Let's build something useful
Backend Software Engineer
Hi, I'm João Gaino
Java, Spring Boot, NestJS, AWS
I build microservices, BFFs, serverless applications, and secure integrations for banking, marketplace, transport, and web platforms.
Focused on reliability, maintainable architecture, CI/CD, and practical AI-assisted engineering workflows.
About
Who I am
Hi, I'm Joao, a 25-year-old Backend Software Engineer based in Sao Paulo, Brazil, with 6+ years of experience building production systems for banking, marketplace, transport, and web platforms. I work mainly with Java, Spring Boot, NestJS, TypeScript, AWS, PostgreSQL, MongoDB, RabbitMQ, Docker, and CI/CD, with a strong focus on secure integrations, microservices, BFF architecture, and serverless applications.
I enjoy turning complex business workflows into reliable, maintainable software. In recent roles, I helped modernize AWS-based applications, build corporate banking post-sales flows, support high-scale marketplace services, reduce processing time by 30%, reduce manual effort by 40%, and improve authentication reliability. I also use AI-assisted development workflows with tools like Devin and Codex for codebase exploration, implementation planning, refactoring, documentation, and test generation while keeping engineering review ownership.
Experience
Where I've worked
1y 7mos
Itau Unibanco
Software Engineer
- Corporate banking, BFFs, and AWS:
- Develop BFFs with Spring Boot and Angular for contract renegotiation eligibility, simulation, and execution workflows.
- Modernize core applications on AWS using S3, EC2, Lambda, ECR, and API Gateway to improve scalability, reliability, and operational performance.
- Build secure integrations for high-scale financial transactions and corporate banking processes.
- Designed and implemented a new AWS serverless application from scratch, covering infrastructure, backend development, deployment, and scalability.
- Reduced processing time by 30% while improving service availability for business-critical workflows.
Java, Spring Boot, Angular, AWS S3, EC2, Lambda, ECR, API Gateway, Docker, CI/CD, Devin, Codex, Spec Driven Development
2y 3mos
Inmetrics
Software Engineer
- Marketplace microservices:
- Built Spring Boot microservices for Livelo marketplace domains including travel, flights, hotels, vehicles, orders, pricing, inventory, and product catalog.
- Developed services with MongoDB and RabbitMQ to support asynchronous processing, marketplace integrations, and high-scale request flows.
- Migrated legacy services and improved throughput, reliability, and failure handling across production workloads.
- Implemented data quality mechanisms to increase consistency across marketplace and order management processes.
- Reduced manual effort by 40% in customer order workflows and supported millions of monthly requests with higher efficiency.
Java, Spring Boot, NodeJS, NestJS, MongoDB, PostgreSQL, RabbitMQ, Redis, Docker, Microservices
1y 5mos
Eureka Labs
Junior Software Engineer
- ERP and SSO:
- Built an ERP system for a large transport company using NestJS, Prisma ORM, and backend services for operational workflows.
- Developed corporate Single Sign-On using JWT and authorization guards to centralize and secure authentication.
- Aligned authentication flows with enterprise security standards and reduced login-related issues by 50%.
ReactJS, NextJS, NodeJS, FeathersJS, NestJS, PrismaORM, PostgreSQL
10mos
SmarTI Inovacoes
Intern Software Engineer
Developed and maintained web pages using HTML, CSS, JavaScript, PHP, and MySQL.
HTML, CSS, JavaScript, PHP, MySQL, Visual Basic 6
Skills
What I can do
Java
Spring Boot
Spring Cloud
Spring Security
JUnit
Docker
Postgres
