Senior Backend Software Engineer - FinTech Remote

About the Role

Flex is hiring a Senior Backend Software Engineer to join our dynamic team in revolutionizing the rent payment experience. As a Senior Backend Engineer at Flex, you will play a pivotal role in designing, building, and scaling backend services and APIs that power our innovative products. This is a fantastic opportunity for a Senior Backend Software Engineer looking to work remotely and make a significant impact in the FinTech industry.

What You'll Do

• Design, develop, test, and scale backend services and APIs that power Flex’s consumer products, partner integrations, risk management systems, and core platform services.
• Build and operate robust, fault-tolerant distributed systems with multiple external dependencies.
• Implement service APIs for web and mobile apps, simplifying complex rent payment processing.
• Collaborate closely with Product, Design, Infrastructure, Sales, Partner, and Customer Success teams to deliver features that delight customers and partners.
• Drive the full lifecycle of services and APIs you build, including deployment, monitoring, and optimization for high availability and performance.
• Contribute to evolving Flex’s service-oriented architecture, REST APIs, message queues, and scalable systems design.
• Develop risk management systems such as rules engines, ML-powered fraud detection, and high-scale event ingestion pipelines.
• Mentor junior engineers and help elevate the team’s engineering practices through code reviews, architecture discussions, and technical leadership.

Requirements

• A minimum of 4 years of experience with Java is required for this position.
• 5–6+ years of professional software engineering experience with a focus on backend development.
• Proficient in Java frameworks and tools used at Flex: Spring (core/web/boot), Gradle, JUnit, JVM tuning, and performance optimization.
• Experience operating services in distributed, service-oriented architectures at scale.
• Familiarity with REST API design, mobile API best practices, and message-driven architectures.
• Hands-on experience with AWS (EKS, Aurora RDS, Elasticache, DynamoDB), containerization (Docker/Kubernetes), and Infrastructure as Code (CDK/Terraform).
• Skilled in observability and monitoring tools (e.g., DataDog) to ensure high availability.
• Excellent communicator, comfortable working with distributed teams and cross-functional stakeholders.

Nice to Have

• Experience in risk engineering, rules engine architecture, and implementing risk/fraud/credit policies in production systems is highly valued.
• Experience designing and maintaining data pipelines and working with big data platforms (bonus: Snowflake).

What We Offer

• Competitive medical, dental, and vision benefits.
• Company equity.
• 401(k) plan with company match.
• Unlimited paid time off + 13 company paid holidays.
• Parental leave.
• Flex Cares Program: Non-profit company match + pet adoption coverage.
• Free Flex subscription.

This Senior Backend Software Engineer role offers a unique opportunity to work remotely while being part of a fast-growing FinTech company. If you’re passionate about building scalable systems and want to make a difference in the lives of renters, apply now!