Senior Fullstack Developer

About the role:
We are building a greenfield, document-driven lending platform that automates the full lifecycle of a loan application — from document intake and OCR-based extraction, through human-in-the-loop review, to final approval and downstream submission. The system is a modular monolith with a clear separation between backend services and multiple trust-boundaried web front ends, deployed natively on Azure.
We're looking for a senior full-stack engineer who is equally comfortable designing clean, testable back-end architecture in C#/.NET and building modern, production-grade UI in React/Next.js. You'll work across the stack: domain modeling, API design, background/async processing, and customer- and operations-facing web applications.

Responsibilities

• Design and build business logic and domain modules in an ASP.NET Core API following Clean Architecture principles (Domain, Application, Infrastructure, API layers).
• Build and maintain asynchronous background processing services (a .NET worker) for document-heavy workflows, coordinated through message queues.
• Develop and maintain multiple Next.js/React applications serving different user populations (internal operations/back-office tooling and external/customer-facing portals), sharing a common package layer.
• Design relational data models and write efficient data access code (EF Core / PostgreSQL).
• Integrate with cloud-native infrastructure: message queues, blob storage, secrets management, and managed identity providers.
• Implement authentication and authorization across multiple identity boundaries (workforce vs. external/customer identity).
• Collaborate on API contracts and shared TypeScript types consumed by front-end applications.
• Participate in architectural decisions that keep a growing monolith modular, maintainable, and well-tested (unit, integration, contract, and architecture tests).
• Work within a human-in-the-loop product model: build tooling that lets operators review, correct, and approve AI-assisted extraction results, with full traceability of how each data point changed from raw intake to final approval.
• Write and maintain automated tests across the stack and participate in CI/CD pipeline health.
• Participate in code review, technical design discussions, and mentor less experienced engineers.

Requirements

• 8+ years of professional software development experience, with deep expertise in C# / .NET (ASP.NET Core).
• 4+ years building production front-end applications with React, including Next.js (App Router, server components/actions, route handlers).
• Strong understanding of Clean/Layered Architecture, domain modeling, and separation of concerns in non-trivial back-end systems.
• Experience with relational databases and ORMs (EF Core or equivalent), including migrations and query performance.