Yehiel developed a downside-only rightsizing feature for the spotinst/openapi repository, focusing on API design and backend development using YAML. The work introduced a mechanism to restrict rightsizing recommendations to downscaling actions at both cluster and rule levels, reducing the risk of unintended upscaling. Yehiel updated API responses and schema definitions to enforce this policy, ensuring downstream tools and integrations adhere to the new constraint. The end-to-end implementation improved cost optimization and governance across environments by guiding users toward cost-aware decisions. The project demonstrated depth in backend systems and API schema evolution, though it was limited to a single feature.