Staff Software Engineer - Ledger

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.

WHAT YOU'LL OWN:

• The ledger as system of record. Entries, lines, balances, holds, reversals, and the states between: pending, posted, available, canceled, declined, reversed. Immutability and audit trail as design constraints, not features. Point-in-time balances that show a customer where they stood on any past date. Done looks like an auditor pulling a trial balance without asking you for help.

• Rails and money movement. ACH origination and returns, RTP and other instant rails, wires, cards, and stablecoin settlement. A credit-push rail changes what you can auto-charge and when funds are final, and you own those product consequences, not just the integration. Done looks like the fourth PSP costing a sprint, not a rewrite.

• Reconciliation. When the ledger and the processor disagree, you own the answer. Automated matching, an exception queue a human can actually work, and breaks caught before a customer finds them. Every point of automation here is a point on the north star.

• Payouts and lending infrastructure. Getting sellers and borrowers their money faster than anyone else in this market: instant payout options, batch payouts at auction close, and the settlement timing that makes them safe. Then the full loan lifecycle, disbursement through repayment, partial payment, delinquency, and collateral release.

• Risk posture on high-value flows. Holds, limits, and settlement windows set with data, and you will know what each one costs in conversion. Step-up verification triggered by risk signals rather than blanket friction.

• The trade-off calls. Shipping speed against uncompromising correctness, build against buy. You set the planning cadence with Robbe, you work across Finance, Risk, Ops, and Support, and you are the one who explains upward why a number moved.

WHAT GREAT LOOKS LIKE IN 6 MONTHS:

• The reconciliation automation rate is materially higher than the day you started, and you can show the weekly series.

• The exception queue at daily close is worked to zero by a human in under an hour, on a system you built for that.

• A new rail or PSP has gone to production on the provider architecture you designed, and it did not require a ledger migration.

• Pending, posted, and available are modeled cleanly enough that Support answers "where is my money" off the customer-facing surface instead of escalating to engineering.

• Corrections post as reversing entries. Nobody has edited history, and an auditor can say so.

• At least one thing you shipped is running with AI in the loop, and the team depends on it.

• Finance trusts the close.

HOW YOU'LL USE AI HERE

• Turn a payment provider or bank partner integration spec into a typed client and a test suite in an afternoon instead of a sprint, including the ACH return codes and reversal paths nobody wants to hand-write.

• Stand up a rail simulator that produces the failures a sandbox won't: a late return, a duplicate callback, a partial reversal, a webhook that arrives twice out of order, a settlement that lands after the window closed. Then run your ledger against it.

• Build an agent that triages the reconciliation exception queue overnight, clusters the breaks, and hands you a ranked list with a proposed cause for each instead of a wall of unmatched rows.

• Put an MCP server over the ledger so "where did this discrepancy come from" is a question you ask in plain language rather than another one-off query against a table nobody else understands.

• Generate adversarial test cases for the lending and settlement state machines: the repayment that lands mid-default, the partial payment that arrives after a write-off, the return that hits after the payout cleared. Find the transitions nobody specified.

And have a view on the other side of it: what should not be handed to a model in financial code, and why. We ask.

If you've built agents, written skills or MCP servers, wired up connectors, or shipped internal tooling your team actually depends on, lead with that. Name the artifact, not the tool.

WHAT YOU BRING

• You have owned a double-entry ledger in production. Built one, migrated one, or been the person accountable for one. You can explain a modeling decision you would make differently now, and why.

• You have moved real money on real rails. ACH origination and returns, RTP or FedNow, wires, or equivalent. You know what an R01 is, why NACHA return windows matter, and why a credit-push rail changes the product flow and not just the API call.

• You have handled large transactions, where the failure mode is a five- or six-figure problem and somebody notices immediately.

• Database mastery. Expert SQL and relational design, and a transaction that holds under load at auction close and during scheduled auto-pay batches. Python, Postgres, and AWS are our stack.

• You're API-native. Webhooks, idempotency, eventual consistency, and reconciliation are your default vocabulary, not terms you looked up.

• You've built real things with AI, not just used it. Agents, skills, MCP servers, connectors, internal tooling people depend on.

• Product-owner thinking. You don't just build a pay button. You understand the flow of funds and how to tell a worried customer what happened to their money.

• Restraint. The most common way this seat fails is overengineering. You know when a queue and a lambda are the answer and when they are three new partial-failure modes.

We read the work, not the years. Most people who clear this bar have five to ten years behind them, and we have no interest in screening out the person who got there faster.

Strong plus: enough React and TypeScript to ship the customer-facing surface that reads off your ledger. This is not a fullstack seat, but the person who can take a ledger change all the way to the UI will go further here.

Backgrounds that fit: payments or ledger infrastructure at a pre-IPO fintech, core banking or money movement at a marketplace, a founding or early engineer who built the money layer, or an infrastructure engineer who took ownership of financial correctness because nobody else would.

Bonus: distributed systems, credit or risk modeling, direct experience with Stripe, Plaid, Airwallex, PayPal, Modern Treasury, or Increase, evaluating or implementing a third-party ledger service (Modern Treasury, Fragment, Formance, TigerBeetle or similar), stablecoin or on-chain settlement, KYC/KYB, bank partnership, or SOX and audit-readiness exposure. You collect, or you have a view on where this market is going.

US-based, remote.

HOW WE'LL INTERVIEW YOU:

We'll be specific so you can prepare. Before any of it: download the app, put a card up, make a bid, and try selling. Every round assumes you've used the product, and we expect your point of view to sharpen as you go. For this role, look specifically at the cash advance, deposit, and payout surfaces.

1. Recruiter screen, 25 minutes, Google Meet. The metric you own today and how you're performing against it, why Alt specifically, and how you're actually using AI. We align on comp here and answer your questions.

2. Hiring manager, Robbe Simon, 45 minutes, Google Meet.

3. Culture interview, 30 minutes. How you work with the people who depend on your systems: operations, finance, support, and the customer on the other end of a held transfer.

4. Technical screen, 60 minutes.

5. Architecture and system design, 60 minutes.

6. Leore, our founder and CEO, 30 minutes. Everyone who joins Alt meets Leore. Come with a point of view on where you'd take Alt's ledger and money movement first.

7. Reference check(s), 15 minutes, with a former manager.

Compensation: $200,000 - $500,000 per year, plus equity for all full-time employees.

What we offer:

For full-time Employees

• We cover 85% of your medical, dental, and vision, and up to 50% for dependents. HSA/FSA available

• Generous PTO that people actually take

• Parental leave at full salary

• $200/month wellness + $100/month home office stipend

• Free DoorDash Pass membership, because dinner shouldn't be a decision

• Remote-first (for most positions), with WeWork access when you want a room with other humans

• 401(k)

• Alt Equity to all full-time employees