Coasts

Localhost service isolation and orchestration for git worktrees

Y CombinatorFall 2025ActiveB2BEngineering, Product and DesignDeveloper ToolsB2BProductivityDesign

What they do

Problem

Developers and parallel AI coding agents running multiple git worktrees on one machine face conflicts like clashing ports, duplicated databases, and brittle per-branch setup.

Solution

Coasts provides containerized, per-worktree isolated local development runtimes that orchestrate services so each branch can run independently on the same host.

Who it's for

Software developers and teams using git worktrees and AI coding agents for parallel local development.

Founders

Jamie Sunderland

Founder/CEO

Second time YC founder. Former YC Product Engineer (I made the YC investor CRM). I like weird front end things a lot. In a former life I started Cheqout (YC W21), a QR-based ordering platform that grew to over 250 restaurants and $30M GMV during the pandemic. Before that I was a developer on Airbnb's China Risk Team.

Dan Hyman

Founder/CTO

Senior Engineer and Cloud/AWS expert with experience leading teams building enterprise applications and infrastructure. In a past life, I was a chef at a James Beard award winning restaurant.