Jefster Farlei

Jefster Farlei Fernandes Caixeta Jรบnior

Results-driven Software Engineer with 9+ years of experience

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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.

Recent focus on AI/LLM technologies, including developing RAG-based chatbots, fine-tuning models, and implementing AI-driven analytics solutions for business intelligence and process optimization.

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

Cloud & DevOps

  • AWS (EC2, S3, RDS)
  • Azure (CosmosDB, Synapse, DevOps)
  • Kubernetes, Docker, Terraform
  • CI/CD (Jenkins, GitHub Actions)

Databases & Storage

  • PostgreSQL, MySQL
  • Redis, SQL Server
  • DynamoDB, CosmosDB
  • Database optimization strategies

APIs & Protocols

  • REST, GraphQL
  • WebSockets, OAuth2, JWT
  • API Gateway, Microservices

AI & LLM Technologies

  • RAG Architectures
  • LLM Fine-tuning
  • Python ML/AI libraries (PyTorch, TensorFlow, spaCy)
  • Hugging Face Transformers, LangChain

Monitoring & Security

  • Prometheus, Grafana, Kibana
  • OWASP Top 10, Security best practices
  • Performance monitoring (JMeter, Flight Recorder)
รถ

Professional Experience

Software Engineer | Code17 Tek
Project: Tiger Analytics
06/2023 โ€“ Present

  • ๐—Ÿ๐—ฒ๐—ฑ ๐—ฏ๐—ฎ๐—ฐ๐—ธ๐—ฒ๐—ป๐—ฑ ๐—ฑ๐—ฒ๐˜ƒ๐—ฒ๐—น๐—ผ๐—ฝ๐—บ๐—ฒ๐—ป๐˜ ๐˜๐—ฒ๐—ฎ๐—บ ๐—ฎ๐˜€ ๐—ฎ ๐—ง๐—ฒ๐—ฐ๐—ต ๐—ฆ๐—ฝ๐—ฒ๐—ฐ๐—ถ๐—ฎ๐—น๐—ถ๐˜€๐˜, driving high-priority features, bug fixes, and product enhancements to meet business-critical deadlines.
  • ๐——๐—ฒ๐˜€๐—ถ๐—ด๐—ป๐—ฒ๐—ฑ ๐—ฎ๐—ป๐—ฑ ๐—ถ๐—บ๐—ฝ๐—น๐—ฒ๐—บ๐—ฒ๐—ป๐˜๐—ฒ๐—ฑ ๐—”๐—œ-๐—ฝ๐—ผ๐˜„๐—ฒ๐—ฟ๐—ฒ๐—ฑ ๐˜€๐˜‚๐—ฝ๐—ฝ๐—น๐˜† ๐—ฐ๐—ต๐—ฎ๐—ถ๐—ป ๐˜€๐—ผ๐—น๐˜‚๐˜๐—ถ๐—ผ๐—ป๐˜€, creating an intelligent chatbot leveraging Python and ๐—ฅ๐—ฒ๐˜๐—ฟ๐—ถ๐—ฒ๐˜ƒ๐—ฎ๐—น ๐—”๐˜‚๐—ด๐—บ๐—ฒ๐—ป๐˜๐—ฒ๐—ฑ ๐—š๐—ฒ๐—ป๐—ฒ๐—ฟ๐—ฎ๐˜๐—ถ๐—ผ๐—ป (๐—ฅ๐—”๐—š) to query real-time data on deliveries and shipping information, ๐—ถ๐—บ๐—ฝ๐—ฟ๐—ผ๐˜ƒ๐—ถ๐—ป๐—ด ๐—ฐ๐˜‚๐˜€๐˜๐—ผ๐—บ๐—ฒ๐—ฟ ๐˜€๐—ฒ๐—ฟ๐˜ƒ๐—ถ๐—ฐ๐—ฒ ๐—ฟ๐—ฒ๐˜€๐—ฝ๐—ผ๐—ป๐˜€๐—ฒ ๐˜๐—ถ๐—บ๐—ฒ๐˜€ ๐—ฏ๐˜† ๐Ÿฒ๐Ÿฑ%. Utilized PyTorch, LangChain, and FastAPI to build and deploy the solution.
  • ๐—ฆ๐—ฝ๐—ฒ๐—ฎ๐—ฟ๐—ต๐—ฒ๐—ฎ๐—ฑ๐—ฒ๐—ฑ ๐—Ÿ๐—Ÿ๐—  ๐—ณ๐—ถ๐—ป๐—ฒ-๐˜๐˜‚๐—ป๐—ถ๐—ป๐—ด ๐—ถ๐—ป๐—ถ๐˜๐—ถ๐—ฎ๐˜๐—ถ๐˜ƒ๐—ฒ๐˜€ ๐˜‚๐˜€๐—ถ๐—ป๐—ด ๐—ฃ๐˜†๐˜๐—ต๐—ผ๐—ป ๐— ๐—Ÿ ๐—ณ๐—ฟ๐—ฎ๐—บ๐—ฒ๐˜„๐—ผ๐—ฟ๐—ธ๐˜€, optimizing AI models for domain-specific terminology and supply chain processes. ๐—œ๐—บ๐—ฝ๐—น๐—ฒ๐—บ๐—ฒ๐—ป๐˜๐—ฒ๐—ฑ ๐—ฐ๐˜‚๐˜€๐˜๐—ผ๐—บ ๐˜๐—ฟ๐—ฎ๐—ถ๐—ป๐—ถ๐—ป๐—ด ๐—ฝ๐—ถ๐—ฝ๐—ฒ๐—น๐—ถ๐—ป๐—ฒ๐˜€ ๐˜„๐—ถ๐˜๐—ต ๐—ฃ๐˜†๐—ง๐—ผ๐—ฟ๐—ฐ๐—ต and ๐—›๐˜‚๐—ด๐—ด๐—ถ๐—ป๐—ด ๐—™๐—ฎ๐—ฐ๐—ฒ ๐—ง๐—ฟ๐—ฎ๐—ป๐˜€๐—ณ๐—ผ๐—ฟ๐—บ๐—ฒ๐—ฟ๐˜€, improving the accuracy of responses by 40% and reducing training time by 30%.
  • Implemented ๐—ฟ๐—ผ๐—ฏ๐˜‚๐˜€๐˜ ๐—”๐—œ ๐—ด๐˜‚๐—ฎ๐—ฟ๐—ฑ๐—ฟ๐—ฎ๐—ถ๐—น๐˜€ ๐—ฎ๐—ป๐—ฑ ๐˜€๐—ฎ๐—ณ๐—ฒ๐˜๐˜† ๐—บ๐—ฒ๐—ฐ๐—ต๐—ฎ๐—ป๐—ถ๐˜€๐—บ๐˜€, ensuring responsible AI deployment with proper data privacy compliance and ethical use of generative AI technologies.
  • ๐—œ๐—ป๐˜๐—ฒ๐—ด๐—ฟ๐—ฎ๐˜๐—ฒ๐—ฑ ๐—ฏ๐—ฎ๐—ฐ๐—ธ๐—ฒ๐—ป๐—ฑ ๐˜€๐—ฒ๐—ฟ๐˜ƒ๐—ถ๐—ฐ๐—ฒ๐˜€ ๐˜„๐—ถ๐˜๐—ต ๐—”๐—œ-๐—ฑ๐—ฟ๐—ถ๐˜ƒ๐—ฒ๐—ป ๐˜€๐—ผ๐—น๐˜‚๐˜๐—ถ๐—ผ๐—ป๐˜€ focused on logistics and supply chain data analytics, leveraging machine learning models for ๐—ฑ๐—ฒ๐—บ๐—ฎ๐—ป๐—ฑ ๐—ณ๐—ผ๐—ฟ๐—ฒ๐—ฐ๐—ฎ๐˜€๐˜๐—ถ๐—ป๐—ด, ๐—ฟ๐—ผ๐˜‚๐˜๐—ฒ ๐—ผ๐—ฝ๐˜๐—ถ๐—บ๐—ถ๐˜‡๐—ฎ๐˜๐—ถ๐—ผ๐—ป, ๐—ฎ๐—ป๐—ฑ ๐—ฝ๐—ฟ๐—ฒ๐—ฑ๐—ถ๐—ฐ๐˜๐—ถ๐˜ƒ๐—ฒ ๐—ผ๐—ฝ๐—ฒ๐—ฟ๐—ฎ๐˜๐—ถ๐—ผ๐—ป๐—ฎ๐—น ๐—ถ๐—ป๐˜€๐—ถ๐—ด๐—ต๐˜๐˜€.
  • ๐——๐—ฒ๐˜€๐—ถ๐—ด๐—ป๐—ฒ๐—ฑ ๐—ฎ๐—ป๐—ฑ ๐—ผ๐—ฝ๐˜๐—ถ๐—บ๐—ถ๐˜‡๐—ฒ๐—ฑ ๐—ฅ๐—˜๐—ฆ๐—ง & ๐—š๐—ฟ๐—ฎ๐—ฝ๐—ต๐—ค๐—Ÿ ๐—”๐—ฃ๐—œ๐˜€, improving system performance by 35% and ensuring seamless real-time data processing across multiple platforms.
  • Developed ๐—ต๐—ถ๐—ด๐—ต-๐—ฝ๐—ฒ๐—ฟ๐—ณ๐—ผ๐—ฟ๐—บ๐—ฎ๐—ป๐—ฐ๐—ฒ ๐—”๐—ฃ๐—œ๐˜€ ๐—ต๐—ฎ๐—ป๐—ฑ๐—น๐—ถ๐—ป๐—ด ๐Ÿญ ๐— + daily transactions, integrating with ๐—–๐—ผ๐˜€๐—บ๐—ผ๐˜€๐——๐—•, ๐—ฅ๐—ฒ๐—ฑ๐—ถ๐˜€, ๐—ฆ๐—ค๐—Ÿ ๐—ฆ๐—ฒ๐—ฟ๐˜ƒ๐—ฒ๐—ฟ, ๐—ฎ๐—ป๐—ฑ ๐—”๐˜‡๐˜‚๐—ฟ๐—ฒ ๐—ฆ๐˜†๐—ป๐—ฎ๐—ฝ๐˜€๐—ฒ for scalable data storage and caching.
  • ๐—˜๐—ป๐—ต๐—ฎ๐—ป๐—ฐ๐—ฒ๐—ฑ ๐˜€๐˜†๐˜€๐˜๐—ฒ๐—บ ๐—ผ๐—ฏ๐˜€๐—ฒ๐—ฟ๐˜ƒ๐—ฎ๐—ฏ๐—ถ๐—น๐—ถ๐˜๐˜† and performance monitoring, implementing Java Flight Recorder, JMeter, and Azure Insights, reducing debugging time.
  • ๐—”๐—ฟ๐—ฐ๐—ต๐—ถ๐˜๐—ฒ๐—ฐ๐˜๐—ฒ๐—ฑ ๐—ฎ๐—ป๐—ฑ ๐—ฑ๐—ฒ๐—ฝ๐—น๐—ผ๐˜†๐—ฒ๐—ฑ ๐—š๐—ผ๐—น๐—ฎ๐—ป๐—ด-๐—ฏ๐—ฎ๐˜€๐—ฒ๐—ฑ ๐—”๐—ฃ๐—œ๐˜€, leveraging Go's concurrency model and frameworks like Gorilla Mux, Gin, and GORM to build scalable, high-performance services.
  • ๐—ฃ๐—ถ๐—ผ๐—ป๐—ฒ๐—ฒ๐—ฟ๐—ฒ๐—ฑ ๐—ฃ๐—ฟ๐—ผ๐—ผ๐—ณ-๐—ผ๐—ณ-๐—–๐—ผ๐—ป๐—ฐ๐—ฒ๐—ฝ๐˜ (๐—ฃ๐—ผ๐—–) ๐—ฑ๐—ฒ๐˜ƒ๐—ฒ๐—น๐—ผ๐—ฝ๐—บ๐—ฒ๐—ป๐˜๐˜€, 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, NumPy, Pandas, spaCy, Hugging Face Transformers, LangChain, Azure Machine Learning, OpenAI APIs, LLM APIs, AI-based data analytics

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

  • Technical lead on the Notification Service project.
  • 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 โ€“ 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: Secretรกria de Estado e Saรบde de Goiรกs
02/2019 โ€“ 07/2020

  • Developed critical health applications for the public health system of Goiรกs, 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 Anvisaโ€™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 work๔€lows for handling infectious disease sample collection, ensuring proper safety protocols, and reducing manual effort in laboratory processing.
  • Led DevOps adoption, con๔€iguring CI/CD pipelines with GitLab, Jenkins automation, and Flyway database migrations, improving deployment ef๔€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: Ministรฉrio de Cidades
01/2018 โ€“ 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 Informรกtica
06/2016 โ€“ 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 companyโ€™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

Maurรญcio Nassau University, 2020

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

Certifications

AZ-900

Azure Fundamentals - Microsoft

DP-900

Azure Data Fundamentals - Microsoft

SFPC

Scrum Foundation Professional Certificate - CertiProf

DEPC

DevOps Essentials Professional Certificate - CertiProf

LFC108

Cybersecurity Essentials - Linux Foundation

SKF100

OWASP Top 10 Security Threats - Linux Foundation

LFC131

Green Software for Practitioners - Linux Foundation

Contact Me

I'm currently open to new opportunities and collaborations. Feel free to reach out to me through any of the channels below:

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