Workers IO
Workers IO is a YC Fall 2026 (F26) company. Based in San Francisco, CA, USA. Team of 2.
About Workers IO
Summary
Workers IO builds simulation environments that verify mission-critical software by running systems across millions of interleavings, fault conditions, and timing variations to surface the exact scenarios that break correctness guarantees. It targets engineering teams where high availability is a hard requirement, replacing manual testing and ad-hoc fault injection with exhaustive, automated verification. The product does the work of finding edge cases that conventional test suites miss.
Go-to-market
Engineering teams at companies operating mission-critical infrastructure are the primary buyers, reached through developer-led adoption.
From the Y Combinator listing
Simulation environments for verifying mission-critical software
Workers IO is building simulation environments to catch failures in mission-critical software before they reach production. We run your entire system through millions of simulated production scenarios to verify its correctness and performance properties. Coding agents can now generate code faster than teams can review it. Meanwhile, software and the infrastructure it runs on keep getting more complex. Tests check a small set of cases in isolation, in environments that are different from production. Some of the most expensive failures only surface when customers encounter them. We run your entire system unmodified and simulate network faults, disk failures, crashes, and clock drift. We build the fault models for you and check your system’s requirements across millions of scenarios. Every failure we find can be perfectly reproduced.
Facts
- B2B / B2B -> Engineering, Product and Design
- San Francisco, CA, USA
- 2
- Active
- Early
Founders (1)
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