Senior Software Engineer, Backend

Position Overview

• Location Type: Hybrid
• Job Type: Full-time
• Salary: Not specified

Flex is a growth-stage, NYC headquartered FinTech company creating the best rent payment experience. It’s hard to believe that it’s 2025 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. Will you be a part of the team?

About the Job

Flex is looking for a Software Engineer who will be responsible for implementing the various backend systems that support all business features.

In this role, you will be part of the backend engineer team, responsible for the services and integrations that power our products, such as Payment, Billing, Identity, partner integration, etc. You’ll be designing, developing, testing, and scaling systems needed to deliver great user and partner experiences.

You’ll work closely with your product, design and engineering peers to solve our users' most pressing problems around rent payment. You’ll roll out changes to our customers in an agile manner with a delivery cadence that favors small, frequent iterations. The ideal candidate will be comfortable leading scoping, design and implementation for APIs they build and can drive their production rollouts to completion with minimum oversight.

Requirements

• Minimum Experience: Minimum of 6 years experience in software engineering
• Minimum Java Experience: Minimum of 4 years experience with Java
• Teamwork: Ability to work on a globally-distributed team with a high degree of ownership
• Stakeholder Communication: Experience working with technical and non-technical stakeholders, successfully aligning and setting expectations on scope and delivery
• Adaptability: Ability to grow in a fast-paced and dynamic environment that will challenge you to always bring your best
• System Design: Experience building robust, fault-tolerant systems with multiple external dependencies
• Data Pipelines: Experience designing, building, and maintaining data pipelines
• Technical Proficiency: Proficient in Java frameworks and tools used at Flex, including Spring (core/web/boot), Gradle, JUnit, and JVM (memory/performance tuning, GC).
• Architecture: Experience with Service-Oriented Architecture, REST APIs, Message Queues, and scalable architectures.
• Cloud Experience: Experience with AWS (EKS, Aurora RDS, Elasticache, DynamoDB) and containerization tools.

Preferred Qualifications

• CI/CD: Proficient in CI/CD systems (preferably GitHub Actions), git, and automation.
• Observability: Skilled in observability and monitoring tools, such as DataDog, to ensure high availability.
• Big Data: Experienced with big data platforms and tooling, including Snowflake.
• Infrastructure as Code: Proficient in Infrastructure as Code, using tools like CDK and Terraform.