Senior Backend Developer

Vinicius Koiti

Java Backend Engineer

Specialized in systems architecture, Event Sourcing, RAG, and multi-LLM integration. Java 21+, Spring Boot 3, Axon Framework.

Java 21+Spring Boot 3Axon FrameworkLangChainRAGEvent Sourcing
Maringá - PR, Brasil
viniciusnakahara@gmail.com+55 (44) 99747-9875
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Vinicius Koiti - Backend Developer
Open to new projects

Expertise Areas

Technical Specializations

Deep expertise in backend systems architecture, distributed computing, cloud infrastructure, and AI integration with enterprise-grade technologies.

Backend Development

Java 21 and Spring Boot 3 services in production — REST APIs, fiscal integrations and payment flows

Java 21+
Spring Boot 3
REST APIs
Microservices
SOLID Principles
Code Quality

Distributed Systems & Architecture

Event Sourcing/CQRS with Axon powering a financial commodities application

Event Sourcing
CQRS
Axon Framework
Saga Pattern
State Machines
Message Queues

Cloud & Infrastructure

CI/CD on Google Cloud (Cloud Build, App Engine) with zero-downtime deploys

Google Cloud
Docker
CI/CD Pipelines
Cloud Build · App Engine
AWS S3
Kubernetes

AI & LLM Integration

RAG with LangChain and PgVector — powering self-service that handles ~30% of support requests

RAG
LangChain
LLM Integration
Vector Databases
Hybrid Search
Prompt Engineering