Solidity Support: OP Stack vs ZK Stack

Optimistic Rollup with EVM Equivalence: Offers near-perfect compatibility with Ethereum tooling (Hardhat, Foundry, Ethers.js). This matters for teams prioritizing fast time-to-market and leveraging existing Solidity libraries. The ecosystem, led by Optimism Mainnet and Base, has over $6B TVL and thousands of deployed contracts.

Cost-effective for compute-heavy dApps: Transaction fees are primarily for state updates, not proof generation. This matters for high-frequency DeFi protocols (like Perpetuals on Synthetix) or social apps where user actions are complex but not latency-critical. Average fees are 80-90% lower than Ethereum L1.

Validity Proofs with instant L1 finality: State transitions are verified by cryptographic proofs, removing the 7-day fraud proof window risk. This matters for bridges, exchanges, and institutions requiring capital efficiency and strong security guarantees, as seen with zkSync Era's native AA and dYdX's migration.

Higher theoretical TPS and lower latency: Proof compression allows more transactions per batch. This matters for true mass-market applications like gaming or payment networks needing sub-second finality. zkEVMs like Polygon zkEVM and Scroll demonstrate ~2-5 second finality vs. Optimistic's ~12 minutes.

7-day challenge period for L1 withdrawals: Creates capital inefficiency for users and protocols. Relies on at least one honest actor to submit fraud proofs. This matters for CEX integration or applications where liquidity needs to be portable quickly.

Higher operational overhead for sequencers: Generating ZK proofs requires specialized, expensive hardware (GPUs/ASICs), potentially centralizing infrastructure. Solidity developers may face subtle VM differences (e.g., opcode support) requiring audits. This matters for self-deploying a chain (Layer 3) and controlling operational costs.

Full bytecode compatibility: Deploy existing Solidity contracts with zero modifications. This matters for teams migrating from Ethereum Mainnet or other EVM L2s like Arbitrum, minimizing audit overhead and migration risk.

Optimistic rollup tooling maturity: Leverage battle-tested frameworks like Foundry and Hardhat with native support. This matters for rapid prototyping and teams prioritizing time-to-market, as seen with Base and Zora's quick deployment cycles.

Validity proofs ensure state correctness: Each batch includes a SNARK/STARK proof verified on L1. This matters for DeFi protocols handling high-value assets where the 7-day fraud proof window of Optimistic Rollups is an unacceptable risk.

ZK-EVM architecture enables built-in AA: Supports paymasters and sponsored transactions at the protocol level. This matters for applications requiring superior UX (e.g., social dApps) and where lower latency finality is critical.

Single sequencer model is common: Most OP Stack chains (e.g., Base) use a centralized sequencer for speed, creating a liveness dependency. This matters for protocols requiring maximum censorship resistance and decentralized liveness guarantees.

ZK-circuits require specialized knowledge: Debugging failed proofs and optimizing for prover costs adds overhead. This matters for small teams without cryptographic expertise, as seen in the longer dev cycles for early zkSync Era and Scroll deployments.

Full EVM Equivalence: Supports the entire Solidity toolchain (Hardhat, Foundry, Ethers.js) with zero modifications. This matters for rapid deployment and leveraging existing codebases and developer knowledge.

Lower Fixed Costs & Faster Finality: No expensive ZK proof generation means lower base operating costs and 1-2 minute optimistic finality. This matters for general-purpose dApps where ultra-fast cryptographic finality is not a strict requirement.

Cryptographic Security Guarantees: State transitions are verified by validity proofs, providing Ethereum-level security and ~10-minute finality on L1. This matters for high-value DeFi, bridges, and institutional applications where trust minimization is paramount.

Superior Data Efficiency: Leverages ZK validity proofs and EIP-4844 blobs to minimize L1 data posting costs. This matters for high-throughput applications (e.g., gaming, social) where scaling transaction volume cost-effectively is critical.

Security Delay & Challenges: Relies on a 7-day fraud proof window, introducing a withdrawal delay and requiring active watchdogs. This is a non-starter for exchanges or protocols that require instant, provable finality for asset bridging.

Proving Complexity & Cost: Requires specialized ZK circuits and provers, increasing engineering complexity and creating higher fixed operational costs. This matters for smaller teams or MVPs where development speed and low overhead are priorities.