisions, and mentors engineers to deliver reliable, maintainable software with measurable business impact.
Skills
React · React Native · Next.js · Node.js · Nest.js · TypeScript · JavaScript · GraphQL · REST APIs · AWS (ECS, EKS, Lambda, S3, DynamoDB) · Docker · Kubernetes · PostgreSQL · MongoDB · Redis · LLMs · Retrieval-Augmented Generation (RAG) · Prompt Engineering · AI-Assisted Development · System Design · CI/CD · Microservices · Clean Architecture
Experience
Senior Software Engineer — Balsa Tech
March 2025 – PresentRemote (United States)
- Deliver high-fidelity React and React Native products for global clients, accelerating roadmaps through AI-powered development orchestration.
- Integrate LLMs and AI tooling into the development lifecycle to boost delivery speed and code quality.
- Architect scalable frontend solutions with React, TypeScript, and Tailwind, paired with Node.js backends on AWS.
- Collaborate directly with international stakeholders to translate business needs into production-ready features.
Senior Software Engineer — Curebase
March 2024 – March 2025Remote (United States)
- Architected and implemented scalable features for a clinical-trial platform, ensuring regulatory compliance and system optimization.
- Managed release cycles end-to-end: CI/CD pipelines, testing strategies, and deployments.
- Stack: React, Material UI, Styled Components, Next.js, GraphQL, Node.js, Nest.js, Golang, AWS (ECS, EKS, DynamoDB, SQS, S3, RDS, CloudFront), Kubernetes, Docker, DataDog, GitHub Actions.
Lead Software Engineer — 2K Games
December 2023 – March 2024Remote (United States)
- Acted as tech lead for a cross-functional team building features used by 2K Games' global player base.
- Provided architectural guidance, set coding standards, and aligned engineering work with business goals.
- Facilitated sprint planning and reviews, led technical discussions, and mentored junior engineers.
- Drove the product roadmap with product owners and leadership while keeping code quality and performance on track.
Senior Full Stack Engineer — 2K Games
November 2022 – December 2023Remote (San Diego, CA, United States)
- Led development of the Portal Login Registration — 2K Games' centralized login platform serving players worldwide.
- Coordinated with regional teams across time zones to align requirements and delivery.
- Stack: React, Tailwind, Emotion, Contentful, Next.js, Node.js, GraphQL, Golang, Kubernetes.
- Streamlined development by introducing best practices and Clean Code principles, improving maintainability and onboarding speed.
Senior Full Stack Engineer — AWWCOR, Inc. (PatientFi)
November 2021 – December 2022Remote (Utah, United States)
- Contributed to PatientFi, a leading patient-financing platform used by healthcare providers nationwide.
- Implemented new features, improved existing functionality, and ensured cross-browser/device compatibility.
- Stack: React, Redux, Node.js, Express, Mongoose, MongoDB, TypeScript, AWS, Docker.
- Researched and applied frontend/backend best practices to raise the bar on performance, security, and UX.
Software Engineer — Itaú Unibanco
January 2021 – November 2021São Paulo, Brazil
- Built foundational components of a Banking-as-a-Service (BaaS) platform for the largest bank in Latin America, used by millions.
- Designed scalable, reliable infrastructure and established engineering best practices for future development.
- Stack: Kotlin, SpringBoot, NestJS, AWS (EKS, CloudFormation, Fargate, S3), DynamoDB, Kafka, jUnit, Jest, Swagger/OpenAPI.
Lead Software Engineer — New School
February 2020 – January 2021Brazil
- Led a team of 4 engineers building an application that delivers free quality education to youth from underserved communities.
- Owned the project end-to-end: infrastructure, architecture, delivery, and stakeholder communication.
- Stack: Vue.js, Vuetify, Nuxt.js, React, Next.js, React Native, Node.js, Nest.js, TypeORM, MySQL, Docker, AWS, Jest.
Software Engineer — Semantix Brasil (Unimed)
January 2019 – February 2020Brazil
- Led migration of Unimed Brazil's APIs to an API Gateway architecture, improving security and reliability of customer data flows.
- Built the Angular front-end used to manage the gateway's API surface.
- Stack: Node.js, Koa, MongoDB, Redis, Docker, Kubernetes, Angular, TypeScript, SCSS.
Software Engineer — Balsa Tech
January 2016 – December 2018Brazil
- Provided full-stack technology consulting to Infracommerce, Kobe Software, Nutax, Dasa, Nugget.ai, and Nearix.
- Designed and shipped tailored solutions, owning communication and delivery throughout each engagement.
- Stack: Vue.js, React, Redux, Node.js, Nest.js, MongoDB, PostgreSQL.
Education
MBA, Software Engineering
Bachelor's degree, Information Technology
Electrical and Electronics Engineering
Electrical, Electronic and Communications Engineering Technician
Certifications
JavaScript Algorithms and Data Structures · Microservices: Design Patterns · Go (Golang): Exploring Google's Programming Language · DataDog Foundation · Advanced JavaScript
Languages
Portuguese (Native) · English (Bilingual) · Spanish (Professional Working) · Italian (Elementary)
Honors & Awards
Developer who helped most