SlipstreamJobs tracks this role from the company's public career site. Apply directly on the employer's site.
Salary: USD 146,200 - 215,000 / annual
Flex is a growth-stage fintech company headquartered in NYC that is transforming how renters pay rent. The company enables users to pay rent throughout the month on a flexible schedule that fits their finances, rather than requiring a single lump-sum payment. Flex is looking for a Senior Backend Engineer to design, build, and scale the services and integrations powering Payment, Billing, Identity, and partner integrations.
In this role, you will own the design and implementation of APIs across Payment, Billing, Identity, and partner integration domains. You will lead scoping and design efforts, drive your own production rollouts with minimal oversight, and work closely with product, design, and engineering peers to solve renters' most pressing problems through small, frequent iterations rather than big, risky releases. You'll work on one of three teams: Partner Integrations (standardizing APIs and tools for external partners), Fin Platform (monitoring and operations layer for billing and payment systems), or Money Team (payments, wallet, and settlement finance systems).
The ideal candidate is a doer who gets things done efficiently, an owner who takes full accountability from design through production, collaborative in pressure-testing ideas, precise in both code and communication, resilient when systems break or priorities shift, and humble about finding the right answer.
Flexibility and autonomy are core to the role. You'll work on a globally-distributed team with high ownership expectations. The company has offices in New York, San Francisco, and Salt Lake City (hybrid, 2-3 days/week on-site for those locations), but remote work is available for candidates outside these areas. Flex also offers relocation assistance for eligible candidates.
REQUIREMENTS:
Minimum Qualifications:
- 6+ years of software engineering experience
- 4+ years of experience with Java
- Ability to work on a globally-distributed team with high degree of ownership
- Experience working with technical and non-technical stakeholders, successfully aligning and setting expectations on scope and delivery
- Ability to grow in a fast-paced and dynamic environment
- Experience building robust, fault-tolerant systems with multiple external dependencies
- Experience designing, building, and maintaining data pipelines
- Proficiency in Java frameworks and tools: 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
Preferred Qualifications:
- Proficiency in CI/CD systems (preferably GitHub Actions), git, and automation
- Skilled in observability and monitoring tools such as DataDog
- Experience with big data platforms and tooling, including Snowflake
- Proficiency in Infrastructure as Code using tools like CDK and Terraform
- Skilled at elevating team standards through best practices and mentoring junior engineers
- Excellent written and verbal communicator with experience in cross-functional collaboration
