What we're building

Enterprise marketing still runs through agencies because launching one campaign means coordinating specialists across Marketo, HubSpot, Meta, LinkedIn, CMSs, and a dozen other systems. It takes weeks.

CharacterQuilt uses computer-use agents to do that work inside the software companies already use. A campaign that took three months can now ship in two days. We raised $13M and were one of the fastest-growing companies in YC's P26 batch.

The role

You'll own the runtime behind every agent run: workers, sandboxes, files, skills, authenticated browsers, durable state, retries, recovery, and the API and CLI around the system.

You'll work directly with me and a very small engineering team. Our agents touch customer software and real budgets, so "probably worked" is not good enough.

What you'll do

• Provision and operate workers and sandboxes.
• Make file, skill, and workspace hydration fast and correct.
• Build reliable browser authentication and session isolation.
• Design retries, replay, cancellation, recovery, and observability.
• Ship the API, CLI, and MCP surfaces customers and our own agents use.

You might be a fit if

• You're a strong full-stack engineer who likes databases, distributed systems, filesystems, and browsers.
• You move quickly but care deeply about correctness.
• You want broad ownership at an early-stage company.

Five days a week in Union Square. $250K to $350K base plus 0.5% to 3% equity. We do not sponsor US visas.