Ermal Kaleci developed advanced cross-contract interoperability features for the paritytech/polkadot-sdk and paritytech/revive repositories, focusing on delegate_call enhancements. He implemented address-based delegate_call targeting with configurable resource limits, integrating these capabilities into the PolkA VM and updating runtime APIs, benchmarks, and test suites. Using Rust and Solidity, Ermal ensured that contracts could execute code from other contracts while preserving caller context, improving contract orchestration and resource safety. His work demonstrated depth in low-level programming and smart contract development, delivering robust, well-tested features that support faster rollouts and more flexible tooling within the Substrate and Wasm-based blockchain ecosystem.