Senior Software Engineer [SaaS] PO→Payment

Company Description Vireo is an AI-powered procurement platform designed for mid-market companies, helping teams transform unstructured requests into clear, structured RFQs. The platform applies advanced quote ranking and risk scoring to support informed, due-diligence-backed purchasing decisions. Vireo streamlines the end-to-end procurement lifecycle, including purchase orders, goods receipt, quality checks, invoicing, and payment tracking. Built for both direct and indirect procurement, it is highly configurable to align with diverse business operations. Vireo focuses on intelligent, efficient workflows from initial request through to final payment. Role Description The Senior Software Engineer [SaaS] PO→Payment role is a full-time remote position responsible for building and maintaining core backend services that power Vireo’s purchase order-to-payment workflows. This role involves designing and implementing scalable, secure APIs, integrating with external financial and invoicing systems, and ensuring data integrity across procurement, goods receipt, and payment tracking modules. The engineer will collaborate closely with product, design, and data teams to translate business requirements into robust technical solutions, perform code reviews, and improve system performance and reliability. Daily work includes writing clean, well-tested code, troubleshooting production issues, optimizing existing features, and contributing to architectural decisions for Vireo’s SaaS platform. The role also includes mentoring teammates and promoting best practices in software engineering and cloud-native development. Own VireoSequence [PO → GR+QC → Invoice → Payment] + solidify VireoIntelligence parsing/ranking. Qualifications Must Have — What Vireo Actually Needs Strong foundation in Computer Science, practical algorithms, data structures, systems design for real product.Proficiency in Python, production-grade applications. Python is required. Vireo stack is Python + Flask/FastAPI + Supabase. Java/Go/Node is a plus, not a substitute.Hands-on Back-End Web Development — REST APIs, Postgres + Supabase [Row Level Security, multi-tenancy, migrations], database-driven applications. Knows how to model requests → rfqs → quotes → pos → receipts → invoices in one continuous record with zero re-typing.Experience building multi-tenant B2B SaaS — tenant isolation, subscription logic, audit trail, role-based access. Hands-on with cloud-based systems - Supabase / Vercel / AWS / GCP — deploys, monitors, secures. Comfortable lean stack, not heavy microservices.AI-Native Builder — integrates LLM APIs [Claude / GPT-4o] for Email-to-Structured RFQ and PDF/Excel parsing. Knows confidence scoring [0.00-1.00], low-confidence → Manual Review, never auto-ranked.Solid OOP + clean architecture reviewable PRs.Comfort with Git, CI/CD, automated testing, collaborative workflows merge. Senior review for PO→Payment is his job from Month 4.Strong problem-solving, clear async communication, self-directed in remote team Builds secure and reliable — understands 3-way match [PO-GR-Invoice], exception-only review, payment orchestration via licensed third-party gateway [Vireo does NOT move money itself], reconciliat Plus — Not Required But Huge Plus for Vire Prior B2B SaaS, procurement, or enterprise workflow platform — knows RFQ lifecycle, due diligence, or AP process.Experience with document parsing — LlamaParse, Unstructured, OCR for PDFs/Excel with threading/reference code.Experience with payment gateway orchestration and audit trail queryability.