Staff Software Engineer, Ledger

Alt Platform Inc•New York, NY

3d•$300,000 - $500,000•Remote

About The Position

Alt is unlocking the value of alternative assets, starting with the $5 B trading-card market. We let collectors buy, sell, vault, and finance their cards in one place and we are backed by leaders at Stripe, Coinbase, Seven Seven Six, and pro athletes like Tom Brady and Giannis Antetokounmpo. Our next frontier is real-time pricing at scale—the Alt Value that powers every trade, loan, and product on the platform. THE NORTH STAR 99.99% reliability on gateway and banking integrations, and a ledger where every cent is accounted for and every entry says who created it and when. Supporting KPIs: reconciliation exception queue depth at daily close, gateway and banking integration uptime at 99.99%, P90 time from auction close to seller funds available, share of ACH returns and reversals handled with no manual correcting entry, and time to bring a new PSP or rail to production. TH ROLE: This is a builder's seat, not a manager's seat. You will write the ledger, the rails, and the reconciliation yourself. You will make the build-versus-buy call and defend it. You will tell the business no when correctness demands it, and you will be right often enough that they keep asking. The people who are great at this have owned a ledger somewhere it mattered, and they think in idempotency, race conditions, and reconciliation.

Requirements

Owned a double-entry ledger in production (built, migrated, or been accountable for one).
Moved real money on real rails (ACH origination and returns, RTP or FedNow, wires, or equivalent).
Experience with NACHA return windows and the impact of credit-push rails.
Experience handling large transactions where failure has immediate, significant financial consequences.
Database mastery: Expert SQL and relational design.
Experience with transactions that hold under load during peak times (e.g., auction close, auto-pay batches).
Proficiency in Python, Postgres, and AWS.
API-native understanding of webhooks, idempotency, eventual consistency, and reconciliation.
Built real things with AI (agents, skills, MCP servers, connectors, internal tooling).
Product-owner thinking: understanding fund flows and customer communication.
Restraint in avoiding overengineering; knowing when a simpler solution is appropriate.
Five to ten years of experience (though this is a guideline, not a strict requirement).

Nice To Haves

Enough React and TypeScript to ship customer-facing surfaces that read off the ledger.
Backgrounds in payments or ledger infrastructure at a pre-IPO fintech.
Experience with core banking or money movement at a marketplace.
Experience as a founding or early engineer who built the money layer.
Experience as an infrastructure engineer who took ownership of financial correctness.
Distributed systems experience.
Credit or risk modeling experience.
Direct experience with Stripe, Plaid, Airwallex, PayPal, Modern Treasury, or Increase.
Experience evaluating or implementing a third-party ledger service (Modern Treasury, Fragment, Formance, TigerBeetle or similar).
Stablecoin or on-chain settlement experience.
KYC/KYB experience.
Bank partnership experience.
SOX and audit-readiness exposure.
Collecting trading cards or an understanding of the market's direction.

Responsibilities

Own the ledger as a system of record, including entries, lines, balances, holds, reversals, and their states (pending, posted, available, canceled, declined, reversed).
Ensure immutability and audit trail as design constraints.
Provide point-in-time balances to show customer account status on any past date.
Own rails and money movement, including ACH origination and returns, RTP and other instant rails, wires, cards, and stablecoin settlement.
Manage product consequences of credit-push rails.
Own reconciliation when the ledger and processor disagree, including automated matching, an exception queue, and breaks caught before customers find them.
Own payouts and lending infrastructure, focusing on getting sellers and borrowers their money faster than competitors.
Manage the full loan lifecycle, from disbursement through repayment, partial payment, delinquency, and collateral release.
Manage risk posture on high-value flows, including setting holds, limits, and settlement windows with data and understanding their conversion cost.
Implement step-up verification triggered by risk signals.
Make trade-off calls between shipping speed and correctness, and build versus buy decisions.
Set the planning cadence with the hiring manager.
Work across Finance, Risk, Ops, and Support.
Explain upward why a number moved.

Benefits

Medical, dental, and vision insurance (company covers 85% for employees, up to 50% for dependents).
HSA/FSA available.
Generous PTO that employees are encouraged to take.
Parental leave at full salary.
$200/month wellness stipend.
$100/month home office stipend.
Free DoorDash Pass membership.
Remote-first work environment with WeWork access.
401(k).
Alt Equity for all full-time employees.