Founding Full Stack Engineer

Founding Full Stack Engineer

(Founding Role, Hybrid) Have any questions? Reach out at [email protected]

About the role

We're looking for a Founding Full Stack Engineer to build our lending platform end-to-end — from the borrower-facing web app through the Django API and the fintech integrations that move money and make loans work. This is a genuinely full-stack codebase, not frontend-with-a-BFF: most features touch both the app and the backend. You'll own problems from ticket to production, raise the engineering bar as the team grows, and work closely with experienced leaders, a cross-functional team, and our vendor partners. The compensation for this role is pay + equity. Flexible New York City hybrid. Full time.

The stack you'll work in

• Frontend: Next.js, React, TypeScript, TanStack React Query, Zustand, React Hook Form + Zod, and a shared component library built on Radix UI + MUI.
• Backend: Django + Django REST Framework, Python, PostgreSQL, Celery, Redis.
• Schema-first API: OpenAPI schema that generates a fully typed TypeScript client - types flow from Django serializers to React components, so schema drift is caught at compile time, not in production.
• Infrastructure: AWS (Elastic Beanstalk and core services), GitHub Actions CI/CD
• Fintech Integrations.

Preferred

• Experience designing and supporting the AI/data-science model lifecycle in fintech - from architecture and prototyping through to production-grade code and application integration, alongside the engineering team.
• Credit risk, underwriting, or cash-flow modeling experience.
• Familiarity with fair-lending, model-risk management, or regulatory requirements (e.g., ECOA / Reg B adverse action).
• Familiarity with MLOps platforms and model serving infrastructure.
• Applied mathematics background - discrete mathematics, complex systems, and mathematical modeling.
• Strong understanding of data structures and distributed systems for large-scale data processing, with an eye for efficient, scalable algorithm and code design.

What you'll own

• Full-stack feature delivery across the borrower app and the Django API - most features span both.
• Fintech integration work: new vendor APIs, reliable webhook handling, retry and reconciliation semantics, and payment and loan-servicing workflows.
• Infrastructure evolution - growing with scale.
• Raising the engineering bar: testing strategy, observability, performance, and security in a regulated lending domain.

Preferred

• Experience designing and supporting the AI/data-science model lifecycle in fintech - from architecture and prototyping through to production-grade code and application integration, alongside the engineering team.
• Credit risk, underwriting, or cash-flow modeling experience.
• Familiarity with fair-lending, model-risk management, or regulatory requirements (e.g., ECOA / Reg B adverse action).
• Familiarity with MLOps platforms and model serving infrastructure.
• Applied mathematics background - discrete mathematics, complex systems, and mathematical modeling.
• Strong understanding of data structures and distributed systems for large-scale data processing, with an eye for efficient, scalable algorithm and code design.

Qualifications

• Strong TypeScript/React (Next.js App Router experience a plus) and strong Python/Django (including Django REST Framework) - this is a genuinely full-stack role.
• Comfortable with PostgreSQL data modeling, Celery/queue-based async patterns, and third-party API integration at production quality (idempotency, retries, webhooks).
• Working AWS knowledge (Beanstalk/EC2, RDS, SQS) - enough to own deploys and debug production.
• Strong familiarity with Git, CI/CD pipelines, and automated deployment.
• A testing habit - you write tests without being asked (Vitest / Testing Library, Playwright, pytest).
• Strong command of AI coding tools, with disciplined verification and data-privacy guardrails.
• Excellent documentation skills and a commitment to organized, understandable code that scales as the team grows.
• Care about correctness with money movement.
• Curiosity about fintech and empathy for users - you're passionate about building technology that solves real-world financial challenges.
• Founding-engineer temperament: owns problems end-to-end, pragmatic about scope, comfortable with ambiguity and vendor quirks; a self-starter who builds without constant oversight.
• Flexible New York City hybrid.
• Background check, in-person New York interview, and references required.

Preferred

• Fintech or lending experience - a plus, not a requirement.
• Experience with schema-first / OpenAPI-driven development and typed API clients.
• Experience with payment processing, loan origination, or loan servicing systems.
• Zero-downtime migration discipline and on-call / runbook experience.
• CS degree or equivalent hands-on experience.

Why Join LendKoi?

LendKoi is a financial technology company that provides credit and a digital financial suite for immigrants. We're on a mission to empower individuals to achieve stability and thrive. We're an early-stage startup backed by Techstars NYC and top angels with an incredible team.

Mission-driven Be part of a mission to provide fair and accessible credit and unlock opportunities for underbanked communities.

At The Frontier Join a company at the frontier of consumer financial technology, credit, and payments.

High-impact role You will shape how thousands first experience and understand us.

Creative Freedom Test ideas, iterate quickly, and bring personality to fintech.

Small, fast team You’ll work closely with the executive team, with plenty of ownership.

Learn a Ton From incredibly talented leaders, and genuinely good people; trust and integrity are at the core of how we operate.

Paid, full-time, flexible hybrid Paid, full-time, flexible hybrid role