Staff Software Engineer, Partner Integrations

Flex; United States; Remote; USD 170,000 - 250,000; Full time

Benefits offered by this job

Competitive medical, dental, and vision

Company equity

401(k) plan with company match

Unlimited paid time off + 13 company paid holidays

Parental leave

Free Flex subscription

Job summary

Flex, a leading FinTech company based in New York City, is seeking a Staff Software Engineer for Partner Integrations. This remote role involves designing and implementing payment integration platforms and contributing to high-impact projects. The ideal candidate should have at least 6 years of experience in software engineering, with proficiency in Java and experience with AWS.

Flex offers a competitive compensation package, including benefits such as medical, dental, and equity options. Join us in our mission to empower renters with financial flexibility.

Qualifications

• Minimum 6 years of experience in software engineering.
• Proficient in Java and Spring ecosystem.
• Experience with AWS and microservices.

Responsibilities

• Design, implement, and maintain payment integrations platform.
• Collaborate with cross-functional teams on high-impact features.
• Mentor engineers and uphold engineering standards.

Skills

Java

Spring

REST APIs

AWS

Microservices

CI/CD

Tools

DataDog

Snowflake

Terraform

Job description

Staff Software Engineer, Partner Integrations

Remote

Flex is a growth‑stage, NYC‑headquartered FinTech company that is creating the best rent payment experience. It’s hard to believe that it’s 2026 and paying rent on time is expensive, inflexible, and difficult. We’re here to change that! Flex enables our users to pay rent throughout the month on a schedule that better fits their finances and budget. Our mission is to empower as many renters as possible with flexibility over their most significant recurring expense. After deliberately keeping a stealth profile as we built up unprecedented investor support and an enthusiastic user base, we are looking for motivated individuals to help us keep our mission growing.

What you’ll do

• Design, implement, and maintain our payment integrations platform, including partner APIs, SDKs, and embedded web experiences
• Help shape and drive the technical roadmap for the Partner Engineering team
• Design and develop scalable APIs and integrations to support money movements across our banking partners via payment rails such as ACH
• Work cross‑functionally with Engineering, Product, Design, Infrastructure, Sales, Partner, and Customer Success to deliver high‑impact features
• Scale our integrations platform to support business growth while maintaining performance and reliability
• Continuously improve daily operations through automation, tooling, design evolution, and observability
• Mentor engineers and elevate team standards through best practices, code reviews, and technical guidance

Requirements

• Minimum 6 years of experience in software engineering
• Minimum 4 years of experience with Java; proficient in Spring (core/web/boot), Gradle, JUnit, and JVM tuning
• Experience with Service‑Oriented Architecture, REST APIs, message queues, and scalable distributed systems
• Experience with AWS (EKS, Aurora RDS, Elasticache, DynamoDB) and containerization
• Experience leading delivery of multiple high‑impact products end to end, on time with a high quality bar
• Ability to work on a globally‑distributed team with a high degree of ownership
• Experience aligning technical and non‑technical stakeholders on scope and delivery
• Experience in FinTech and familiarity with major payment rails
• Ability to drive quality and consistency across your team without compromising velocity

Preferred

• Proficient in CI/CD systems (preferably GitHub Actions) and automation
• Skilled in observability and monitoring tools such as DataDog
• Experienced with big data platforms including Snowflake
• Proficient in Infrastructure as Code (CDK, Terraform)
• Excellent written and verbal communicator with cross‑functional collaboration experience

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.

$200,000 - $250,000 USD

$180,000 - $225,000 USD

Tier 3 (Salt Lake City, all other USA cities)

$170,000 - $212,500 USD

Life at Flex

We understand that it takes a diverse team of highly intelligent, curious, determined, empathetic, and self‑aware people to grow a successful company. Our HQ is located in New York City, but we have employees located throughout the US, Australia, Canada and South America. We are growing quickly, but deliberately, with a focus on building an inclusive culture. Our dynamic team has incredible perspectives to share, just as we know you do, and we take great pride in being an equal opportunity workplace.

Benefits

• Competitive medical, dental, and vision
• Company equity
• 401(k) plan with company match
• Unlimited paid time off + 13 company paid holidays
• Parental leave
• Free Flex subscription

Flex is an equal‑opportunity employer. We do not discriminate on the basis of any protected group status under any applicable law.