Title: Staff Engineer (Agentic Payment)
Location: Remote-first (US preferred)
We have a presence in San Francisco and welcome in-person collaboration, but it is not required.
Role Type: Full-time, Founding Team Member
Compensation: Highly competitive base salary + significant early-stage equity
About AIsa
Backed by top-tier VCs, we are building the transaction backbone of the Agent Economy.
In the near future, billions of AI agents will autonomously interact, collaborate, and transact in the digital world. This will give rise to a new, trillion-dollar economy—the Agent Economy. However, the existing financial infrastructure was designed for humans; it is slow, rigid, and full of friction. Payments and settlements have become the biggest bottleneck hindering the explosion of the Agent Economy.
This is exactly why AIsa was born. We are an early-stage startup dedicated to building payment and billing infrastructure natively designed for AI agents. Our mission is to make the flow of value between machines as instantaneous, secure, and ubiquitous as the flow of information.
Here, you will not face bloated processes or heavy legacy code. You will join a lean, world-class engineering team. We are heavy users of AI tools (Claude Code, Cursor), and we advocate for rapid delivery, pragmatic decision-making, and a strong engineering culture. We are currently seeking a highly experienced backend engineer with a deep understanding of payment systems to join us as a core member of the founding team. Together, we will build the financial foundation of the next-generation digital economy from zero to one.
The Opportunity
As one of our early core engineers, you will have outsized ownership in leading the design and implementation of AIsa's core Metering/Billing and Ledger systems. You will tackle extremely high-concurrency event streams, ensure financial-grade data accuracy, and solve complex distributed system challenges.
This is a completely greenfield opportunity. Many of the use cases we are solving for did not exist a year ago. You will not just be writing code; you will be making critical architectural decisions, defining business logic, and making pragmatic trade-offs between technology and product delivery.
What You Will Do
•Architect the Metering & Billing Engine: Build high-throughput data pipelines capable of handling millions of concurrent events per day (1M+ events/day), ensuring strict idempotency, deduplication, and 99.9%+ accuracy in usage-based billing.
•Design the Core Ledger: Architect a robust financial ledger based on double-entry accounting principles. You will handle multi-currency balances, resolve race conditions, and manage isolation levels in high-concurrency transactions.
•Drive Integration & Reconciliation: Integrate with external payment gateways (e.g., Stripe, Adyen) and establish bulletproof daily automated reconciliation mechanisms to quickly identify and resolve financial discrepancies.
•Shape the Technical Foundation: Lead the evolution of our event-driven architecture, optimizing system performance and ensuring high availability under extreme conditions.
•Build and Ship: Spend 20%-40% of your time producing high-quality production code while also participating in technology selection and guiding the long-term technical roadmap.
What We Are Looking For
We are looking for builders who thrive in ambiguity and have a deep passion for financial infrastructure.
•Experience: 8-12+ years of backend software engineering experience, currently operating at a Senior or Staff Engineer level, and actively writing production code.
•Domain Expertise: You have led or deeply participated in building core Metering/Usage-based Billing systems or Financial Ledgers from zero to one, handling real money transactions at scale.
•Distributed Systems Mastery: Deep experience in event-driven architecture design. You are proficient in handling idempotency, deduplication, and high-throughput data processing.
•Database & Transaction Rigor: Expert understanding of ACID transaction properties and isolation levels. You know exactly how to handle concurrent balance updates and why high-precision data types (like Decimal) are mandatory in financial systems.
•Startup Mindset: You have a bias for action. You can make pragmatic technical decisions with incomplete information and are willing to find the balance between an MVP and a perfect architecture rather than over-engineering.
•Vision Alignment: You possess a strong belief in the Agent Economy, recognize the critical role of payment infrastructure within it, and are highly motivated by equity upside.
Bonus Points If You Have:
•Previous experience at payment infrastructure companies (e.g., Stripe, Square, Adyen), fintech platforms (e.g., Coinbase), or cloud service providers with massive usage-based billing scale.
•Familiarity with the internal mechanisms of mainstream payment gateways like Stripe.
•Experience with multi-currency processing, crypto/stablecoin payments, or clearing/settlement networks.
•A habit of heavily utilizing AI-assisted coding tools in your daily development workflow.
If you've built payment rails at Stripe, scaled billing engines at AWS or Twilio, designed ledgers at Coinbase or Block, or shipped financial infrastructure at companies like Adyen, PayPal, Wise, Plaid, Robinhood, Brex, Marqeta, Modern Treasury, Circle, Ripple, Bridge, Datadog, Snowflake, Metronome, or Chargebee — we'd love to talk to you.
What We Offer
•Founding Team Equity: Highly competitive early-stage equity that allows you to truly share in the massive upside of the company's growth.
•Zero Legacy Code: Experience the fulfillment of building mission-critical systems from zero to one and defining the standards for the next generation of payment infrastructure.
•Top-Tier Talent: Work alongside exceptionally talented engineers in a fast-paced, pragmatic, and challenging environment.
•Comprehensive Benefits: We offer a competitive package including health, dental, and vision insurance, flexible PTO, and wellness stipends (specifics vary by location).
At AIsa, we welcome diverse perspectives and people who think rigorously and aren't afraid to challenge assumptions. You're encouraged to apply even if your experience doesn't precisely match every bullet point in the job description.
Join us in building the future.