Arbitrum vs Optimism: five myths about Stylus Rust adoption

The shift toward Rust

Developers migrated away from Base as a 40% shift in programming preference favored Arbitrum. Arbitrum Stylus lets developers write in Rust or C/C++ and compile it to WebAssembly. This method eliminates the need to learn a domain-specific language. The code runs in a dedicated runtime alongside existing blockchain infrastructure. Because Stylus compiles Rust code into WebAssembly, developers can execute complex logic like iterative scoring or cryptographic functions at near-native speeds while paying significantly less gas than they would with traditional Solidity.

One myth claims developers must abandon their existing toolchains to build on Arbitrum. This is false because users keep their preferred crates and compilers. Another misconception states that onchain computation is too expensive for non-trivial logic. In a benchmark with 10 scoring factors and 50 refinement passes, Stylus used 90% less gas than an equivalent Solidity contract. RedStone ported its verification logic from Solidity to Stylus to achieve these savings. The scoring engine receives factor values and rule parameters as arrays, runs iterative scoring with cross-factor correlation, and then evaluates every pair of correlated factors through a series of decay calculations. The engine is stateless and stores nothing onchain. A third myth suggests that Rust code cannot interact with existing smart contracts. Stylus code operates alongside Solidity contracts and shares the same state. Developers use the abi module to encode and decode data between languages, which allows them to maintain existing workflows. The algorithm runs multiple passes over the rules to refine the score.

Efficiency and communication

A fourth myth claims that onchain logic can be silently modified after deployment. The blockchain ensures that the logic remains tamper-proof and deterministic. Developers use the stylus-sdk-rs library to manage storage and method exposure. The abi module transforms Solidity interface definitions into Rust structs and methods to ensure full compatibility. The call module manages interactions with external contracts by handling the execution context and providing mechanisms for standard and raw contract calls. This includes managing gas limits and call values. The deploy module facilitates the deployment of contracts on the Arbitrum network. The #[public] and #[entrypoint] macros manage the entry points for Stylus execution. Can developers scale their applications without increasing gas costs?

The stylus-sdk-rs library provides storage-backed Rust types that map to EVM storage slots. This ensures that the storage layout remains identical to Solidity counterparts. One myth posits that using new languages creates data silos. However, the blockchain handles the trust layer and ensures all execution is publicly verifiable. The call module allows for safe execution during re-entrant calls. The deploy module facilitates the deployment of contracts on the Arbitrum network. The #[public] and #[entrypoint] macros manage the entry points for Stylus execution.

Ecosystem scaling

Arbitrum leads the market with $17 billion in TVL as of mid-2026. Optimism remains smaller than Arbitrum on standalone TVL, sitting at $4 billion. Arbitrum has 999 monthly active developers compared to 637 on Optimism. Base holds 46% of all L2 DeFi TVL. Optimism relies on the OP Stack and the Superchain, while Arbitrum uses Nitro and Orbit.

Arbitrum is the stronger single DeFi venue because of its liquidity depth. Optimism is a broader infrastructure bet for those choosing a chain stack. The Nitro upgrade increased Arbitrum’s throughput by 7-10x compared to its level during the Odyssey campaign. Base has reached $10 billion in TVL and functions as a consumer-facing L2. Optimism distributed 215m OP tokens during its first airdrop to 250k addresses. Ethereum saw one million lifetime developer contributors in June 2026. Developers use Arbitrum for complex DeFi while Base handles consumer-facing products. You should focus on liquidity when choosing a chain for DeFi.