Jobs › Companies › Flex › Senior Software Engineer, Backend

About this Senior Software Engineer, Backend role at Flex

Flex · Hybrid · USA

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 USD
Tier 2 (Austin, Washington D.C. Philadelphia, San Diego, Chicago, Atlanta)
$154,800—$193,500 USD
Tier 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.

Ready to apply to Flex?
Apply to Flex

How this Software Engineer salary compares

This role pays $193,500/yr — in line with the typical range for Software Engineer roles.

$116,563 median $185,000 $265,000

Typical range $145,000–$222,500/yr, from 9,014 comparable Software Engineer listings on JobsRadar (pay annualized to USD). See Software Engineer salary insights →

Similar jobs

SA
Senior Software Engineer, AI Developer Experience
Sanity
⚡ Apply early Remote in the United States · location restricted
● New 👁 Seen ✓ Applied 3h ago
Plane Software, Inc.
Software Engineer, AI Application
Plane Software, Inc.
⚡ Apply early United States Onsite
● New 👁 Seen ✓ Applied 3h ago
Plane Software, Inc.
Software Engineer, Full Stack
Plane Software, Inc.
⚡ Apply early United States Onsite
● New 👁 Seen ✓ Applied 3h ago
Plane Software, Inc.
Software Engineer, Mobile (Flutter)
Plane Software, Inc.
⚡ Apply early United States Onsite
● New 👁 Seen ✓ Applied 3h ago
Plaud
Software Development Engineer in Test
Plaud
⚡ Apply early San Francisco, CA Hybrid $114,000–$176,000
● New 👁 Seen ✓ Applied 3h ago
Kong
Software Engineer
Kong
⚡ Apply early Toronto, Canada Hybrid CA$118,000–CA$140,000
● New 👁 Seen ✓ Applied 3h ago
Elliptic
Senior Software Engineer - Data
Elliptic
⚡ Apply early New York, United States Hybrid $206,000–$255,000
● New 👁 Seen ✓ Applied 3h ago
CrowdStrike
Sr. Software Engineer - Sensor, MacOS (Hybrid)
CrowdStrike
⚡ Apply early USA - Sunnyvale, CA Hybrid
● New 👁 Seen ✓ Applied 3h ago
Redwood Materials
Embedded Software Engineer – Power Electronics, Energy Storage
Redwood Materials
⚡ Apply early San Francisco, California, Uni... Onsite $180,000–$237,500
● New 👁 Seen ✓ Applied 3h ago

Sign up for suggestions tailored to the jobs you open and the searches you save.

More jobs at Flex

See all jobs at Flex →

Apply now
🤖

Whoa — hold up

JobsRadar was built for real people having a rough time in their job search — not for automated requests. You're clicking way too fast and you're now temporarily blocked.

Come back later. If you're genuinely job hunting, we've got your back — just act like a human.

Catch your next role the second it’s posted.

Create a free account and we’ll watch the boards for you — the instant a job matches your search, it lands in your inbox or Telegram. No digging, no refreshing.

Create free account

Free forever · takes 30 seconds · already have one?

Get an edge on your job hunt.

Join our Telegram channel for the stuff that helps you land the role — salary benchmarks, the weekly market pulse, and new-feature drops. No spam, just signal.

Join the channel — it's free