The RoleWe’re hiring a Senior Full Stack Engineer for the Accounting & Finance pod to extend the payment, billing, and invoicing experiences across our product suite, top to bottom. That covers Stripe Connect integrations, Client-native payment processing, hosted payment pages, ACH and eCheck in the US, PAD / ACSS debit in Canada, surcharging, recurring billing, payouts, trust accounting workflows, and reconciliation. You’ll also help migrate firms off legacy processors onto our unified payments gateway.You’ll move comfortably between React/Next.js and C# / .NET microservices, often in the same feature. One day you’re implementing Stripe Elements and 3D Secure UX in Next.js. The next day you’re designing the PaymentIntent webhook handler, idempotency model, and SQL Server schema that backs it.This is a hands-on senior IC role. You won’t manage people, but you’ll set the technical bar in the pod, mentor mid-level engineers through code review, and have real influence over architecture decisions across both stacks.What You’ll DoBuild and ship money-movement features end-to-end•      Architect and build full-stack payment features (UI, API, service logic, data model) for invoicing, billing, hosted payment pages, payment method management, recurring billing, refunds, payouts, and reconciliation.•      Implement Stripe Elements, Payment Element, Checkout, and 3DS / SCA on the front-end while owning the matching PaymentIntents, webhook handlers, and persistence on the back-end.•      Build idempotent, retry-safe, observable payment workflows on the back-end and surface their state correctly on the front-end. Webhook-driven UI, optimistic updates done responsibly.•      Get ledger correctness right. Trust accounting means gross settlement, strict trust vs operating fund segregation, correct refund and chargeback routing, and statement descriptors that hold up to audit. Every cent lands in the right bucket, every time.•      Build merchant onboarding and KYC flows using embedded Stripe Connect components, with webhook-driven account status transitions handled correctly.•      Ship behind feature flags and entitlement gating. New payment capabilities roll out by region, brand, and package tier, and your code has to respect all three.•      Own data model design and migrations in SQL Server (T-SQL, Entity Framework) for the finance schemas you build.•      Drive front-end performance for payment surfaces. Core Web Vitals, bundle size, time-to-interactive. Conversion depends on it.Modernize both stacks•      Help migrate legacy front-end code (jQuery, older React, mixed styling approaches) into a clean, component-based Next.js architecture.•      Contribute to ongoing decomposition of legacy monolith code into focused, well-bounded .NET microservices.•      Set the standard for API contract design between front-end and back-end. Versioned, RESTful, idempotent, with consistent error semantics.•      Make real architectural calls on both sides. State management and data fetching on the front. Service boundaries and async messaging on the back.Raise the engineering bar•      Run code reviews that teach, across both stacks. Lift the team’s overall skill level.•      Drive automated testing for money-movement flows. Unit, integration, contract tests at service boundaries, and e2e tests (Playwright or Cypress) on the front.•      Be a power user of Claude, Claude Code, GitHub Copilot, and our internal GPTs. Help others on the team get more out of these tools across both stacks.•      Keep architecture and runbook docs current. Payments operations need clear, accurate documentation when something breaks at 2am.What We’re Looking ForFront-end experience•      Strong production experience with React, including modern hooks, suspense, and patterns. Next.js preferred. Equivalent depth in Remix or similar is fine.•      Advanced TypeScript and modern JavaScript. You write code that other engineers can read, extend, and trust.•      Solid grounding in performance, accessibility (WCAG), responsive design, and component architecture.•      Experience with enterprise component libraries (MUI, Radix UI, Shadcn) and data-heavy UI is a plus.Back-end experience•      Strong production experience in .NET / C# (.NET 6/8 or later), building RESTful APIs and microservices following API-first principles.•      Strong knowledge of SQL Server, T-SQL, schema design, query performance tuning, and Entity Framework / ADO.NET.•      Experience with cloud platforms. AWS preferred (Lambda, ECS, RDS, SQS, S3, CloudWatch). Azure equivalents are fine.•      Architectural judgment on service boundaries, async messaging, caching, and consistency trade-offs.Full-stack bar•      5+ years of professional software engineering experience, with at least 2+ years of meaningful full-stack work. You’ve shipped features end-to-end, not just thrown code over the wall in either direction.•      Comfort being primary owner of a feature across both stacks. You don’t need a separate engineer to write the API for your UI or vice versa.Payments experience (strongly preferred)•      Hands-on Stripe integration in production. Embedded Checkout, Payment Element, and Connect onboarding components on the front. PaymentIntents, connected accounts, payment method cloning, refunds, and Connect webhooks on the back.•      Stripe Connect experience is a strong differentiator. Connected account creation, direct charges, KYC and persons, capability and requirements webhooks, and payout bank attachment.•      Deep understanding of idempotency, retry safety, webhook signature verification, replay protection, and the failure modes of distributed payment systems.•      Experience integrating multiple processors behind one gateway, or running processor migrations, is a strong plus. So is embedded payment page architecture (iframes, postMessage, hosted fields).•      Familiarity with PCI-aware patterns. Tokenization, hosted fields, never touching raw card data, and the SAQ implications of how you build.•      Comfort with the operational side of payments. Refunds, partial captures, 3DS / SCA, declined-card UX, ACH and eCheck, surcharging, disputes and chargebacks, payouts, and reconciliation.•      Exposure to merchant onboarding and KYC flows, ledgering systems, or trust accounting is a strong plus.•      Bonus: Stripe Connect, marketplace flows, multi-merchant architectures, or experience integrating a second payment processor alongside Stripe.Cross-functional and quality•      Experience with CI/CD pipelines (AWS CodePipeline, TeamCity, GitHub Actions, or similar) and automated testing as part of the development workflow.•      Strong communication. You can explain a technical trade-off to a product manager and a junior engineer with equal clarity.•      Track record of mentoring peers and owning delivery outcomes inside an Agile team.AI-augmented development•      You actively use Claude, Claude Code, GitHub Copilot, Cursor, or similar AI coding assistants in your daily workflow. You can show how they’ve made you faster and more effective on both stacks.•      Eagerness to push what AI tools can do for full-stack work. Code generation, refactoring, test scaffolding, schema design, debugging, design-to-code translation.•      Willingness to share what’s working with the broader engineering org and help raise the AI-fluency bar across pods.