Founding Engineer
Summary
Founding full-stack engineer (leaning ML) at an early-stage fintech startup building an AI 'Finance OS' whose agents run accounts receivable end to end. You'd own the product surface and agent layer — Java, Python, TypeScript, LLMs — compensated with 0.5–5% equity until the seed round closes.
Compensation: 0.5% – 5.0%
ABOUT HYPERLOOP
We're building the Finance OS for the office of the CFO. Our agents run accounts receivable end to end — chasing invoices, answering payer questions, resolving disputes, applying cash. Autonomously, in production today, against real ledgers.
Enterprise, mid-market and self-serve, on one platform. Live with paying customers on signed annual contracts.
THE ROLE
Founding Engineer. Full-stack, leaning hard into ML. You'd own the product surface and the agent layer underneath it, with real authority over the architecture and where it goes next.
WHY WE NEED YOU
You've probably been the person on your team who actually understands how the system behaves in production — not just how it was designed. You've shipped ML into something real, watched it degrade in ways the offline metrics didn't predict, and built the tooling to catch that next time.
You're tired of having the interesting architectural decisions made two levels above you. You'd rather own a hard problem end to end, with the authority to decide how it gets solved, than optimise a slice of someone else's.
THE HARD PROBLEMS
Agents that run for months, not minutes. Durable state, replanning, idempotency, recovery. No framework does this.
Credit assignment on sparse, delayed, confounded outcomes — and the offline eval to ship against it, because you can't A/B against real money.
Autonomy with hard guarantees. Actions hit a real ledger. "Probably right" isn't available.
Plus the usual, done properly: multi-tenant isolation, high-throughput reconciliation, exactly-once scheduling, flaky third-party APIs, inference cost and latency, observability that still answers questions six weeks later.
ALSO YOURS
Model strategy — what runs where, and the quality/cost/latency tradeoff per decision type.
Deep integration with systems of record — not just reading, but acting in them safely and reversibly, to a standard an auditor accepts.
The product itself — onboarding, dashboards, the control plane that makes a team willing to switch autonomy on.
Plus the founding-engineer tax: CI, observability, on-call, the security questionnaire that unblocks a deal.
WHAT WE'RE LOOKING FOR
Strong Java and Python, plus real ML engineering experience. Backend discipline alongside the ability to train, evaluate and ship models that survive production.
No fixed years requirement — but we'll want referenceable experience, not a reading list.
You've shipped production systems and owned them afterwards.
ML and LLM work beyond prompting: fine-tuning, evals, retrieval, agent orchestration, or the cost/latency tradeoffs that decide what's viable.
Comfortable owning product surface as well as models, and comfortable being the one who decides.
Helpful, not required: fintech, accounting or ERP domain experience; a prior founding-engineer role; financial-grade correctness and audit requirements; anything public that shows you ship.
THE STACK
Java, Python and TypeScript. Anthropic API alongside open-weight models. DigitalOcean, GitHub, Google Workspace. Integrations into NetSuite, Business Central, Sage Intacct and QuickBooks. Slack is a first-class surface, not a notification channel.
You'd have real influence over what this becomes — several of these decisions are still open.
HIRING PROCESS
Two steps. No take-home marathon, no LeetCode.
Intro call with the founder. What you've built, what you want to own, how the comp structure lands for you.
Solve a real problem — one session, a problem from our actual domain. Use whatever you like, including Claude Code, Cursor or any other agent. We care how you think and how you use the tools.
COMPENSATION
Founder-level equity, 0.5–5%, vesting on a standard schedule from your start date.
No cash salary until our seed round closes, at which point the role converts to salary.
WHEN YOU APPLY
Tell us about something you built that you're proud of and what was hard about it, point us at a repo or demo, and say what you'd want to own first.
No cover letter. We reply within 72 hours either way.
