Founding Engineer

San Francisco, CA (Onsite preferred)

XPay.sh

Full-time | Early Team | Equity Heavy

XPay.sh is building the financial infrastructure layer for the Agentic Economy.

We enable AI agents to:

• Charge per run
• Settle instantly
• Transact with other agents
• Operate under programmable guardrails
• Move money across USDC, USD, and global rails

From x402 payment triggers to native MCP, A2A, and pay-per-execution primitives were building machine-native payments infrastructure for the next generation of software.

If Stripe built for SaaS

XPay is building for autonomous agents.

Were hiring a Founding Engineer to help architect and build the core infrastructure powering agent-to-agent transactions, programmable wallets, and pay-per-run execution.

This is not a feature-factory role.

This is a 01 systems builder position.

Youll work directly with the founders to design, ship, and scale the primitives that power agentic commerce.

• Pay-Per-Run execution rails (x402 gateway)
• Programmable wallets with guardrails (spend limits, policy engine, identity)
• Agent payment SDKs (TypeScript + Python)
• n8n / workflow native payment nodes
• Stablecoin settlement (USDC rails + fiat off-ramps)
• Observability + transaction verification layer
• Risk & abuse prevention infrastructure

Youll touch backend infra, SDK design, developer experience, and protocol architecture.

(Current + Evolving)

• TypeScript / Node.js
• Python
• Postgres
• Redis
• Blockchain integrations (USDC, EVM rails)
• REST + Webhooks
• Docker / Cloud infrastructure
• Payment orchestration systems
• Workflow engines (n8n, automation tools)
• Event-driven architecture

Experience with payments, fintech, crypto rails, or distributed systems is highly valued.

• 5+ years building backend systems or fintech infrastructure
• Strong system design and architectural thinking
• Experience with APIs, SDK design, and developer tools
• Comfort in ambiguity and fast iteration cycles
• Experience in startups (01 product building)
• Bonus: crypto rails, stablecoins, policy engines, compliance-aware systems

Most importantly:

You think in primitives. Not features.

• Stable Pay-Per-Run architecture live
• Production-grade programmable wallet guardrails
• Clean developer SDK adoption
• <100ms trigger latency on payment flows
• Agents transacting autonomously using XPay rails

• Build foundational infrastructure for AI-native commerce
• Early equity in a category-defining company
• Work at the intersection of AI + fintech + programmable money
• High ownership, direct impact, no bureaucracy
• San Francisco network access + ecosystem proximity

• Competitive early-stage salary
• Meaningful founding equity
• Performance upside