Senior Software Engineer (.Net Core + LLM's)

About Aperia Solutions
Aperia Solutions is a leading payments SaaS company headquartered in Dallas, Texas. We build risk management, residuals accounting, compliance, and analytics platforms used by merchant banks, ISOs, payment processors, and other participants in the credit card payments ecosystem. Operating under PCI DSS 4.0 compliance across dual on-premises datacenters (Allen, TX and Chicago, IL) plus Azure cloud, we process high-volume payment data for some of the industry’s largest players.
We’re in the middle of a significant platform modernization program: a next-generation risk analysis and scoring platform on Microsoft Fabric, an AI-powered ingestion platform, new AI-native applications, and ongoing evolution of the products our clients rely on every day. The teams executing this work are deliberately small and senior, with executive-level support and minimal bureaucracy. Every senior hire is a founding contributor to the architecture and the code.
About the Role
Aperia is hiring a mid-senior level software engineer to join the team building our next-generation risk analysis and scoring platform, with opportunities to contribute across our wider product portfolio — the AI-powered ingestion platform, residuals and compliance products, and client-facing web applications. You’ll work under the technical direction of our Lead Software Engineer, alongside a Senior Data Platform Engineer and a Senior DevOps engineer, with big-picture system design owned by dedicated architects. It’s a deliberately small, senior-leaning team — which means real features, real code review, and real growth, not ticket-grinding.
Day to day, you’ll build production C#/.NET services and REST APIs, develop React frontends for client-facing applications, and contribute to our Python-based agentic work as you grow into it. This is a role for an engineer with a few strong years behind them who wants to level up fast: you’ll get direct mentorship from senior engineers, exposure to a modern Azure/Kubernetes platform, and a team culture that treats AI-assisted development as a first-class skill.
What You’ll Do
Build and ship production C#/.NET services and REST APIs serving high-volume payment data under PCI DSS constraints.
Develop client-facing web application features in React and TypeScript, from component work through API integration.
Own well-scoped features end to end on the risk platform build — design discussion, implementation, code review, testing, and deployment.
Contribute to our LangGraph-based agentic application — tool integrations, tests, and evals — growing your Python and LLM-engineering skills along the way.
Write automated tests (unit, integration, end-to-end) as part of everyday development, and participate actively in code review — giving feedback, not just receiving it.
Ship through Azure DevOps CI/CD pipelines to AKS, with support from the team’s DevOps engineer.
Use AI-assisted development tools (Claude Code, Cursor, GitHub Copilot) as a core part of your workflow, following documented team standards.
Pair with senior engineers and participate in design reviews, growing toward ownership of larger workstreams across the portfolio.
What You Bring
3–5 years of professional software engineering experience shipping production systems.
Solid C#/.NET skills — ASP.NET Core, REST API design, and comfort working in an established service architecture.
Working proficiency in TypeScript and React, with production frontend experience.