Flex · 8 hours ago
Software Engineer II, Backend
United States
Full-time
Remote
Entry, Mid Level
$179K/yr - $194K/yr
2+ years expFlex is a growth-stage FinTech company based in NYC, focused on creating a better rent payment experience. They are seeking a Backend Engineer to design, build, and scale backend services and APIs that enhance their consumer products and partner integrations.
AppsBillingFinancial ServicesFinTechSoftware
Responsibilities
Design, develop, test, and scale backend services and APIs that power Flex’s products, partner experiences, and internal platforms
Implement the service APIs used by our mobile and web apps to simplify complex rent payment processing
Build robust, fault-tolerant systems that integrate with multiple external dependencies and ensure high reliability
Work closely with cross-functional teams—including Engineering, Product, Design, Infrastructure, Sales, Partner, and Customer Success—to deliver features and integrations that wow both customers and partners
Translate feature requirements into well-structured technical specifications and scalable solutions
Lead scoping, design, and implementation for the APIs you build and drive production rollouts with minimal oversight
Contribute to service-oriented architecture, scalable system design, and internal best practices for distributed services environments
Collaborate with peers to evolve Flex’s technical architecture as the company and product offerings grow
Ensure services are observable and highly available through effective use of monitoring tools and practices
Participate in code reviews, CI/CD improvements, and efforts to increase code quality and stability
Qualification
Required
Strong computer science fundamentals and passion for building scalable backend systems
2–3+ years of professional software engineering experience with a focus on backend services
Proficient in Java with hands-on experience using Flex's core stack: Spring (core/web/boot), Gradle, JUnit
Experience building and maintaining distributed services and APIs at scale in production environments
Familiar with REST API design, mobile API best practices, and service-oriented architectures
Experience building fault-tolerant systems with multiple external dependencies
Skilled in observability and monitoring tools (e.g., DataDog) to ensure high availability
Ability to write high-quality code that is testable, maintainable, scalable, and secure
Demonstrated ability to translate business requirements into technical specifications and deliver high-impact solutions
Excellent communicator who thrives in a collaborative, globally-distributed team environment
Comfortable working with both technical and non-technical stakeholders and setting expectations on scope and delivery
Benefits
Competitive medical, dental, and vision available from Day 1
Company equity
401(k) plan with company match (our company match kicks off at the beginning of 2026)
Unlimited paid time off + 13 company paid holidays
Parental leave
Flex Cares Program
Free Flex subscription
Competitive compensation + company equity
Unlimited PTO
Company
Flex
Flex enables people to pay rent bills on a schedule that fits their personal finances.
201-500 employees
H1B Sponsorship
Flex has a track record of offering H1B sponsorships. Please note that this does not
guarantee sponsorship for this specific role. Below presents additional info for your
reference. (Data Powered by US Department of Labor)
Distribution of Different Job Fields Receiving Sponsorship
Represents job field similar to this job
Trends of Total Sponsorships
2025 (1)
2024 (1)
Funding
Current Stage
Growth StageTotal Funding
unknown2025-03-31Series A
2019-11-01Seed
2019-07-24Pre Seed
Leadership Team
Shragie Lichtenstein
Co-Founder & CEO
Michael Jannain
Staff Software Engineer
Recent News
Flexible Finance, Inc.
2025-10-14
Flexible Finance, Inc.
2025-10-09
2023-12-15
Company data provided by crunchbase