Testing Layer 1 blockchains requires a different mindset—bugs can’t be patched post-deployment, and failures can be catastrophic. At 57Blocks, we developed a strategy for testing EVM and Cosmos-based L1s focusing on six key risks: immutability, financial exposure, systemic risks, boundary complexity, cryptoeconomic attacks, and adversarial conditions. Our framework includes functional testing of staking, slashing, and consensus; performance testing under load; and upgrade validation using rolling upgrades and Cosmovisor. We prioritize automation with GitHub Actions, TypeScript, Hardhat, and Mocha to replicate production behavior. CI/CD pipelines simulate failures in devnets and testnets to catch edge cases before reaching mainnet. Our approach emphasizes resilient infrastructure, automated deployments, and real-time monitoring. The goal isn’t just to prevent bugs but to ensure economic and systemic robustness. As the blockchain space matures, strong QA practices will differentiate successful chains. To support the ecosystem, we're launching ChainSmith, our open-source framework for stress-testing L1s in real-world conditions.