Principal Software Engineer

<h3><span style="color: #1c2333;"><strong>Principal Engineer, Payments&nbsp;</strong></span></h3> <p style="color: !important;"><span style="color: #1c2333;">As a Principal Engineer on the Payments Technology and Engineering team, you'll set technical direction and design best-in-class solutions and do hands-on engineering for products that process millions of B2B payments. The role blends hands-on software development, architecture, coaching, and cross-functional partnership with Product, Architecture, Database, DevOps, Performance Engineering, and Operations — this is not a purely advisory position. You'll bring an AI-first mindset to everything from daily coding to system design, treating agentic AI tooling as a default part of the SDLC rather than an occasional aid. This is a senior individual-contributor role — you'll drive impact through system design, architecture, mentorship, and cross-team influence.</span></p> <h3><strong>What You'll Do:</strong></h3> <p style="color: !important;"><span style="color: #1c2333;"><strong>Technical Leadership &amp; Architecture</strong></span></p> <ul> <li><span style="color: #1c2333;">Define and drive the Payments platform's technical approach, system design decisions, and engineering best practices.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Advance platform scalability, reliability, and observability through API-first and event-driven design, distributed systems, cloud-native architecture, and fault-tolerant patterns (e.g., circuit breakers, retries with backoff, etc.).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Partner with Solution and Enterprise Architects, and with developers, to determine optimal designs for architecture, efficiency, maintainability, and scalability across new and existing capabilities.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Collaborate with Product, Business Operations, and Engineering leaders to align technical solutions with business needs and shape engineering roadmaps.</span></li> </ul> <p>&nbsp;</p> <p style="color: !important;"><span style="color: #1c2333;"><strong>AI-First Engineering</strong>&nbsp;</span></p> <ul> <li><span style="color: #1c2333;">Adopt an agentic AI-based SDLC as the default approach to building software — using AI coding agents to scaffold, implement, test, and review code, not just as an occasional assist.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Work fluently with AI harness / coding-agent tools (e.g., Cursor, Claude Code, VS Code with GitHub Copilot) as part of your daily workflow and help establish team-wide standards and best practices for their use.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Champion AI-driven engineering practices — intelligent automation, predictive analytics, and self-healing systems — to improve development efficiency and system resilience.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Identify and implement AI-based solutions for Payments product initiatives, from proof of concept through production.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Model and promote an AI-first mindset across the team — evaluating new AI tooling, sharing what works, and pushing the team toward higher leverage.</span></li> </ul> <p>&nbsp;</p> <p style="color: !important;"><span style="color: #1c2333;"><strong>Quality, Security &amp; Delivery</strong>&nbsp;</span></p> <ul> <li><span style="color: #1c2333;">Solve problems, debug, and optimize code for performance and security, with attention to the compliance and regulatory standards that apply to payment processing (e.g., PCI-DSS).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Own code quality and unit test coverage; partner with QA to design and review test cases so the platform meets customer expectations.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Perform code reviews and approve pull requests, ensuring code follows documented standards and best practices.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Own the health of the software delivery pipeline and guide the team in improving it.</span></li> </ul> <p>&nbsp;</p> <p style="color: !important;"><span style="color: #1c2333;"><strong>Hands-On Development, Mentorship &amp; Collaboration</strong></span></p> <ul> <li><span style="color: #1c2333;">Stay hands-on — writing code, building proofs of concept, and pairing directly with engineers — while also setting architectural direction; this role is a blend of building and leading, not one or the other.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Mentor and coach developers, with particular focus on senior engineers, through code review, design discussions, and technical guidance.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Partner closely with Product and Operations to ensure technical solutions align with business needs and day-to-day operational realities.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Influence engineering culture and product solutions — within the team and company-wide — through thought leadership.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Drive full lifecycle application development: research technical options for new features, provide guidance based on findings, and build proofs of concept to validate the best approach.</span></li> </ul> <p style="color: !important;">&nbsp;</p> <h3><strong>What We're Looking For:</strong></h3> <p style="color: !important;"><span style="color: #0f6e5c;"><strong>Required</strong>&nbsp;</span></p> <ul> <li><span style="color: #1c2333;">Demonstrated agentic AI-first approach to the SDLC, with hands-on fluency in AI coding-agent tools such as Cursor, Claude Code, or VS Code with GitHub Copilot.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Knowledge and experience in AI agent development using tools and frameworks such as LangChain/LangGraph, Databricks, vector databases, and open- and closed-weight LLMs.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Broad AI-first mindset — comfortable evaluating and adopting new AI tooling and practices and coaching other engineers to do the same.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Bachelor's or master's degree in computer science, Computer Engineering, or a related field — or equivalent practical experience — plus 10+ years of .NET software development experience building web-based applications.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Strong knowledge of the Microsoft development stack: .NET Core, C#, JavaScript, RESTful services, ORM, T-SQL, JSON, MVC, XML, HTML, and CSS.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Strong design and architecture mindset, with experience designing scalable, high-performance, secure enterprise applications in Azure (or another public cloud).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Proficiency in modern engineering practices: unit testing, CI/CD pipelines, DevOps, microservices, and containerization (Docker/Kubernetes).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Deep knowledge of sound coding practices — unit testing, object-oriented design, and design patterns.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Comprehensive knowledge of databases (RDBMS and NoSQL) and advanced SQL, including stored procedures, indexes, functions, and triggers.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Experience with event-driven and messaging architectures (e.g., Kafka, Azure Service Bus, or Event Grid).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Thorough knowledge of source control (Git) in continuous integration environments.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Hands-on experience with Agile processes (Scrum/Kanban).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Experience with observability/monitoring tooling (e.g., Datadog, Application Insights, OpenTelemetry).</span></li> </ul> <ul> <li><span style="color: #1c2333;">Strong written and verbal communication skills, with a demonstrated ability to influence technical direction across teams and communicate with non-technical stakeholders.</span></li> </ul> <p style="color: !important;"><span style="color: #5b6472;"><strong>Preferred</strong></span></p> <ul> <li><span style="color: #1c2333;">Experience in payments, fintech, or financial services, including familiarity with compliance frameworks such as PCI-DSS.</span></li> </ul> <ul> <li><span style="color: #1c2333;">Prior experience mentoring senior engineers or acting as a technical lead without formal management authority.</span></li> </ul><div class="content-conclusion"><p>&nbsp;</p> <p><strong>About AvidXchange<br></strong></p> <p style="line-height: 28px;">AvidXchange is a leading provider of accounts payable (“AP”) automation software and payment solutions for middle-market businesses and their suppliers. By trade, we are a technology company, but if you ask anyone who works here, they’ll tell you our people are at the core of who we are. At AvidXchange, <strong>mindset is everything</strong>. We are <strong>Connected </strong><strong>as People</strong>, <strong>Growth Minded</strong>, and <strong>Customer Obsessed</strong>. These three mindsets represent our culture – who we are, who we’ve always been, and they guide us to improve every day. Since our founding in 2000 in Charlotte, NC, we’ve created a company of over 1,300 teammates working across the U.S., or remotely. AvidXchange is proud to be Certified™ as a <a href="[link no portal] target="_blank">Great</a> <a href="[link no portal] target="_blank">Place to Work</a>®. The prestigious recognition is based on anonymous data from our teammates and makes official what our teammates have known for years – that AvidXchange is a Great Place to Work®.&nbsp;</p> <p><strong>Who you are:</strong>&nbsp;</p> <ul type="disc"> <li style="line-height: 28px;">A go-getter with an entrepreneurial mindset – that means&nbsp;you are&nbsp;not afraid of taking risks,&nbsp;winning big&nbsp;or&nbsp;facing the unknown.&nbsp;</li> <li style="line-height: 28px;">Someone who understands that business is&nbsp;people centric. Connecting with others as humans first allows you to develop mutually beneficial working relationships.&nbsp;</li> <li style="line-height: 28px;">Focused on&nbsp;making a difference for our customers. AvidXchange exists to help solve complex problems for our customers so we can all realize our potential.&nbsp;</li> </ul> <p><strong>What you’ll get:</strong> &nbsp;</p> <p style="line-height: 28px;">AvidXchange teammates (we call them AvidXers) get the perks and prestige of a growing tech company paired with the flexibility of a founder-led startup. We help our AvidXers develop as professionals and as human beings, providing work/life balance, development programs, and competitive benefits. At AvidXchange, we are building more than a tech company – we are building an experience. We remain committed to a culture where you can fully be 'you’ – connected with others, chasing big goals, and making a meaningful impact. If you want to help us grow while realizing your potential and creating stories you’ll tell for years, you’ve come to the right place.</p> <p><strong>AvidXers enjoy:</strong>&nbsp;&nbsp;</p> <ul type="disc"> <li style="line-height: 28px;">18 days PTO*&nbsp;</li> <li style="line-height: 28px;">11 Holidays (8&nbsp;company&nbsp;recognized &amp; 3&nbsp;floating&nbsp;holidays)&nbsp;</li> <li style="line-height: 28px;">16 hours per year of&nbsp;paid Volunteer Time Off (VTO)&nbsp;</li> <li style="line-height: 28px;">Competitive Healthcare&nbsp;</li> <ul type="circle"> <li style="line-height: 28px;">High Deductible Heath Plan Option that has $0 monthly premium for teammate-only coverage&nbsp;</li> <li style="line-height: 28px;">Dental Base Plan Coverage</li> <li style="line-height: 28px;">100% AvidXchange paid Life Insurance&nbsp;</l