Jefster Farlei

Jefster Farlei Fernandes Caixeta Júnior

Senior Backend Engineer | Java · Spring Boot · Golang · AI/LLM

Based in Goiânia, Brazil · Open to remote & global opportunities

Download CV Contact Me
1M+
Daily Transactions Handled
35%
System Throughput Improvement
10M+
Daily Transactions at Open Banking
9+
Years of Experience

About Me

Results-driven Software Engineer with 9+ years of experience designing and developing scalable backend solutions in Java (8-21), Spring Boot, and Golang. Skilled in RESTful & GraphQL APIs, microservices architecture, cloud computing (AWS, Azure), and database optimization (PostgreSQL, CosmosDB, Redis).

Adept at performance tuning, security, and high-availability architectures, with a track record of leading refactoring initiatives, mentoring developers, and optimizing distributed systems. Passionate about leveraging Golang for high-performance services and adopting cutting-edge technologies to drive business value.

Holds multiple industry-recognized certifications, including AWS Certified Solutions Architect Associate, AWS Cloud Practitioner, Microsoft Azure Fundamentals (AZ-900), and Azure Data Fundamentals (DP-900).

Technical Skills

Programming Languages & Frameworks

Java (8-21) Spring Boot Hibernate Golang Gin GORM Gorilla Mux Python NumPy Pandas Scikit-learn Flask FastAPI Node.js

AI / LLM & Data Science

LLMs RAG LangChain LangGraph PyTorch TensorFlow Prompt Engineering Machine Learning

Cloud & DevOps

AWS EC2 S3 RDS Azure CosmosDB Synapse DevOps Kubernetes Docker Terraform Jenkins GitHub Actions

Databases & Storage

PostgreSQL MySQL Redis SQL Server DynamoDB CosmosDB MongoDB Database Optimization

APIs, Messaging & Integration

REST GraphQL WebSockets OAuth2 JWT API Gateway Microservices Kafka Apache Reactor RabbitMQ Apache Camel Camunda

Monitoring, Security & Tools

Prometheus Grafana Kibana Azure Insights OWASP Top 10 Security Best Practices JMeter Java Flight Recorder Javers

Professional Experience

Software Engineer | Code17 Tek
Project: Tiger Analytics
06/2023 – Present

  • Led backend development team as a Tech Specialist, driving high-priority features, bug fixes, and product enhancements to meet business-critical deadlines.
  • Integrated backend services with React-based UIs, building end-to-end solutions for logistics and supply chain analytics, powered by machine learning models for demand forecasting, route optimization, and predictive operations.
  • Designed and optimized RESTful and GraphQL APIs, applying Domain-Driven Design (DDD), CQRS, and asynchronous processing with Kafka and Reactor, improving system throughput by 35% and enabling real-time data streaming across distributed services.
  • Developed high-performance APIs handling 1M+ daily transactions, integrating with CosmosDB, Redis, SQL Server, and Azure Synapse for scalable data storage and caching.
  • Enhanced system observability and performance monitoring, implementing Java Flight Recorder, JMeter, and Azure Insights, reducing debugging time.
  • Architected and deployed Golang-based APIs, leveraging Go's concurrency model and frameworks like Gorilla Mux, Gin, and GORM to build scalable, high-performance services.
  • Pioneered Proof-of-Concept (PoC) developments, evaluating new technologies like Go, Python, and Node.js, accelerating strategic decision-making.
  • Tech Stack: Java 17 & 21, Spring Boot, Tomcat, Spring Data, Spring Security, Hibernate, Javers, Maven, JWT, OAuth2, SSO, Azure Synapse, Cosmos DB, Azure Insights, AWS, SQL, PostgreSQL, Docker, OKTA, Terraform, GraphQL, WebSockets, REST, STOMP, Swagger, Redis, Golang, Gin, GORM, Gorilla Mux, Python, PyTorch, TensorFlow, FastAPI, Flask

Software Engineer | Novacomp
Project: Big Ticket Platform
05/2022 - 06/2023

  • Led the Notification Service project as technical lead, driving architecture decisions and delivery.
  • Integrated AI-powered notification systems with personalized content delivery using Python-based LLM solutions, increasing open rates by 45%.
  • Developed and optimized REST APIs, improving backend response time by 30%.
  • Designed and implemented a Kafka-based notification service, improving message delivery reliability by 99.9%.
  • Engineered efficient data models for customer information, reducing query execution times by 40%.
  • Tech Stack: Java 17, Spring Boot, Tomcat, OpenFeign, Spring Data, Hibernate, Maven, JWT, OAuth2, Auth0, Caffeine Cache, Swagger, Prometheus, Grafana, Loki, Vue.js, HTML, CSS, JavaScript, TypeScript, Pinia, Docker, Kubernetes, Jira, Git, GitHub, SQL, PostgreSQL, AWS, JUnit, Javers, Terraform

Software Engineer | Midway
Project: Open Banking Project
05/2021 - 05/2022

  • Designed and optimized API endpoints, improving data retrieval speeds by 40%.
  • Developed high-performance data models for customer and transactional data.
  • Ensured platform scalability, designing systems capable of handling 10M+ daily transactions.
  • Improved backend efficiency, reducing response times by 30% via API optimizations.
  • Tech Stack: Java 11, Spring Boot, Feign, Hibernate, OAuth2, JWT, OpenID, PostgreSQL, DynamoDB, AWS EC2, Azure DevOps, Docker, Kubernetes, SonarQube, JUnit, Apache Camel, Camunda

Software Engineer | Qintess
Project: Dell IoT
07/2020 – 05/2021

  • Strengthened application security, collaborating with the IoT security team to identify and mitigate vulnerabilities, reducing potential exploits by 40%.
  • Developed and deployed microservices for IoT and private cloud solutions, improving system scalability and reducing downtime by 30%.
  • Implemented secure coding practices, ensuring compliance with OWASP Top 10 standards, and reducing security incidents and vulnerabilities.
  • Optimized backend services, reducing API response times by 25% leveraging Spring Boot and RESTful APIs.
  • Tech Stack: Java 8 & 11, Spring Boot, REST, OAuth2, JWT, Hibernate, Swagger, Docker, Node.js, RabbitMQ, Redis, MongoDB, SonarQube, GitLab, Jenkins, Azure DevOps, Oracle Database, AngularJS, TypeScript, Camunda

Software Engineer | Indra
Project: Secretária de Estado e Saúde de Goiás
02/2019 – 07/2020

  • Developed critical health applications for the public health system of Goiás, Brazil (SES), enabling better medical logistics, disease monitoring, and surgical scheduling.
  • Designed and developed the SILT Application, enabling real-time tracking of Tuberculosis treatment and medication logistics, improving patient adherence and regulatory compliance.
  • Engineered the Svetores Application, integrating geolocation and mapping features to track insect species responsible for disease transmission, enhancing pest control strategies.
  • Developed the SisReg System, digitizing elective surgery scheduling based on Anvisa’s technical criteria, streamlining doctor requests, approvals, and procedure execution .
  • Managed public health medication distribution, ensuring accurate delivery and compliance with national health regulations .
  • Implemented automated work􀏐lows for handling infectious disease sample collection, ensuring proper safety protocols, and reducing manual effort in laboratory processing.
  • Led DevOps adoption, con􀏐iguring CI/CD pipelines with GitLab, Jenkins automation, and Flyway database migrations, improving deployment ef􀏐iciency and reducing manual errors.
  • Tech Stack: Java 8 & 11, Spring Boot, Tomcat, Node.js, Spring Data, Angular, TypeScript, Bootstrap,REST, SOAP, SQL, PostgreSQL, GitLab, Jenkins, Flyway

Full Stack Developer | WGL Solutions
Project: Ministério de Cidades
01/2018 – 02/2019

  • Designed and developed RESTful APIs, enabling seamless communication between applications and enhancing system interoperability.
  • Optimized REST clients to improve integration with legacy systems, reducing data transfer latency and processing bottlenecks.
  • Developed and maintained web applications for government and private sector projects, improving data accessibility and operational efficiency.
  • Led geolocation system enhancements, implementing building inspection and management features for federal agencies, and improving infrastructure tracking accuracy.
  • Enhanced the SisFogo system, optimizing heat map performance for geospatial visualizations, reducing data rendering time, and improving real-time analytical insights.
  • Refactored API endpoints, ensuring efficient data flow and seamless integration with government platforms, increasing system reliability.
  • Implemented unit and integration tests, improving code quality, scalability, and long-term maintainability.
  • Collaborated with cross-functional teams (front-end developers, data engineers, security experts) to develop scalable and secure solutions, improving system robustness.
  • Tech Stack: Java 8, Spring Boot, Tomcat, Swagger, Spring Data, Spring Security, Maven, JWT, Angular 6, HTML, CSS, JavaScript, AngularJS, AWS, PrimeNG, Hibernate, SQL, PostgreSQL, Liquibase, Spring REST Template, Git, OpenLayers, OpenStreetMap, PostGIS, OAuth2, JBoss Web Server, Apache POI, Apache HTTP Client

Full Stack Developer | Programar Informática
06/2016 – 12/2017

  • Developed and modernized ERP systems, migrating legacy software to modern web-based technologies, and improving functionality and performance for small business clients.
  • Designed fully responsive web applications, enhancing cross-device accessibility and improving user experience across multiple platforms.
  • Engineered an advanced task management system, streamlining internal workflow tracking and boosting operational efficiency for the company’s support team.
  • Designed and implemented a self-service totem, enabling independent customer purchases, reducing checkout time, and improving client satisfaction.
  • Developed and optimized logistics management solutions, improving inventory tracking, order processing, and supply chain efficiency for supermarkets, depots, and auto parts stores.
  • Collaborated closely with cross-functional teams, ensuring software solutions met business requirements and scalability standards, and adhered to tight project deadlines.
  • Tech Stack: Java 7, jQuery, Bootstrap, ExtJS, HTML, CSS, JavaScript, MySQL, SVN, Ant, iReport, ChartJS

Education

Graduate Certificate in Applied Mathematics and Statistics

UniAnhanguera, 2025

Advanced studies in mathematical modeling and statistical analysis for data science applications.

MBA in Project Management with Agile Methodologies

UniAnhanguera, 2024

Focused on implementing agile practices and effective project management techniques in software development.

Graduate Certificate in Solutions Architecture

PUC Minas, 2022

Specialized in designing robust, scalable, and efficient software architectures with focus on microservices and cloud-native applications.

Associate Degree in Software Analysis and Development

Maurício Nassau University, 2020

Foundation in software engineering principles, data structures, algorithms, and full-stack development.

Languages

Portuguese
Native
English
Professional Working Proficiency

Certifications

AWS Certified Solutions Architect Associate Badge

AWS Certified Solutions Architect Associate

AWS · 2023
AWS Cloud Practitioner Badge

AWS Cloud Practitioner

AWS · 2022
AZ-900 Badge

AZ-900

Azure Fundamentals - Microsoft · 2022
DP-900 Badge

DP-900

Azure Data Fundamentals - Microsoft · 2022
SFPC Badge

SFPC

Scrum Foundation Professional Certificate - CertiProf · 2024
DEPC Badge

DEPC

DevOps Essentials Professional Certificate - CertiProf · 2024
LFC108 Badge

LFC108

Cybersecurity Essentials - Linux Foundation · 2023
SKF100 Badge

SKF100

OWASP Top 10 Security Threats - Linux Foundation · 2023
LFC131 Badge

LFC131

Green Software for Practitioners - Linux Foundation · 2024

Contact Me

I'm currently open to new opportunities and collaborations. Open to: remote, hybrid, or on-site roles; full-time or contract engagements. Willing to relocate for the right opportunity. Feel free to reach out to me through any of the channels below:

jesterfarlei@gmail.com +55 62 99111-5292 LinkedIn GitHub

Send me a message