Senior Java Backend Architect - Payments Modernization

Citigroup Inc.; Mississauga; On-site; CAD 121,000 - 171,000; Full time

Job summary

Citigroup Inc. in Mississauga, Canada is seeking a Senior Java Backend Developer to join CitiDirect’s payments platform modernization. You will craft Java-based backend services, emphasizing Spring Framework, microservices, and secure APIs in a fast-paced financial setting.

You will work with Kafka, MongoDB, Oracle, and perform rigorous testing while mentoring junior developers and contributing to best practices.

Qualifications

• 7+ years of experience in Java development
• Extensive experience with Spring Framework, Spring Boot and Spring Cloud
• Proven track record of designing and implementing microservices architecture
• Experience with Reactive programming
• Proficiency with Apache Kafka and event-driven systems
• Strong MongoDB experience with schema design and performance optimization
• Solid understanding of NoSQL concepts and best practices
• Experience with Oracle SQL and performance tuning
• Expertise in RESTful API design principles
• Proficiency in unit and integration testing (JUnit, Mockito)
• Knowledge of application security principles and secure coding practices
• Experience implementing OAuth 2.0/JWT in microservices architectures

Responsibilities

• Design, develop, and maintain robust, scalable Java-based backend services
• Architect and implement microservices using Spring Framework 6, Spring Boot 3 and Spring Cloud
• Design and implement event-driven architectures using Apache Kafka
• Work with MongoDB and Oracle - design schemas and optimize queries
• Implement and maintain comprehensive unit and integration tests
• Participate in code reviews and mentor junior developers
• Contribute to continuous improvement of development processes and best practices

Skills

Java development

Spring Framework

Microservices

Reactive programming

RESTful APIs

OAuth 2.0 / JWT

JUnit & Mockito

Tools

Docker

Kubernetes

Apache Kafka

MongoDB

Oracle

SQL

CI/CD

Job description

Citigroup Inc. in Mississauga, Canada is seeking a Senior Java Backend Developer to join CitiDirect’s payments platform modernization. You will craft Java-based backend services, emphasizing Spring Framework, microservices, and secure APIs in a fast-paced financial setting.

You will work with Kafka, MongoDB, Oracle, and perform rigorous testing while mentoring junior developers and contributing to best practices.