Freelance Ruby On Rails Startup Jobs in Arizona (NOW HIRING)

Location: San Francisco, CA or Phoenix, AZ (In-Office)

Partnership: EQL Tech has been exclusively retained by a high-growth technology startup to appoint a mission-critical Infrastructure Engineer to own the brand feel of the company and the movement they're building.

EQL Tech is proud to represent a highly ambitious, well-funded startup that has raised $16M from top-tier VCs and angels. The company is building the financial rails to help families access new State education funds (known as ESAs or School Choice Funds).

The $900B US Public Education budget is being opened up for parents to take control of their portion, which averages $7.5k per kid per year. Ambitious homeschool parents are already using these funds to piece together their dream education experience. Helping them access these funds is Step 1 in the journey to build the next-gen education system. The company treats this as their life's work and has already rejected an acquisition offer because they care about this being done right.

You will be joining an in-person company, working together in the office.

• The Founders: The founders are engineers who have run their own alternative school together. One previously worked as a Quant at Goldman Sachs, and the other built the computer vision system for the largest smart warehousing company globally, serving 1M customers/day at age 19.

• The Core Team: You will work alongside top talent, including a founding engineer who did AI research at MILA and at Elon Musk's SpaceX school, a Head of Risk from Mercury, Stripe, and Circle, and a Payments Engineer from Microsoft and Goldman Sachs. The team also includes the former Deputy Director at Arizona's ESA department and leading school choice advocates.

As Infrastructure Engineer, you will own every dollar that moves through Pathfinder's stack - from card issuing to disbursements, reconciliation, and regulatory reporting. You will work directly alongside the co-founders to build the technical backbone the company's mission depends on.

As Infrastructure Engineer, you will:

• Design a money movement flow: ledgered internal state, transaction lifecycle management, idempotency, retries, and deterministic replay so we can reason about every flow.
• Build high-trust, reliable reconciliation: daily/continuous reconciliation between internal ledger, card network events, banking events, and vendor/provider reports - and the tooling to investigate mismatches fast.
• Minimize operational risk: build guardrails that prevent bad states (double-spend, duplicate webhook processing, inconsistent balances, orphaned settlements).
• Payment Systems Architecture: Own and evolve a multi-service monorepo spanning an event-driven pipeline, a payments API (onboarding, credit, cards), balance healthchecks, and regulatory reporting jobs. Make architecture-level decisions on how to securely and reliably handle billions of dollars in state-funded educational payments, including card issuing infrastructure, processor integrations, and fraud and credit risk controls.
• Ledger Integrity Reconciliation: Be responsible for keeping independent ledgers aligned at all times despite asynchronous event processing. You can spot a missing cent and get to the root before errors compound. You will build and improve automated healthcheck and reconciliation systems that catch discrepancies the moment they appear, not the next morning.

Requirements

• Obsessive About Correctness: You know that a missing cent compounds into a crisis. Retries don't erase history, idempotency is deliberate, and validation belongs where truth lives - the database. You can spot a discrepancy before it becomes a problem.
• Assumes the Real World is Unreliable: Banks go down, queues back up, vendors change APIs without warning. You build systems that stay predictable anyway - "reliable" to you means consistent behaviour at 10 payments or 10,000,000.
• Craves Ownership: You want to be the single person everyone trusts when money is moving. You're not looking to contribute to a system - you want to have engineered it so that emergencies are rare and recoverable when they happen.
• High-Auditability Mindset: You're willing to go deep on a single missing transaction and trace it through every layer of the stack. You build tooling that lets you and your team investigate mismatches fast, not the next morning.
• Able to work in-person with the team in San Francisco, CA or Phoenix, AZ (visa support available)
• Experience with Lithic, Column, LoanPro, Stripe Issuing, or comparable card and banking infrastructure is a strong plus

Benefits

This will be a big commitment, and we're aiming high. It needs to be something you are energised about taking on, or this isn't the team for you.

• Competitive Salary: $125,000 - $175,000 per year, commensurate with experience.
• Generous Founding Equity: We compensate you well with equity.
• Top-Tier Backing: We've raised $16M from top-tier VCs and angels.
• Relocation Support: You are willing to relocate to San Francisco, CA, or Phoenix, AZ, and travel to visit customers. We're an in-person company and are in the office together.
• Comprehensive Visa Sponsorship: If you do not have a visa, we can support you.
• Unmatched Impact: The rare opportunity to directly shape how the $900B US Public Education budget is being opened up for parents to take control of their portion (avg. $7.5k/kid/year).