# Senior Software Engineer, Ledger at Alt

- Company: Alt
- What the company does: Backed by First Round Capital.
- Company website: https://onlyalt.com
- Type: Startups
- Level: Senior
- Location: Remote
- Work setup: Remote
- Pay: $200K to $220K base salary per year (USD)
- Posted: 2026-08-26
- Apply by: 2026-10-14
- Apply: https://jobs.ashbyhq.com/alt/75af2a4b-143f-4e08-b35e-dda706f3a713
- Page: https://www.1752.vc/careers/jobs/alt-senior-software-engineer-ledger/

## About the role

A collector borrows against a card they own. We size the advance, disburse it, hold the collateral, and manage the loan for however long it runs. Meanwhile an auction closes and hundreds of payouts go out at once, each against a different fee schedule — some by ACH, some by wire, some instant. Every one of those movements has to land in a double-entry ledger that still balances at the end of the day.

## What they're looking for

- 5+ years of experience with a heavy focus on backend systems — Python, Postgres, AWS
- You've worked on real money movement. 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've worked with a double-entry ledger. Built one, migrated one, or owned one in production — and you can explain a modeling decision you'd make differently now
- You've handled large transactions , where the failure mode is a five- or six-figure problem and someone notices immediately
- Database mastery. Expert SQL and relational design. You know how to write a transaction that won't fail under load — including at auction close and during scheduled auto-pay batches
- You're API-native. Webhooks, idempotency, eventual consistency, and reconciliation are your default vocabulary

Tags: Product and Data