Domain
Blockchain & Web3
Skill Profile
L2 solutions: Optimistic Rollups, ZK-Rollups, Sidechains, Polygon, Arbitrum
Roles
2
where this skill appears
Levels
5
structured growth path
Mandatory requirements
5
the other 5 optional
Blockchain & Web3
Blockchain Infrastructure
3/17/2026
Choose your current level and compare expectations. The items below show what to cover to advance to the next level.
The table shows how skill depth grows from Junior to Principal. Click a row to see details.
| Role | Required | Description |
|---|---|---|
| Blockchain Developer | Required | Understands L2 concepts: optimistic rollups (Optimism, Arbitrum) and zk-rollups (zkSync, StarkNet). Deploys L2 node on testnet and studies gas model and finality differences between L1 and L2. |
| Smart Contract Developer | Deploys contracts to L2 networks (Arbitrum, Optimism, zkSync). Understands differences in gas models and EVM compatibility. Tests on L2 testnets and compares deployment costs. |
| Role | Required | Description |
|---|---|---|
| Blockchain Developer | Required | Configures and operates L2 nodes in production. Implements cross-layer messaging infrastructure (L1<->L2). Understands fraud proofs, validity proofs, and sequencer architecture. |
| Smart Contract Developer | Adapts contracts for L2 deployment: accounts for L1-data costs in gas calculation, L2-specific precompiles. Implements L1↔L2 contract messaging for deposit/withdrawal flows. |
| Role | Required | Description |
|---|---|---|
| Blockchain Developer | Required | Designs multi-L2 infrastructure: shared sequencer, cross-L2 messaging, data availability layer. Optimizes calldata costs via EIP-4844 blob transactions. Analyzes sequencer centralization risks. |
| Smart Contract Developer | Designs cross-L2 contract architectures. Implements L2-native features and optimizes for L2-specific gas models. Analyzes security implications of sequencer centralization. |
| Role | Required | Description |
|---|---|---|
| Blockchain Developer | Required | Defines L2 infrastructure strategy for the organization. Evaluates appchain vs shared rollup approaches for various products. Establishes cross-chain interoperability standards. |
| Smart Contract Developer | Defines L2 deployment strategy for the organization. Selects L2 for various contract use cases. Establishes L2 compatibility testing requirements and deployment automation. |
| Role | Required | Description |
|---|---|---|
| Blockchain Developer | Required | Shapes enterprise vision of L2 scaling: L3, validium, volition approaches. Researches shared sequencing and based rollups. Publishes L2 infrastructure landscape analysis. |
| Smart Contract Developer | Defines enterprise L2 contract strategy. Researches appchains, L3, and custom execution environments. Shapes cross-L2 interoperability vision for smart contract platforms. |