Sr. Software Engineer

Rakuten Rewards•Toronto, ON

8d•CA$107,957 - CA$157,957

About The Position

Rakuten International is a division of Rakuten Group, Inc., a Japanese global technology leader in services that empower individuals, communities, businesses and society. Headquartered in San Mateo, California with more than 4,000 employees worldwide, the Rakuten International business portfolio includes market leaders in e-commerce, digital marketing, advertising, communications and entertainment. We create products and services that provide exceptional value by aligning members and the businesses that want to engage them in a shared community. Rakuten is the most rewarding way to shop, giving millions of members Cash Back when they buy from their favorite brands. As a leading shopping platform, Rakuten partners with thousands of top brands across apparel, beauty and wellness, grocery, travel, on-demand services, subscriptions, and dining, helping members save on everyday purchases. Since 1999, Rakuten members have earned more than $4.6 billion in Cash Back, making it the largest Cash Back platform of its kind. Learn more at Rakuten.com. In this role, you will design, develop, and improve backend systems to meet user needs and business objectives. You will work through ambiguous requirements, contribute to clear specifications, leverage AI tools to rapidly build and refine high-quality code, and collaborate cross-functionally to deliver scalable backend solutions. Your role will involve debugging and improving existing systems, ensuring optimal performance, and integrating new features to enhance functionality. With a strong foundation in systems thinking and adaptability, you will continuously improve how software is designed, built, and operated in an AI-assisted development environment.

Requirements

Production-level application development experience using Java.
Production-level application development experience using Node.js.
Familiarity with service-oriented architecture concepts, principles, and patterns.
Hands-on experience with cloud platforms (e.g., AWS, GCP, or Azure) and familiarity with services like EC2, Lambda, API Gateway, Apache Kafka, and S3.
Experience with database technologies and a strong understanding of database schema design
Experience with event-driven architectures.
Exposure to automated CI/CD pipelines (e.g., Jenkins, GitHub Actions).
Basic troubleshooting experience with observability tools like Datadog or similar.
Demonstrated ability to validate and debug complex systems, including AI-generated code.
Experience using AI-assisted development tools (e.g., Claude, Copilot, Cursor) to generate, evaluate, and refine code.
Ability to reason about system behavior, identify tradeoffs, and make sound technical decisions in ambiguous situations.
Excellent written and verbal communication skills, with the ability to clearly articulate technical concepts, decisions, and tradeoffs across cross-functional teams.
B.S. in Computer Science or related field, or equivalent experience required.
5-8 years relevant work experience required.
2+ years of production-level application development experience using Java/J2EE, ideally with frameworks like Quarkus or Spring.
2+ years of production-level application development experience using Node.js, ideally with frameworks like Serverless or AWS SAM.
Demonstrated ability to learn new technologies and adapt quickly in a rapidly evolving development environment.

Nice To Haves

Experience with additional programming languages such as Python or Go.
Familiarity with a Frontend JavaScript Framework, like React, Vue.js, or Angular.
Experience refactoring legacy systems to modern architectures.
Familiarity with spec-driven development, including the ability to clarify ambiguous requirements and define clear system behavior.
Strong product intuition and attention to user experience when designing solutions.

Responsibilities

Design and evolve backend architecture end-to-end, including APIs, data models, and storage.
Establish clear specifications, contracts and behaviors that enable reliable scaling and effective AI-assisted development.
Contribute to architectural decisions and communicate tradeoffs across simplicity, performance, and long-term maintainability.
Use AI tools to generate, iterate on, and refine implementations, producing clean, maintainable code aligned with established specifications and Rakuten engineering standards.
Exercise strong judgment in evaluating and validating AI-generated output.
Work across engineering, product, and design to navigate ambiguous problems, shape technical direction, and align on priorities and tradeoffs.
Help shape what should be built, not just how it is implemented, with a focus on delivering meaningful user and business impact.
Act as a mentor to junior team members on best practices for AI-assisted workflows, code quality, and system design.
Develop and implement testing, validation, and monitoring strategies to ensure correctness of AI-generated code.
Proactively identify edge cases, failure modes, and inconsistencies.
Build services that are performant, testable, and resilient in production.
Implement monitoring, logging, and feedback loops to drive continuous improvement.
Debug complex production issues and drive them to resolution in collaboration with the team.
Adapt quickly to new tools and paradigms, using AI to accelerate development, prototype rapidly, and continuously improve engineering workflows and operational practices.