Senior Java Engineer

About The Opportunity

We are seeking a Software Engineer with experience in mission-critical systems to join an international project focused on automating and optimizing logistics and fulfillment processes. You will contribute to the evolution of a legacy core system – JESSI – used to manage the full shipment flow for international orders, from warehouse arrival to trailer dispatch. This system integrates with measurement devices, third-party vendors, and WMS platforms, and it displays real-time instructions to warehouse employees. It's a great opportunity for professionals eager to work in a highly technical environment involving monolith decomposition, microservices architecture, and real-time systems integration through messaging platforms such as Kafka and IBM MQ.

Responsibilities

• Develop, maintain, and enhance the mission-critical JESSI application, built using Spring Framework (not Spring Boot) and MyBatis/iBatis.
• Support the transition from a monolithic architecture to reusable microservices.
• Collaborate with integration teams to ensure seamless communication with external systems such as Warehouse Management System (WMS), Rate Selection, and Yardhouse Management.
• Improve the user interface used to provide operational guidance on large warehouse display screens.
• Ensure data flows accurately between automated measurement systems, the core application, and the end-user display.
• Manage the end-to-end labeling and carrier routing process, including data sent to shipping systems and end-of-day manifests.
• Participate in technical decisions and contribute ideas for improving scalability, performance, and resilience.

Required Qualifications

• Avaiablity to work on site, two days in the week. São Paulo or Belo Horizonte.
• Advanced/Fluent English.
• Strong experience with Java and Spring Framework
• Hands-on experience with MyBatis or iBatis.
• Solid background working with mission-critical systems and complex integration environments.
• Familiarity with messaging systems such as IBM MQ and/or Apache Kafka.
• Ability to work with and modernize legacy codebases

Nice To Have Skills

• Experience with microservices architecture and decomposition strategies.
• Knowledge of logistics, warehouse, or fulfillment systems.
• Experience building UI for operational environments (e.g., screen-based instructions for warehouse teams).
• Familiarity with automation systems or sensor-based data capture (e.g., automatic weighing and dimensioning).
• Experience working in environments with multiple stakeholders and legacy system dependencies.