Sr. Software Engineer, Payments

Plug Technologies Inc•Los Angeles, CA

1d•$185,000 - $215,000•Onsite

About The Position

We are looking for a Sr. Software Engineer to own Plug's payment infrastructure - end to end and to work on other aspects of the business as well. You'll architect how money moves through our two-sided marketplace, primarily over ACH: dealers paying Plug for auction wins ($10K-$100K+ per transaction, averaging ~$25K), dealer floorplan financing, Plug paying consumers and consignors when we acquire their vehicle, and platform fee capture at settlement. You'll help with vendor selection, partner with the payments PM on KYC/KYB onboarding flow, design the reconciliation systems our Finance team depends on, and own the technical compliance posture for ACH processing at scale, partnering with the PM on regulatory and licensing requirements. You'll report to our head of engineering and work directly with our SVP Product & Technology and VP Finance as primary stakeholders. You'll work in close partnership with a payments PM, jointly owning Plug's payment rails: the PM owns financial logic, specs, and the finance relationship; you own implementation, infrastructure, and reliability.

Requirements

5+ years of hands-on experience developing and delivering production applications; 3+ years of payments experience.
Demonstrated experience implementing payment flows in production involving ACH/wire/real-time payments, marketplace split settlements, wallets, for benefit of (FBO) accounts, or platform payouts.
Understanding of ACH mechanics (return codes, NACHA authorization, account validation), and KYC/KYB processes (UBO identification, OFAC screening)
Demonstrated proficiency in TypeScript across the full stack - backend, frontend, PostgreSQL schema design for financial data, and API/webhook integrations.
Experience designing idempotent systems and working with double-entry ledger concepts - can speak to exactly-once semantics and reconciliation schema design.
Hands-on experience deploying and operating cloud-hosted applications; comfort with infrastructure-as-code (we use Terraform), CI/CD pipelines, and observability tooling.
Operates in agent-first development workflows - comfortable orchestrating multiple agents, defining clear acceptance criteria, and reviewing AI-generated output with a high quality bar.
Prior startup experience and a track record of owning work end-to-end: scoping, shipping, and measuring impact.
Authorized to work in the US for any employer.

Nice To Haves

Temporal or comparable durable workflow experience is a strong plus.

Responsibilities

Lead the technical design and implementation of Plug's payment solution across consumer and businesses: KYC / KYB onboarding, ACH pay-in and pay-out rails, card acceptance, platform fee capture, and settlement reconciliation.
Participate in the vendor selection process - evaluate solutions such as Stripe Connect, Modern Treasury. Possibly create PoC builds. Provide analysis documents.
Design, implement, test, debug, and document payment features ensuring correctness, idempotency, and auditability - where "mostly works" is not acceptable when money is moving.
Take ownership of features end-to-end, evaluating effort, risk, and priority in an agile environment with Finance and Product as key internal stakeholders.
Collaborate with colleagues and be a strong voice in product and architecture design sessions.
Use agentic coding tools to write clear, efficient, and scalable code with an eye toward flexibility and maintainability.
Own and contribute to team productivity and process improvements, including bringing payments domain knowledge to the broader team.
Actively raise the technical bar through thoughtful code review, pairing, and knowledge sharing - including how you use AI tools.