Staff Software Engineer, Backend

Posted: 2026-09-14

Flex is a growth-stage, NYC headquartered FinTech company that is building the payment layer for life's financial obligations, giving households one place to see, split, and pay their bills around how they live and get paid. By offering greater choice over how and when payments are made and allowing eligible on time payments to help build a positive credit history, Flex puts households back in control of their cash flow.

That work brings together people with different perspectives who challenge the status quo and take ownership of solving difficult problems. For you, that means doing the best work of your career next to people who make you better, and together bringing ideas to life that make a real impact for the people we serve.

- Minimum of 8 years experience in software engineering

- Minimum of 6 years experience with Java

- Proven ability to set technical direction and architecture for complex, distributed systems

- Ability to lead and mentor engineers, raising the technical bar across a team or org

- Ability to work on a globally-distributed team with a high degree of ownership

- Experience working with technical and non-technical stakeholders, successfully aligning and setting expectations on scope and delivery

- Experience building robust, fault-tolerant systems with multiple external dependencies

- Experience designing, building, and maintaining data pipelines

- Proficient in Java frameworks and tools used at Flex, including Spring (core/web/boot), Gradle, JUnit, and JVM (memory/performance tuning, GC)

- Experience with Service-Oriented Architecture, REST APIs, Message Queues, and scalable architectures

- Experience with AWS (EKS, Aurora RDS, Elasticache, DynamoDB) and containerization tools

- Proficient in CI/CD systems (preferably GitHub Actions), git, and automation

- Skilled in observability and monitoring tools, such as DataDog, to ensure high availability

- Experienced with big data platforms and tooling, including Snowflake