Flagship Financial Group

Senior Software Engineer, Full Stack
Chadds Ford, PA | Coppell, TX | Tempe, AZ | Remote
Auto financing is one of the largest consumer credit markets in the U.S. - and one of the most overdue for modernization. We're building a new generation of Auto Lending products - from a Dealer Portal to a full Dealer Management System and CRM. On the horizon: a direct-to-consumer Auto Loan experience and an Auto Refinance product.
These are greenfield, high-impact products built on a clean, modern stack - and we're moving fast.
We are looking for a Senior Full Stack Engineer who thrives in a startup-like environment inside an established auto lender - someone who can architect and ship production code across the front end and back end, integrate with mission-critical partners (e.g., credit bureaus, dealer systems, vehicle data providers), and set the engineering bar for the team. This is a core role with real technical ownership from day one and a direct line of sight into the products that power our business.
Key Responsibilities
Design & Development

• Architect, build, and operate the full-stack services and user experiences that power loan origination, decisioning, and servicing our new Flagship Platform.
• Ship features end-to-end across our stack: Next.js on the front end, C# / .NET on the back end, PostgreSQL for data, and AWS ECS for infrastructure.
• Translate complex financial and operational workflows into clean, performant, well-tested code that holds up under regulatory scrutiny and production load.

API & Platform Integration

• Lead integrations with credit bureaus (Experian, Equifax, TransUnion), dealer systems (DealerTrack, RouteOne), fraud and verification providers, and other third-party partners - including contract design, retry/idempotency strategy, and operational runbooks.
• Extend and customize our existing DEFI Solutions loan originations platform - configuring workflows, scorecards, rules, and decision flows, and developing services that integrate with DEFI via REST APIs and operational data store (MSSQL).

Feature Ownership

• Collaborate directly with Product, Design, and business stakeholders on features from problem framing through production rollout and post-launch iteration.
• Drive observability, performance, reliability, and security across the services you own.

Code Quality & Engineering Practices

• Set the patterns for testing, observability, security, and CI/CD that the rest of the team adopts.
• Leverage AI-assisted development practices and tools (Copilot, Cursor, Claude Code, and similar) to accelerate delivery without sacrificing quality.
• Run design reviews, give technical guidance, and help onboard the engineers who join after you.

Minimum Qualifications

• Work Authorization: Applicants must be authorized to work in the U.S.
• Experience: 5+ years of professional software engineering experience.
• Full Stack Depth: Production experience building and operating modern web applications across both front and back end. Expert-level proficiency in C# / .NET and a modern React-based framework (Next.js strongly preferred).
• Data & APIs: Strong working knowledge of PostgreSQL (or a comparable relational database), RESTful API design, and SQL Server / T-SQL.
• Cloud & Infrastructure: Hands-on experience with AWS, including containerized workloads (ECS, EKS, Fargate, or similar) and Docker.
• Education: Bachelor's degree in computer science, Engineering, or related technical field, or equivalent experience.

Preferred Qualifications

• Direct experience working with or building on DEFI Solutions, or equivalent commercial Loan Origination Systems.
• Auto finance, lending, or other regulated-industry domain experience.
• Experience with event-driven architecture and AWS messaging services (SNS, SQS, EventBridge, Kafka, or similar).
• Experience integrating ML-driven decisioning, scoring, or underwriting models into production systems.