Software Engineer - Payments

At MAI (pronounced “my”), we're on a mission to democratize advanced advertising technology. We believe that cutting-edge marketing tools, once exclusive to large enterprises with massive budgets, should be accessible to everyone. Our platform uses AI agents to automate and optimize performance marketing, empowering small and mid-sized businesses to scale their ad spend profitably without the need for an agency or endless hours of manual campaign management.

Founded by ad platform veterans from Google and Instacart, we've successfully raised a $25 million Seed funding round led by Kleiner Perkins to accelerate our growth. This capital will be used to expand our product and engineering teams, bringing our vision of intelligent, autonomous marketing to life. Our AI agents have already proven their value, helping clients drive 40% more sales and managing millions in monthly Google Ads spend. Our client waitlist is growing by the day.

We are looking for a Payments Engineer to design and build a flexible billing platform that supports complex commercial models beyond Stripe’s out-of-the-box capabilities. You won’t just be "connecting APIs"—you’ll be the architect of a system designed to handle the hairiest commercial models in the industry.

You will own the payments architecture, from mastering the bridge between Stripe and Shopify Pay to engineering the intricate logic behind usage and token-based billing. If it involves the flow of money and the logic that powers it, you own it.

Design and build a flexible pricing engine that supports:

• Hybrid SaaS + usage-based pricing (tokens, executions, events).

• Tiered pricing, multi-phase lifecycle pricing, and promotions.

• Spend caps, guardrails, and custom contract logic.

• Enable rapid iteration on pricing without requiring constant code changes.

Own deep integration with Stripe and Shopify:

• Subscriptions, invoices, checkout, webhooks, tax, and payment flows, retries, failures, proration, refunds, disputes.

• Build reliable webhook and event-driven architecture (at-least-once delivery safe).

• Build high-reliability usage metering pipelines tied to product events.

• Design reconciliation systems to ensure:

  • Billing accuracy

  • Explainable invoices

• Implement internal ledger-like systems or audit layers where needed.

• Build tools for invoice review and overrides.

• Partner with Finance, Product, and Ops to ensure billing is transparent.

• 3–6+ years backend/software engineering experience.

• Hands-on experience with Stripe (subscriptions, billing, webhooks) in production.

• Experience building or owning billing, payments, or pricing systems.

• Strong understanding of:

  • Event-driven systems

  • Idempotency and retry safety

  • Data consistency and reconciliation

• Solid SQL/data skills (you can debug billing with data, not guesses).

Bonus points for experience in any of the following:

• Experience with usage-based or token-based billing systems.

• Experience integrating with Stripe and Shopify APIs or similar platforms.

• Familiarity with financial concepts:

  • Ledgering

  • Revenue recognition

  • Tax / VAT basics

• Experience building internal tooling for finance or operations.

• Unparalleled Learning: You'll be at the forefront of AI engineering, solving novel challenges in building scalable, reliable systems for autonomous agents and LLMs.

• High Impact: As an early member of a lean and powerful team, your work will directly shape our core platform, our culture, and the success of our customers.

• A Culture of Curiosity: We're a tight-knit team of passionate builders who value transparency, first-principles thinking, and a relentless drive to solve hard problems together.

• True Ownership: We believe in empowering our team. You'll have significant autonomy over your work and a clear path for growth as the company scales.

We're offering a stake in our success and a commitment to your well-being. Our total compensation package is designed to support you, both professionally and personally:

• Salary: Depending on your years of experience, a base salary range of $160,000 to $225,000.

• Equity: We want you to feel invested in our mission, which is why we offer meaningful equity.

• Health and Wellness: Our medical, dental and vision coverage is designed to take care of you and your family.

• 401(k): We'll help you build for your future with a competitive 401(k) program.

Are you ready to build the future with us? We believe in a holistic approach to hiring. If you're passionate about our mission and have a drive to learn and grow, we encourage you to apply even if you don't meet every single requirement. We value potential, curiosity, and hunger. We can't wait to hear from you.