Lambda functions default to the x86\_64 architecture, which is more expensive than Arm64. For many workloads, especially those written in interpreted languages (e.g., Python, Node.js) or compiled to architecture-neutral bytecode (e.g., Java), there is no dependency on x86-specific binaries. In such cases, moving to Arm64 can reduce compute costs by 20% without impacting functionality. Despite this, many teams continue to run Lambda functions on x86\_64 due to legacy configurations, inertia, or lack of awareness. This leads to avoidable spending, particularly at scale or in high-volume environments.
Lambda is billed based on: * Number of requests * Duration of execution (in milliseconds) * Memory allocated * CPU architecture (Arm64 functions cost **up to 20% less** than x86\_64)
