The system architecture of Linea consists of three governance and operational tiers: the execution layer, the proof layer, and the protocol governance layer. These three tiers together form the source of Linea's long-term stability, and the key lies in very clear authority boundaries, preventing governance complexity from spiraling out of control as the scale expands.
In the execution layer, the Sequencer is responsible for transaction ordering and block construction. At this stage, a centralized sorter is used for efficiency, but the roadmap clearly indicates that the sorting power will gradually be decentralized to multiple nodes in the future. The autonomy of the sorting layer is not a one-time delegation, but rather a phased approach: starting with permissioned nodes and gradually opening up to a permissionless sorting network. This 'progressive decentralization' can avoid instability in the early execution layer due to uneven node quality, while also laying the foundation for long-term resistance to censorship.
At the proof layer, Linea's zkEVM is the core of the entire governance structure. The proof system does not accept human intervention; it automatically generates proofs based on execution trajectories, with the Aggregator responsible for compression, which is then verified by Ethereum. This structure allows the verification authority to be naturally structured as 'math-dominated', rather than 'node-dominated'. The governance layer does not change the proof rules, but adjusts circuit versions, verification cost models, and aggregation batch logic through parameterization. The high degree of autonomy of the proof layer reduces collaboration costs and prevents governance from falling into frequent interventions in micro-parameters.
The protocol governance layer is responsible for structural specifications, rather than execution details. The content established by the governance layer includes the decentralization path of the sequencer, the upgrade process of verification parameters, DA submission rules, oracle compliance, and the protocol's revenue distribution model. The principle of governance boundary convergence is very clear: governance does not participate in execution sorting, does not participate in proof generation, does not participate in individual contract operations, and is only responsible for the rules of the system mechanism itself.
This governance convergence allows Linea to maintain stability as it scales. As applications grow, more users join, and on-chain load increases, the complexity of governance does not rise linearly, because governance does not need to manage every subsystem, but only needs to maintain the stability of structural rules.
Risk structures are also decomposed by layers. The risks at the execution layer come from the sequencers, but the permissions of the sorting layer are limited, and they do not participate in state verification, therefore they do not threaten the entire system. The proof layer takes on the verification responsibility; as long as the zk proof is correct, risks at the execution layer are isolated. The data layer is responsible for DA, so the recoverability and finality of the state are provided by Layer1, which has the highest level of fault tolerance. Risks at the governance layer arise from parameter changes, but all parameter changes have a delay mechanism, on-chain transparent records, and multi-stage proposal processes, making risks controllable.
Lineas coordination mechanism relies on 'cross-layer verification paths'. The execution layer submits transaction batches, the proof layer generates proofs, the Aggregator aggregates, and finally submits for Ethereum verification. If the execution layer encounters abnormalities (for example, if the sequencer does not package according to rules), the proof layer will refuse to generate proofs due to inconsistent trajectories. The proof layer is the natural reviewer of the execution layer, and governance does not need to intervene in coordination. This layered error-correction structure gives the system self-stabilizing capabilities.
In terms of protocol upgrades, Linea has adopted a rigorous progressive upgrade mechanism. Any changes to zkEVM circuits, Aggregator logic, or Sequencer rules must first be simulated in a testing environment, then verified in a secondary network, and finally submitted to the mainnet governance. The upgrade process will not forcibly replace at a single point in time, but will be gradually enabled in multiple batches to prevent validation or execution failures caused by version switching. This engineering upgrade process is key to ensuring the long-term stability of zkEVM.
The economic structure is closely tied to the governance structure. Linea's fee distribution model revolves around two main lines: execution costs and proof costs. Sequencers receive part of the execution revenue, provers receive part of the proof subsidies, and the protocol fund is responsible for long-term support for circuit upgrades and system expansion. The voting rights of governors are designed to be distributed weights, not solely determined by the number of tokens, but in combination with staking duration, participation history, and verification contributions, aligning the interests of governance participants with system security.
In terms of ecological expansion, Linea's zkEVM provides consistent verification security, allowing applications such as DeFi, data computation, and identity systems to operate under the same verification standards. This uniformity reduces cross-application risks and means governance does not need to set special cases for specific fields. The larger the ecology, the more stable the structure, and the lower the governance cost, which is a 'reverse complexity' that Linea's engineering design deliberately pursues.
Overall, Linea's governance philosophy is not about 'expanding governance', but rather 'reducing governance', bringing the system into a state that is structurally predictable, parameter manageable, and verifiably reproducible. It executes layered governance, proves layers, and governs layers to prevent risk concentration; parameterized governance, progressive upgrades, and phased decentralization ensure that the system does not lose stability due to scale growth.
The value of Linea is not only to expand Ethereum but to make expansion a sustainable engineering system in the long term.
