Developed and delivered the CalcAmountIn feature for the KyberNetwork/kyberswap-dex-lib repository, enabling accurate calculation of input token amounts required to achieve a specific output across multiple liquidity sources. Focused on backend development using Go and JavaScript, the work included implementing inventory and limit checks to prevent over-swapping and robust error handling for insufficient liquidity. The feature was integrated into both the Kyber-pmm pool simulator and the Hashflow-v3 liquidity source, with comprehensive unit and integration tests to ensure correctness. This enhancement improved trade predictability, reduced slippage risk, and strengthened liquidity management within decentralized finance smart contract systems.