Backend Senior Infrastructure Engineer

Sunbit builds financial technology for real life.

Our technology eases the stress of paying for life’s expenses by giving people more options on how and when they pay. Founded in 2016, Sunbit offers a next-generation, no-fee credit card that can be managed through a powerful mobile app, as well as a point-of-sale payment option available at more than 25,000 service locations, including auto dealership service centers, optical practices, dentist offices, veterinary clinics, and specialty healthcare services. Sunbit was included on the 2022 Inc. 5000 list.

The financial technology company has also been named a Most Loved Workplace®, Best Point of Sale Company, and a Top Fintech Startup by CB Insights. We use cutting-edge innovations in financial technology to bring leading data and features that allow individuals to be qualified instantly, making purchases at the point of sale fast, fair, and accessible for consumers from all walks of life. We create value focused on our core values; we work tirelessly to ensure that Sunbit becomes available to everyone, everywhere.

We invite you to #UnleashYourCuriosity and join our ever-growing R&D organization.

What You’ll Do:

Sunbit is looking for a Senior Backend Infrastructure Engineer to join our Infrastructure Group, the team responsible for building and scaling the shared services and core systems that power Sunbit’s entire engineering ecosystem.

As part of the Infrastructure Group, you will play a critical role in providing the backbone of Sunbit’s technology, enabling development teams to move faster, more reliably, and more efficiently.

You will lead the design and implementation of cross-team services, accelerate the work of product and platform teams, and act as a pivotal force in driving complex, high-impact technical initiatives across the organization.

This is a hands-on engineering position that blends deep technical expertise with leadership, delivering robust and scalable infrastructure solutions that directly influence the success of Sunbit’s core products.

Responsibilities:

Own and Scale Core Services - Design, develop, and maintain reliable, high-performance, and highly available backend services used across Sunbit’s engineering teams.

Advance Backend Infrastructure & Tooling - Continuously evolve our engineering foundations — from CI/CD frameworks to internal tooling — improving development velocity, observability, and system reliability.

Drive Cross-Team Technical Initiatives - Collaborate with product, platform, and backend teams on strategic projects. Serve as a force multiplier by enabling feature teams through shared infrastructure and backend leadership.

Lead Innovation and Technical Direction - Champion innovation in tooling, architecture, and best practices. Lead the adoption of new technologies and modern approaches to future-proof Sunbit’s infrastructure.

Requirements:

8+ years of backend development experience, primarily with JVM-based stacks (Java/Kotlin).

Proven track record as a technical leader, enabling and accelerating the work of others.

Expertise in building core infrastructure services, internal tooling, and shared backend frameworks.

Deep experience with microservices, cloud-native architecture (preferably AWS), and Kubernetes orchestration.

Strong command of both SQL and NoSQL databases, including designing for scale and performance.

Proficient in asynchronous communication patterns, including production use of Kafka.

Solid grasp of Domain-Driven Design (DDD) principles and their practical application.

Experience designing and securing scalable REST APIs.

History of introducing new frameworks and technologies that improve engineering outcomes.

Excellent collaboration and communication skills across engineering disciplines.

Preferred Experience

Deep hands-on experience with the AWS ecosystem

Proficiency in the Spring Framework and building production-grade backend services

Experience with event streaming platforms (Kafka or similar)

Background in payment systems or financial services

Collaboration with Machine Learning teams and integration of ML features into production systems

Strong Kubernetes expertise — from architecture to deployment and workload management