Scroll zkEVM efficiency and Polygon AggLayer expansion

Scroll operates a centralized sequencer and a team-run prover network, while Polygon focuses on the AggLayer to unify its CDK chains. My verdict favors Scroll for developers needing immediate, specialized zkEVM environments, but Polygon’s modular stack wins for those requiring massive, interoperable scaling via the AggLayer.

Scroll prioritizes ZK technology over sequencer decentralization

Scroll uses a three-layer architecture consisting of a settlement layer, a sequencing layer, and a proving layer. The settlement layer uses Ethereum to provide data availability and ordering, the sequencing layer uses an execution node and a rollup node to produce blocks, and the proving layer uses a coordinator to dispatch tasks to a pool of provers. This design allows Scroll to batch transactions and generate proofs that verify legitimacy on Ethereum. Scroll’s zkEVM uses a modified version of ZCash’s "Halo2" code to use SNARKs without a trusted setup.

The sequencer handles the real-time critical tasks of transaction ordering, block building, and batch posting. In the Scroll network, the sequencer processes transactions from the L2 mempool and the L1 bridge contract to construct L2 blocks. The rollup node then monitors these blocks and submits a "Commit Transaction" to the rollup contract on Ethereum for data availability. Because Scroll runs a centralized sequencer, it faces the same liveness and censorship risks as other major L2s. A single operator deciding transaction order creates risks of MEV extraction and liveness failure if the operator goes offline.

Scroll targets Type 2 zkEVM status to achieve full EVM-equivalence, which helps eliminate edge-case incompatibilities in complex DeFi contracts. The team holds a roadmap for both sequencer and prover decentralization, though they have no confirmed mainnet date for a fully decentralized sequencer. You should check if your specific smart contract requires the full bytecode compatibility of a Type 2 system before committing.

Polygon shifts focus to AggLayer and CDK chains

Polygon moved away from its original PoS sidechain focus to build a suite including Polygon zkEVM, Polygon CDK, and the AggLayer. The Polygon CDK lets teams launch custom ZK-powered chains that connect to the AggLayer by default. This AggLayer collects ZK validity proofs from multiple CDK chains and aggregates them into one combined proof for Ethereum. This aggregation reduces settlement costs for each chain as more members join the network.

The Polygon zkEVM is an EVM-equivalent rollup that uses SNARKs to verify STARK proofs. This combines the speed of STARK proofs with the compact size of SNARK proofs to reduce costs and latency. However, Polygon zkEVM faces a difficult reality. The project runs at an annual loss of over $1 million and faced silent discontinuation of development by 2025. Polygon’s team shifted focus to the AggLayer and PoS mainnet improvements because the zkEVM project failed to match operational costs with revenue.

Polygon CDK allows for the creation of private application chains and provides dedicated blockspace for specific applications. Users on CDK chains can use native gas tokens or customizable fee structures to maintain stable costs. The LXLY Bridge enables these chains to exchange assets with other blockchains.

The liveness problem across Ethereum L2s

Every major Ethereum L2 still runs a centralized sequencer in 2026. This single-operator model creates a single point of failure. If the sequencer goes down, the entire chain stops and DeFi protocols freeze. Real incidents prove these risks. Linea paused its sequencer in June 2024 following a $6.8 million loss from a Velocore DEX exploit. Base experienced a downtime event in February 2025 that halted the entire chain.

Decentralizing these sequencers is difficult because multi-operator systems add latency when operators must reach consensus on transaction order. Shared sequencer networks like Espresso Systems attempt to solve this. Espresso’s Mainnet 0 runs a permissioned set of 100 nodes using HotShot consensus. Espresso has processed over 20 million transactions and secures more than $300 million in total value. However, Astria, a leading competitor, shut down in December 2025 due to funding and adoption challenges.

Matter Labs is working on the Prividium roadmap to convert institutional interest into deployed chains. This includes the Cari Network, which uses a tokenized deposit network for five U.S. regional banks. The active pipeline for ZKsync exceeds 30 institutions. ZKsync also plans to decentralize its sequencer set using Espresso Systems in its 2025 roadmap.

Comparative efficiency and deployment paths

The choice between Scroll and Polygon depends on whether a developer needs a single, highly optimized ZK environment or a connected ecosystem of custom chains. Scroll’s focus on the ZK hardware-optimized design and Halo2 proves its commitment to high-performance ZK execution. Its roadmap aims for a Type 2 zkEVM to provide a seamless developer experience for those migrating from Ethereum.

Polygon’s strength lies in the AggLayer, which uses ZK math to allow chains to communicate without traditional bridges. This architecture avoids the need for multisig operators or optimistic challengers. Users on CDK chains get access to dedicated blockspace, which protects their experience from the network activity of other chains.

The economic models differ significantly. Scroll relies on its ZK architecture to drive efficiency. Polygon uses the AggLayer to lower per-chain settlement costs as the number of connected chains grows. If a developer needs to launch an application-specific chain with its own gas token and regulatory compliance settings, Polygon CDK provides those tools through Zeeve or manual configuration. Will the AggLayer eventually consolidate enough liquidity to displace the established Optimism Superchain?