Hybrid Senior Java Backend Engineer: Kafka, MongoDB

Citi; Mississauga; Hybrid; CAD 121,000 - 171,000; Full time

Job summary

Citi is seeking a Senior Java Backend Engineer to design high-performance, event-driven systems at global scale. You will architect reactive microservices, integrate real-time data streams, and ensure engineering quality across a modern Java stack.

You will mentor engineers, collaborate with product and architecture teams, and contribute to features that impact Citi’s clients worldwide. This full-time role offers hybrid work arrangements in a major tech hub.

Qualifications

• Experience building and scaling Java applications.
• Proficiency with Spring WebFlux, Project Reactor, or RxJava.
• Experience with Apache Kafka and real-time data streams.
• NoSQL data modelling with MongoDB and search with Elasticsearch.
• Strong unit testing with JUnit and code coverage.

Responsibilities

• Build and deploy asynchronous, event-driven microservices in Java.
• Design reactive backend services using Spring WebFlux and reactive libraries.
• Develop real-time event streaming pipelines with Kafka.
• Engineer search/analytics with Elasticsearch for large data sets.
• Architect and optimise MongoDB data persistence.
• Lead test-driven development and code reviews to ensure quality.
• Mentor mid-level engineers and promote coding standards.
• Collaborate with product, infra, and architecture teams on new features.

Skills

Java backend

Reactive programming

Spring WebFlux

Kafka

MongoDB

Elasticsearch

JUnit

Git workflows

CI/CD

Education

Bachelor’s degree

Master’s degree (preferred)

Tools

Docker

Kubernetes

Job description

Citi is seeking a Senior Java Backend Engineer to design high-performance, event-driven systems at global scale. You will architect reactive microservices, integrate real-time data streams, and ensure engineering quality across a modern Java stack.

You will mentor engineers, collaborate with product and architecture teams, and contribute to features that impact Citi’s clients worldwide. This full-time role offers hybrid work arrangements in a major tech hub.