Senior Backend Engineer (Full Stack Mindset)

Employment Type: Full-time Location Type: Remote

About EarnIn

EarnIn is a pioneer in earned wage access, dedicated to providing real-time financial flexibility for individuals living paycheck to paycheck. Our community members can access their earnings as they earn them, with options to spend, save, and grow their money without mandatory fees, interest rates, or credit checks. We are backed by an experienced leadership team and world-class funding partners such as A16Z, Matrix Partners, DST, and Ribbit Capital, with a strong core business and significant growth potential. We are actively seeking talented individuals to join us in shaping the next phase of our expansion.

Position Overview

The Core UX Team at EarnIn is seeking a Senior Backend Engineer with a Full Stack Mindset. This role is crucial for developing foundational services that power user-facing experiences across EarnIn's mobile and web platforms. The ideal candidate excels at the intersection of product and platform, bringing a backend-first perspective combined with a strong understanding of user experience needs. You will be comfortable working across service layers, infrastructure, and collaborating with frontend and mobile engineers to deliver cohesive features.

In this role, you will be responsible for designing and evolving Kotlin-based services, enhancing system reliability (including background workflows and queues), and enabling scalable product experiences used by millions of members daily.

Salary Range: $186,300 - $227,700 annually, plus equity and benefits. Salary is determined by role, level, and location.

What You'll Do

• Design, implement, and evolve Kotlin-based backend services supporting key user-facing product features.
• Deconstruct complex product and system requirements into clean, scalable service architectures.
• Build and maintain asynchronous workflows, including job execution, messaging patterns, and queue-based processing.
• Contribute to the design and rollout of robust REST/gRPC APIs and data contracts for mobile and web clients.
• Collaborate closely with mobile, frontend, product, and design teams to ensure platform consistency and cohesion.
• Own the reliability, observability, and performance of your services in production environments.
• Write well-tested, maintainable code and participate in continuous integration pipelines and automation frameworks.
• Participate in incident response and root cause analysis to improve system resilience.
• Provide technical guidance and mentorship to other engineers through design reviews, pair programming, and architecture discussions.
• Contribute to team-wide planning and influence engineering strategy within the Core UX domain.
• Actively collaborate across domains, including product, data, finance, and analytics, to align services with business needs.

What We're Looking For

• 5+ years of software engineering experience with a proven track record of shipping and maintaining backend services.
• Strong Kotlin experience, particularly in backend systems.
• Proven experience in microservice-based architectures and event-driven communication models.
• Hands-on experience designing and implementing REST/gRPC APIs and messaging workflows.
• Solid understanding of SQL databases, schema design, and performance optimization.
• Familiarity with distributed systems, including monitoring, alerting, and failure handling.
• Experience working with CI/CD pipelines and production deployment practices.
• Effective communication and collaboration skills across different time zones and teams.
• Experience mentoring other engineers and providing technical leadership.
• Exposure to frontend or mobile client integration is a plus.
• Proactive interest in working with AI tools and on AI-driven solutions; opportunities to use generative AI will be available.