🧠 Profile Summary
Hi, my name is Cesar Chavez.
I'm a Senior Java Developer, Full-Stack Developer, and Solution Architect with hands-on experience in DevOps and AI technologies. I also have some experience in QA automation.
I have more than 19 years of experience building enterprise applications across industries such as finance, automotive, cloud platforms, and online gaming.
Throughout my career, I have gained experience in full-stack Java development, cloud solutions, DevOps automation, and scalable software architecture. I have also held technical leadership and architecture roles in major international enterprises (TCS, USAA, BMW, Volvo, Credit Suisse, HP, HPE, ATOS/Worldline), consistently combining innovation, security, and performance optimization.
My technical background includes Java, Spring Boot, microservices, AWS, Terraform, Angular, React, Docker, Kubernetes, Node.js, C#, PHP, Python, and, more recently, AI technologies and large language model solutions.
🌍 Based in Wroclaw, Poland | Speaks Spanish 🇲🇽, English 🇬🇧, Polish 🇵🇱, Portuguese 🇧🇷
- 🎰 Senior Java Developer @ Playsmart — Spring Boot microservices for a multi-brand iGaming platform: bonus/rewards engine (cashback, wagering, free spins, missions), payment processing (Zimpler), game catalog & player lifecycle
- 🤖 Freelance Solution Architect @ Digitech Services — AI/LLM-powered apps with LangChain, Ollama, Hugging Face, TensorFlow & PyTorch
- ✅ AI Trainer / QA Coder @ BrainTrust – Toloka — validating AI deliverables and crafting domain-specific prompts for safe, trustworthy AI systems
- 🧑🏫 Mentoring developers and leading architectural decisions
- 🕹️ Exploring game development with Unity and Unreal Engine
Languages & Frameworks
Java, C#, Scala, Python, JavaScript, TypeScript, Bash
Spring Boot, Spring Cloud, JPA, Hibernate, Angular, React, Next.js, Node.js, Grails
Cloud & DevOps
AWS (EC2, S3, RDS, CloudFront, ALB), Terraform, Ansible, Packer, Jenkins, GitHub Actions, Docker, Kubernetes
AI/ML & NLP
Keras, TensorFlow, PyTorch, Hugging Face Transformers, LangChain, Ollama
Databases
PostgreSQL, MySQL, Oracle, MariaDB, MongoDB, Redis, SQL Server
Messaging & Tools
Kafka, ActiveMQ, Elasticsearch, Liquibase, JHipster, Gradle, Maven, MapStruct, Lombok, Git
- ✅ Software Architect Training Program 📄 Certificate (PDF)
- ✅ Advanced Architecting on AWS 📄 Certificate (PDF)
- ✅ Architecting on AWS 📄 Certificate (PDF)
- ✅ AWS Academy Graduate – Cloud Architecting 📄 Badge
- ✅ Software Architecture Fundamentals — Understanding the Basics
- ✅ Software Architecture Fundamentals — Beyond the Basics
- ✅ Software Architecture Fundamentals — People Skills
- ✅ Software Architecture Fundamentals — Soft Skills
- ✅ Java Memory Management
🎰 Playsmart – Senior Java Developer (Oct 2025 – Present)
Multi-brand iGaming platform on Spring Boot microservices — building features as part of the development team across the bonus/rewards engine (cashback, wheel bonuses, free spins, mission progression, wagering enforcement), payment processing (Zimpler integration, deposit/withdrawal controls), game integration services and player lifecycle. MariaDB, Kafka, Redis, Liquibase, Docker; Next.js on the frontend.
☁️ Digitech Services – Freelance Solution Architect / AI Engineer (Aug 2022 – Present)
Freelance full-stack, cloud and AI work. VirtualAssistLab virtual assistant: LLM/NLP in Python with Keras, TensorFlow, PyTorch and Hugging Face Transformers, orchestrated and served with LangChain and Ollama. Automation engineer on a large-scale web/mobile test-automation and CI project (Playwright, Appium, Sauce Labs, X-Ray, Allure) that improved coverage and sped up regression cycles; AI trainer/QA coder with BrainTrust–Toloka. Also Java, Node.js, Angular, React, Ionic, Scala, Terraform and AWS (EC2, S3, RDS).
🧩 BMW (via Reply) – Senior Java Developer (Dec 2022 – Sep 2023)
GWM Neu Wholesale and Guarantee modules: built and improved features, refactored the codebase for clarity and maintainability, and kept deployments smooth. Led the team through the fix of a critical certificate-issuance problem, hardened security with Spring JWT, SSO, SAML and OAuth2, and wrote support guides and scripts for specific issues. Java 11, Spring Boot, Oracle, AngularJS.
🏛️ ATOS / Worldline – Tech Lead / Solution Software Architect (Feb 2020 – Nov 2022)
Admiral: designed microservices, microfrontends and hexagonal architectures with a serverless deployment on AWS (ALB, CloudFront, S3), led architecture decisions and mentored developers. Forge Portal: led the development of high-throughput data-processing applications, designed multithreaded apps, and automated DevOps on AWS with Terraform, Ansible, Packer and Bash. Also UiPath RPA solutions and Spring JWT/SSO/SAML security; Java 11, Spring Boot, MySQL, JHipster, Angular 9.
🏎️ Volvo (via IT Kontrakt) – Senior Java Developer (Dec 2017 – Nov 2019)
Renault RT-DMS dealer management platform: planned and delivered new features and led its modernization — upgrade to the latest Java, refactoring of the legacy codebase for maintainability and performance, and the SVN→Git and Oracle→PostgreSQL migrations. Java, Spring, Oracle, PostgreSQL, Angular 4.
💳 Credit Suisse (via NATEK) – Senior Java Developer (Jul 2017 – Oct 2017)
Core Engineering Integration components team: conceived, planned and delivered new features, and refactored existing components so they ran more smoothly, were ready for new features and worked well together. Java 8, Spring, Oracle, Groovy, Grails.
🖥️ HP / HPE / DXC (via Dextra Technologies) – Senior Java Developer / Tech Lead / Solution Software Architect (Oct 2013 – Jun 2017)
Tech lead on UseIT, a multithreaded platform integrated with other services via endpoints: mentored developers, led a high-speed data-processing app and made it 35% faster with better Java multithreading, and played a key role in the cloud migration and server scaling. Also secure login, Java/web-service and database performance tuning, and new automation web services. Java 8, Spring, SQL Server, Angular 4; Apache on Linux.
🌐 Tata Consultancy Services (TCS) – Java Developer (Sep 2011 – Oct 2013)
Clients USAA, Citi Bank and General Electric. Built and maintained USAA's Special Relationships web applications from requirements through design and testing (Struts, Spring ORM, Hibernate, design patterns), deployed on WebSphere; developed Citi Bank Teradata Reporters modules (JavaScript, JSP, AJAX); proposed and planned improvements for GE's GECap Touchless Ph4 project.
- 🎓 M.Sc. – Universidad Autónoma de Guadalajara
- 🎓 Master of Information Technology – Universidad Latino
- 🎓 B.Sc. in Computer Science – Universidad Latino
🧘 Yoga & Meditation | 🥋 BJJ / Muay Thai | 💃 Forró Dance Instructor | 🧩 Game Development & AI
Let's build something amazing together!