Expert: Interactive Coding, Payments Processing (Contract, Remote)

Patronus AI, Inc.

1d • Remote

About The Position

Patronus AI is hiring an independent contractor to work remotely with its research team on interactive coding scenarios in a sandboxed payments codebase. In live screen-share sessions, the contractor will implement or review changes, explain their reasoning, identify where scenarios do not reflect real money movement, and help define correct outcomes. Each session begins with a provided scenario and concludes with a short asynchronous write-up. The work contributes evaluation and training data for frontier AI models.

The role focuses on payment processing and gateway integration, ledger, settlement and reconciliation, or disputes, risk and compliance engineering. Applicants should apply under the area that best matches their work. The engagement is fully remote, available in any country with a few hours of overlap with US or EU working hours, and involves about 10 hours per week for an initial 1 to 3 months, with possible extension for strong performers. Pay is $150 per hour, including for the paid trial session, and the start date is rolling.

Solutions, notes, and reviews must be the contractor's own work; LLM-generated code or text is not permitted. Scenarios must be original, and no code, configuration, or transaction data from current or former employers or clients, or anything covered by an NDA, may be used. Quality is judged on correctness, clarity of reasoning, and reviewer agreement rather than speed or volume.

Requirements

• At least 3 years writing production code for a payment processor, processor integration, card issuer or acquirer, fintech ledger, or bank payments platform, including relevant work within the last two years; the candidate must have written code personally, as team management alone is insufficient.
• Working command of the end-to-end money-movement lifecycle, including authorization, capture, settlement, reconciliation, and disputes, as well as compliance topics such as PCI DSS and SCA.
• Comfort with at least one of Python, Go, Java, or TypeScript, and ability to read unfamiliar codebases.
• Ability to explain reasoning aloud while working in clear professional English.
• Reliable availability for scheduled live sessions and a habit of showing evidence behind conclusions.
• All solutions, write-ups, and reviews must be original work; LLM-generated code or text is not permitted.
• Do not use code, configuration, or transaction data from current or former employers or clients, or material covered by an NDA.

Nice To Haves

• Experience with multiple processors or payment rails, such as Stripe, Adyen, card networks, ACH, SEPA, or UPI.
• Experience writing technical design documents, incident reviews, or interview questions for payments systems.
• Familiarity with how AI coding agents fail on payments work.

Responsibilities

• Implement and review payment flows live with a researcher in a sandboxed codebase, including authorization, capture and refund paths, idempotent retries, webhook handlers, ledger entries, reconciliation jobs, and dispute handling.
• Explain reasoning while working, including the edge cases checked.
• Review drafted scenarios for realism and difficulty, and identify real-world failure modes such as double charges, partial captures, currency rounding, race conditions, and stale or replayed webhooks.
• Help write acceptance criteria for scenarios, including tempting incorrect approaches.
• Write short notes after each session describing the approach and what was verified.
• Incorporate reviewer feedback within agreed turnaround times and flag guideline gaps or encountered edge cases.

What This Job Offers

• Career Level: Senior
• Education Level: No Education Listed