Open source startup MetalBear raises $12.5M for mirrord, a Kubernetes tool that lets developers test local code directly in the cloud and slash development cycles by up to 98%.
MetalBear, a Tel Aviv-based startup, has raised $12.5 million in seed funding to expand its open-source Kubernetes tool mirrord, designed to radically reduce enterprise software testing and deployment bottlenecks. The round was led by TLV Partners, with participation from TQ Ventures, MTF, and Netz Capital, alongside angel investors David Cramer (Sentry co-founder) and Ben Sigelman (OpenTelemetry co-creator).
mirrord enables developers to run local code directly against live cloud environments without deployment, providing guardrails such as traffic routing, queue splitting, and side-effect isolation to ensure safe testing. Reported benefits include up to 98% faster development cycles, 80% quicker test iterations, and a 30% reduction in production bugs. In one case, customer CoLab cut cycle times from 15 minutes to 10 seconds.
Adoption spans from independent developers to Fortune 100 companies, with teams at Nvidia, AWS, and Apple among users. While the open-source edition offers direct local-to-cloud loops, the enterprise version adds permissions and controls for teams working at scale.
Eyal Bukchin, CTO and co-founder, said: “With microservice architectures, it’s very difficult to run the one or two services you’re working on in the context of the larger application. Enterprises can have hundreds or thousands of services, and running the whole thing locally is often impossible.” He added: “AI is accelerating code generation, reviews, and unit tests, but integration testing isn’t solved by AI. The queue just gets longer because all that new code still has to be tested in context.”
Aviram Hassan, CEO and co-founder, explained: “We let engineers isolate their change in a running ‘plane,’ see how it behaves, and only then go through the full verification. You still do the steps; you just move the long loop later.”
Named a Gartner Cool Vendor in Container Management, MetalBear is positioning mirrord as a core enabler of faster, safer software workflows that bridge the gap between local development and cloud deployment.
