Scalability remains a significant barrier to the widespread adoption of blockchain systems in business. Permissioned blockchain systems often utilize clustering techniques to enhance scalability. Using clustering, nodes are organized into fault-tolerant clusters, with each cluster responsible for processing a distinct set of transactions. To improve scalability, permissioned blockchain systems implement either single-ledger or sharded-ledger approaches. The single-ledger approach involves replicating the entire ledger across all clusters, requiring every node to execute each transaction. In contrast, the sharded-ledger approach partitions the ledger into multiple shards, which are managed by different clusters. Sharded-ledger permissioned blockchain systems handle two types of transactions: intra-shard and cross-shard transactions. Cross-shard transactions can be processed through either a centralized method using a coordinator-based approach or a decentralized method employing a flattened approach. In this chapter, we present SharPer, a scalable permissioned blockchain system designed to accommodate networks comprising either crash-only or Byzantine nodes. SharPer implements flattened protocols to achieve cross-shard consensus effectively.