Senior Software Engineer, Backend

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.

About Our Opportunities

Flex exists to make paying rent work the way real life actually works — smoothing out cash flow, helping renters avoid late fees, and letting them build credit instead of falling behind. As a Senior Backend Engineer, you'll design, build, and scale the services and integrations behind Payment, Billing, Identity, and partner integrations that keep rent moving on time for renters every month — leading scoping, design, and implementation for the APIs you own, driving your own production rollouts to completion with minimal oversight, and working closely with product, design, and engineering peers to solve renters' most pressing problems in small, frequent iterations rather than big, risky releases.

About Our Team(s)

We have some really exciting teams who are looking for an amazing engineer like you! Check them out!

Partner Integrations - Partner integrations work to standardize APIs, tools, and processes that let external partners connect to Flex for data sharing and payments across entry points like Flex Anywhere and Quick-Pay

Fin Platform - Fin Platform is the monitoring and operations layer for Flex's billing and payment systems, covering dashboards, SLIs/SLOs, runbooks, deployment and on-call procedures to ensure reliability and readiness.

Money Team - builds and owns the platforms, tooling, and documentation powering Flex's payments, wallet, and settlement finance systems.

Who Thrives Here?

A Doer — you get things done efficiently, and you're comfortable rolling up your sleeves when something's blocking the team.

An Owner — you take full accountability for what you build, from design through production, and you always have a plan B.

Someone Collaborative — you bring people together to pressure-test ideas rather than working in a silo.

Someone with Precision — your code and your communication are both clear, because ideas only matter once others can act on them.

Someone Resilient — systems break and priorities shift, and you adapt without losing momentum.

Someone Humble— you care more about getting to the right answer than being the one who's right.

Qualifications

Minimum Qualifications

Minimum of 6 years experience in software engineering

Minimum of 4 years experience with Java

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

Ability to grow in a fast-paced and dynamic environment that will challenge you to always bring your best

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

Preferred Qualifications

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

Proficient 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

Compensation

Flex takes a market-based approach to pay, and compensation may vary depending on your primary work location. Work locations are categorized into one of three tiers based on a cost of labor index for that geographic area. The successful candidate’s starting pay will be commensurate with their experience, qualifications, and Flex’s internal leveling guidelines and benchmarks.

Tier 1 (NYC/Bay Area, Los Angeles, Seattle)$172,000—$215,000 USDTier 2 (Austin, Washington D.C. Philadelphia, San Diego, Chicago, Atlanta)$154,800—$193,500 USDTier 3 (Salt Lake City, all other USA cities)$146,200—$182,750 USD

Life at Flex

Building a successful company takes a diverse team of intelligent, curious, determined, empathetic, and self-aware people. Our headquarters is in New York City, with employees across the US, Australia, Canada, and South America. We’re growing quickly and deliberately, with a focus on building an inclusive culture. We value the perspectives our people bring and take pride in being an equal opportunity workplace.

Offices

Roles posted in New York, San Francisco, and Salt Lake City are hybrid positions with on-site expectations of 2-3 days per week in our local offices. For candidates outside of these areas, you may be eligible for our relocation assistance program.

Benefits

View our benefits and more at getflex.com/careers.