Fullstack Engineer

Koalafi•Arlington, VA

1d•Onsite

About The Position

Koalafi is building a net-new Non-Prime Installment Loan product — a greenfield initiative that expands our financing options for customers who don't fit traditional prime credit profiles. This is a meaningful product with real impact: more customers funded, more merchants closing sales they'd otherwise lose. You'll be part of a focused product team (product manager + tech lead + engineers) responsible for integrating Koalafi's platform with a third-party loan servicing system and building the internal capabilities to support the full loan lifecycle — origination, servicing, payments, and communications. You'll be doing real work on a real product from day one, not maintaining something someone else built years ago. That said, this isn't a build-in-a-vacuum situation. The NPIL product connects to existing Koalafi systems — origination, payments, communications — and you'll need to be comfortable rolling up your sleeves and navigating code you didn't write. That's the job. The ability to read an unfamiliar codebase, understand its intent, and make a clean change is just as important as building new things.

Requirements

2–4 years of professional software engineering experience
Hands-on experience building backend services in Golang
Working knowledge of REST APIs, HTTP/JSON patterns, API authentication including bearer tokens and OAuth flows and API Testing tools like Postman, HTTPPIe
Experience building or contributing to frontend applications; React/TypeScript preferred
Familiarity with AWS, Kubernetes, and cloud-native deployment patterns
Familiarity with observability concepts and tools like Dynatrace
Familiarity with AGILE/Scrum principles, ceremonies and JIRA
Solid testing instincts — unit, integration, and contract testing aren't afterthoughts for you
Comfort navigating and contributing to unfamiliar codebases — not just greenfield builds
Strong communication skills: you can explain what you're building and why, not just how
Location Requirement: This position requires regular in-person attendance at one of our two office locations (Richmond, VA or Arlington, VA). Candidates must already be located within a commutable distance to either location, as relocation assistance is not available at this time

Nice To Haves

Experience with event-driven or asynchronous messaging patterns
Background in fintech, lending, payments, or other financial services
Familiarity with third-party financial platforms (LoanPro, Peach, Amount, or similar)
Experience with feature flags and gradual rollout strategies
Interest in leveraging AI tools to accelerate development velocity
Secret Management using AWS Secret Manager

Responsibilities

Implement microservices and event-driven workflows to integrate Koalafi's systems with a third-party loan servicing platform
Build and maintain REST APIs that support loan origination, payment processing, and customer servicing operations
Navigate and contribute to existing internal services where the NPIL product intersects with current Koalafi systems — reading unfamiliar code, understanding its intent, and making clean, well-scoped changes
Develop frontend components in React/TypeScript to support customer-facing and internal tooling as needed
Write code that is testable, observable, and built to last — not just built to ship
Work closely with the Tech Lead on system design and integration architecture
Partner with Product and Compliance to understand requirements and translate them into reliable, compliant implementations
Participate in code reviews — both giving and receiving feedback with the goal of raising the bar, not just checking a box
Engage actively in sprint ceremonies: planning, retros, standups — contribute to the team's rhythm, not just your own ticket
Implement monitoring and alerting at integration points so issues surface before customers notice them
Support audit logging and data reconciliation requirements inherent to a regulated financial product
Identify and flag technical risk early — bad news early is always better than bad news late
Leverage AI development tools to move faster and stay consistent with team patterns