Senior Full Stack .NET Engineer

Experience: 5+ years

Required Skills: C#, .NET, React/Next.js, PostgreSQL, AWS, REST APIs, SQL Server

Job Summary

We are looking for an experienced Senior Full Stack .NET Engineer to design, develop, and maintain scalable applications for a flagship loan origination, decisioning, and servicing platform. The ideal candidate will have strong expertise in C#/.NET, React-based front-end development, database technologies, and AWS cloud infrastructure, with end-to-end ownership of feature delivery and third-party integrations.

Key Responsibilities

• Design, develop, and maintain full-stack applications using Next.js, React, C#/.NET, PostgreSQL, and AWS .
• Build scalable, secure, and high-performance RESTful APIs and backend services.
• Integrate third-party systems, including credit bureaus, dealer platforms, fraud detection, and identity verification providers.
• Configure and extend the DEFI Solutions Loan Origination System (LOS) , including workflows, business rules, scorecards, and decision flows.
• Develop integrations with DEFI using REST APIs and Microsoft SQL Server.
• Deploy and manage containerized applications using AWS ECS/EKS, Fargate, and Docker.
• Collaborate with Product, Design, and Business teams to deliver features from requirements through production deployment.
• Ensure code quality, automated testing, performance, security, observability, and system reliability.
• Participate in code reviews, technical design discussions, and mentoring of team members.
• Leverage AI-assisted development tools such as GitHub Copilot, Cursor, and Claude Code to improve engineering productivity.

Required Skills & Qualifications

• 5+ years of professional software development experience.
• Strong hands-on expertise in C#, .NET/.NET Core, and modern full-stack application development .
• Experience with React and Next.js for front-end development.
• Strong knowledge of PostgreSQL or other relational databases, SQL Server, and T-SQL.
• Experience designing and integrating RESTful APIs.
• Hands-on experience with AWS cloud services, containerization, and Docker.
• Knowledge of CI/CD pipelines, automated testing, application security, and performance optimization.
• Bachelor’s degree in Computer Science, Engineering, or a related field, or equivalent practical experience.

Preferred Qualifications

• Experience with DEFI Solutions or other Loan Origination Systems (LOS) .
• Domain experience in auto finance, lending, banking, or other regulated industries.
• Knowledge of event-driven architecture and messaging services such as AWS SNS, SQS, EventBridge, or Kafka.
• Experience integrating machine learning-based scoring, decisioning, or underwriting models into production applications.
• Experience with AI-assisted coding and development tools.

Must-Have Skills for Screening

C#/.NET + React/Next.js + AWS + REST APIs + SQL/PostgreSQL

Good to Have: DEFI Solutions / Loan Origination Systems, lending or auto-finance domain, Kafka or AWS messaging services.