Senior Software Engineer, Payments

About this role

Order.co is the System of Action for the Office of the CFO, transforming the way businesses purchase and pay into an intuitive, B2C-like shopping experience. Order.co leverages embedded AI agents and embedded financial products to reinvent the way businesses connect with their vendors.

End users enjoy a seamless, zero-training buying experience, while finance and procurement leaders gain a single platform to orchestrate how the business “should operate”. The result is an all-in-one solution that serves as a gravitational pull for spend and data, automating and eliminating procurement and finance workflows from requisition to reconciliation along the way.

Order.co is on the cutting edge of B2B Agentic Commerce, poised to be the market leader in creating a more predictive, prescriptive, and personalized experience for users.

Founded in 2016 and headquartered in New York City, Order.co oversees nearly half a billion in annualized spend across hundreds of customers like WeWork, SoulCycle, Lume, and [solidcore]. Order.co has raised $75M in funding from industry-leading investors like MIT, Stage 2 Capital, Rally Ventures, 645 Ventures, and more. Order.co has been proudly named a 50 to Watch by Spend Matters and a Best Place to Work by BuiltIn and Inc. Magazine.

The Role

As a Senior Software Engineer on the Payments team, you will own the software that moves real money for Order.co's customers — virtual-card issuance and authorization, bank connections, accounting integrations, recurring and consolidated invoicing, and ACH / RTP rails. You'll deliver complex features reliably, own subsystems end-to-end from initial design through rollout and post-release fixes, and mentor junior and mid-level engineers along the way. You'll be a credible technical voice in design discussions, challenge weak assumptions early, and help the team build software that is correct, maintainable, and secure — qualities that matter especially in code paths where a bug shows up on a customer's bank statement. Along the way, you'll grow your architectural judgment in money-movement systems and predictably ship work that moves the business forward.

Responsibilities

Technical Execution & Code Ownership

• Independently design and implement complex, multi-part features from requirements to production

• Own subsystems, services, or critical components in the payments stack — for example, the internal financial ledger, the virtual-cards issuance and authorization lifecycle, bank connections, or the invoicing and auto-debit pipeline. The team routes questions to you for these areas

• Write clean, maintainable, production-ready code with consistent test coverage — money-movement code paths are held to a high test bar

• Navigate existing codebases with architectural discernment — identify sound patterns to build upon, recognize technical debt, and use AI tooling as an accelerant while applying your own judgment on correctness, security, and alignment with the system's direction

• Debug production issues effectively; seek first to understand — investigate evidence and identify root causes rather than applying band-aids, especially in webhook, retry, and reconciliation paths where a quick patch can hide a deeper consistency bug

Design & Architecture Contribution

• Participate actively in design reviews; your designs regularly influence team-level architecture decisions

• Propose sound technical designs that account for scalability, performance, and reliability trade-offs — and for payments-specific concerns like idempotency, exactly-once semantics, reconciliation between internal state and vendor reports, and clean separation between authorization and capture

• Identify risks before they become incidents — surface edge cases, data consistency concerns, and failure modes during planning. In payments, that includes double-charge, double-credit, dropped webhook, and out-of-order event scenarios

End-to-End Delivery & Ownership

• Scope and estimate work accurately; solve problems in order — break down epics into deliverable, independently reviewable units

• Deliver features end-to-end, including rollout coordination and post-release monitoring. Rollouts that affect real money rely on feature-flagging, dark-launching, reconciling, and watching dashboards before declaring "done"

• Communicate risks and blockers early — don't absorb uncertainty silently

• Review stories critically before committing: ensure they're appropriately broken down and that dependencies are well understood by the team

Mentorship & Technical Leadership

• Mentor junior and mid-level engineers through code reviews, pairing, and direct feedback

• Provide high-quality, substantive code reviews — lead with humility, treat the author as a teammate to help, and catch what AI misses; teach others to do the same

• Teach best practices; your presence raises the quality of code around you

Technical Influence

• Influence technical decisions through credibility, not just seniority

• Drive improvements in team practices — testing patterns, observability for money-movement flows, code organization, and the bar for test coverage in code paths that move real funds

• Champion quality and standards; push back on shortcuts that create long-term cost — especially in code that touches funds or credit

Communication & Collaboration

• Explain technical decisions clearly to both technical and non-technical stakeholders

• Represent engineering well in product and cross-functional discussions, including with Finance, Operations, and Credit on reconciliation, credit-risk, and dispute-handling questions

• Translate vendor documentation (Stripe, Lithic, and others) into clear, scoped engineering work

• Approach all assignments with a security lens — actively look for vulnerabilities in your own code and in the code you review, with extra care in PII and PCI-adjacent paths

Qualifications

• You are motivated by accountability — you own outcomes, not just tasks

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