Principal Software Engineer

About this role

Principal Engineer, Payments

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.

What You'll Do:

Technical Leadership & Architecture

• Define and drive the Payments platform's technical approach, system design decisions, and engineering best practices.

• 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.).

• Partner with Solution and Enterprise Architects, and with developers, to determine optimal designs for architecture, efficiency, maintainability, and scalability across new and existing capabilities.

• Collaborate with Product, Business Operations, and Engineering leaders to align technical solutions with business needs and shape engineering roadmaps.

AI-First Engineering

• 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.

• 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.

• Champion AI-driven engineering practices — intelligent automation, predictive analytics, and self-healing systems — to improve development efficiency and system resilience.

• Identify and implement AI-based solutions for Payments product initiatives, from proof of concept through production.

• Model and promote an AI-first mindset across the team — evaluating new AI tooling, sharing what works, and pushing the team toward higher leverage.

Quality, Security & Delivery

• 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).

• Own code quality and unit test coverage; partner with QA to design and review test cases so the platform meets customer expectations.

• Perform code reviews and approve pull requests, ensuring code follows documented standards and best practices.

• Own the health of the software delivery pipeline and guide the team in improving it.

Hands-On Development, Mentorship & Collaboration

• 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.

• Mentor and coach developers, with particular focus on senior engineers, through code review, design discussions, and technical guidance.

• Partner closely with Product and Operations to ensure technical solutions align with business needs and day-to-day operational realities.

• Influence engineering culture and product solutions — within the team and company-wide — through thought leadership.

• 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.

What We're Looking For:

Required

• 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.

• Knowledge and experience in AI agent development using tools and frameworks such as LangChain/LangGraph, Databricks, vector databases, and open- and closed-weight LLMs.

• Broad AI-first mindset — comfortable evaluating and adopting new AI tooling and practices and coaching other engineers to do the same.

• 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.

• Strong knowledge of the Microsoft development stack: .NET Core, C#, JavaScript, RESTful services, ORM, T-SQL, JSON, MVC, XML, HTML, and CSS.

• Strong design and architecture mindset, with experience designing scalable, high-performance, secure enterprise applications in Azure (or another public cloud).

• Proficiency in modern engineering practices: unit testing, CI/CD pipelines, DevOps, microservices, and containerization (Docker/Kubernetes).

• Deep knowledge of sound coding practices — unit testing, object-oriented design, and design patterns.

• Comprehensive knowledge of databases (RDBMS and NoSQL) and advanced SQL, including stored procedures, indexes, functions, and triggers.

• Experience with event-driven and messaging architectures (e.g., Kafka, Azure Service Bus, or Event Grid).

• Thorough knowledge of source control (Git) in continuous integration environments.

• Hands-on experience with Agile processes (Scrum/Kanban).

• Experience with observability/monitoring tooling (e.g., Datadog, Application Insights, OpenTelemetry).

• Strong written and verbal communication skills, with a demonstrated ability to influence technical direction across teams and communicate with non-technical stakeholders.

Preferred

• Experience in payments, fintech, or financial services, including familiarity with compliance frameworks such as PCI-DSS.

• Prior experience mentoring senior engineers or acting as a…