Staff Backend Engineer - Payments Platform

Flex; Northern (KY); Hybrid; USD 170,000 - 250,000; Full time

Benefits offered by this job

Company equity

401(k) plan with company match

Unlimited paid time off

13 company holidays

Parental leave

Free Flex subscription

Job summary

Flex is a growth-stage FinTech company focused on improving rent payments. As a Staff Backend Engineer, you will design, build, and scale backend services for Payment, Billing, Identity, and partner integrations, setting long‑term technical direction and guiding cross‑team architecture.

You will lead scoping and implementation with minimal oversight, mentor engineers, and drive best practices across the org while collaborating with product and design to solve renters’ problems through iterative

Qualifications

• Minimum of 8 years experience in software engineering.
• Minimum of 6 years experience with Java.
• Proven ability to set technical direction and architecture for complex, distributed systems.
• Ability to lead and mentor engineers, raising the technical bar across a team or org.
• 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.
• 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.

Responsibilities

• Design, build, and scale backend services for Payment, Billing, Identity, and partner integrations.
• Set long-term technical vision and architecture for owned systems.
• Lead scoping, design, and implementation across teams with minimal oversight.
• Mentor peers and drive consistency and best practices across the org.
• Collaborate with product, design, and engineering to solve priorities in small, iterative releases.

Skills

Java

Distributed systems

Mentoring

Leadership

REST APIs

AWS

Spring

CI/CD

Observability

Big data

Terraform

Data pipelines

Tools

Spring (core/web/boot)

Gradle

JUnit

JVM tuning

AWS (EKS, Aurora, Elasticache, DynamoDB)

GitHub Actions

DataDog

Snowflake

CDK

Terraform

Job description

Flex is a growth-stage FinTech company focused on improving rent payments. As a Staff Backend Engineer, you will design, build, and scale backend services for Payment, Billing, Identity, and partner integrations, setting long‑term technical direction and guiding cross‑team architecture.

You will lead scoping and implementation with minimal oversight, mentor engineers, and drive best practices across the org while collaborating with product and design to solve renters’ problems through iterative