Nikola O.

Trafigura is one of the world’s largest physical commodities trading groups, operating globally across energy, metals, and renewables with enterprise-scale trading and data platforms.

• Supported the Front Office Data team by developing and maintaining backend services critical to trading and analytics workflows.

• Designed and implemented scalable Java-based microservices using Spring Boot, focusing on reliability, performance, and security.

• Integrated backend services with AWS infrastructure, ensuring stable deployments and high availability in production environments.

• Collaborated closely with data engineers, analysts, and frontend teams to deliver end-to-end solutions supporting trading operations.

• Contributed to production-grade systems handling high data volumes and strict performance requirements.

trefox is a digital agency delivering custom software solutions, including renewable energy tools and internal ERP platforms.

• Acted as a core developer on a request management tool for solar installation workflows.

• Built and maintained fullstack features using Node.js and React/Next.js.

• Contributed Java and Spring Boot expertise for backend services planned for a follow-up ERP project.

• Took ownership of architectural decisions and implementation details for critical application components.

• Worked independently in a small, fast-moving team, driving requirements and delivery forward.

The Sniffers is an industrial services company operating complex backend systems requiring high availability and strong DevOps practices.

• Developed and maintained Java Spring Boot backend services within a microservices architecture.

• Acted as a senior peer to the backend lead, contributing to design decisions and implementation quality.

• Managed dependency updates and ensured backend services remained secure and up to date.

• Supported CI/CD pipelines and deployment workflows across multiple environments (local, acceptance, production).

• Worked extensively with Docker and Kubernetes to maintain stable, containerized services.

• Built and maintained robust microservices using technologies such as Java with Spring Boot, Postgres, MongoDB, and others.
• Deployed microservices as Docker containers on cloud platforms like AWS and Azure.
• Contributed to the development of Node.js and Express microservices, ensuring seamless integration with React-based frontends.
• Collaborated closely with cross-functional teams to ensure smooth project delivery by addressing impediments affecting team effectiveness.
• Took on the role of DevOps champion and served as the dedicated person for DevOps-related tasks.

• Developed high-quality software solutions aimed at enhancing user experience and introducing innovative capabilities for ATM applications.
• Analyzed business needs and client requirements to design secure and efficient backend solutions using Java EE.
• Managed databases using SQL to ensure software reliability and performance.
• Utilized JavaScript and other technologies to create interactive and intuitive user interfaces.
• Participated in all stages of the development process, including analysis, design, implementation, and testing.

• Understood and analyzed requirements to develop effective solutions.
• Estimated project efforts and ensured timely delivery of features.
• Implemented new features and functionality using Java, Spring Boot, and other relevant technologies.
• Collaborated with colleagues to ensure code quality through code reviews and adherence to best practices.
• Followed version control practices using Git for efficient collaboration.
• Used JavaScript, HTML, and CSS to create intuitive and user-friendly interfaces.

• Worked on the implementation of a school inventory system using Meteor.js during the internship.
• Gained practical experience in full-stack web development through hands-on project work.
• Used JavaScript and Meteor.js to collaborate with the team in building an efficient and user-friendly system.
• Contributed to the development of key features for seamless tracking and management of school inventory items.
• Gained valuable insights into the software development lifecycle and agile methodologies.

Freelance