Running Rollups in Production: What Breaks

A single sequencer is a single point of failure. It can front-run, censor, or go offline, breaking liveness guarantees and user trust.

• Risk: Centralized sequencers like Optimism and Arbitrum can halt the chain.
• Solution: Move to decentralized sequencer sets or shared sequencing layers like Espresso Systems or Astria.
• Metric: Downtime of a single sequencer can halt $10B+ TVL.

Publishing data to Ethereum is the primary operational cost. As L1 gas prices spike, your rollup becomes unusably expensive.

• Problem: Celestia and EigenDA offer cheaper DA, but introduce new security/trust assumptions.
• Trade-off: Choosing cheap DA sacrifices Ethereum's security for -90% cost reduction.
• Reality: This is the core economic battle between zkSync, Starknet, and Arbitrum Nova.

ZK-Rollups hit a computational ceiling. Generating proofs for large blocks creates unbearable latency, capping TPS.

• Bottleneck: zkEVM proofs can take ~10 minutes, making real-time settlement impossible.
• Solution: Parallel provers, custom hardware (Accseal, Cysic), and proof aggregation.
• Outcome: Without innovation, ZK-rollups remain slower and more expensive than Optimistic counterparts.

The centralized sequencer is a massive, often ignored, liveness risk. When it goes down, your chain halts. This isn't theoretical; Arbitrum, Optimism, and Base have all experienced multi-hour outages.

• Key Risk: Your L2 is a permissioned chain until decentralization.
• Key Mitigation: Implement a robust, multi-validator sequencer set with fast failover, or plan for Espresso Systems or Astria shared sequencing.

Unbounded state growth is a silent killer. A full archive node for a mature rollup can require >10 TB of storage, making node operation prohibitively expensive and centralizing infrastructure.

• Key Problem: High hardware costs lead to fewer nodes, reducing censorship resistance.
• Key Solution: Mandate state expiry (like zkSync) or implement stateless clients and Verkle trees from day one.

If your data availability (DA) layer fails or becomes prohibitively expensive, your rollup's security collapses to a multisig. Celestia, EigenDA, and Avail are not just cost plays; they are liveness guarantees.

• Key Insight: Cheapest DA often means highest risk during congestion.
• Key Action: Model cost/security trade-offs under >1000 TPS and >$200 gas on Ethereum L1.

A spike in transaction volume can create a massive proving backlog, stalling bridge withdrawals for hours. This destroys user trust and is a primary vector for CEX vs. DEX arbitrage attacks.

• Key Failure Mode: Throughput is gated by your prover's peak capacity, not its average.
• Key Fix: Over-provision prover infrastructure with 3-5x headroom and implement priority proving lanes for withdrawals.

The multisig controlling your upgradeable bridge and rollup contracts is the ultimate attack vector. Polygon, Optimism, and Arbitrum all hold billions via 4/8 or similar multisigs.

• Key Reality: You are running an L1 with a centralized governance model.
• Key Protocol: Enforce strict timelocks, delegate calls, and plan a credible path to immutable contracts or robust DAO governance.

Ignoring MEV in your sequencer design is subsidizing sophisticated bots at the expense of your users. It leads to network instability and toxic flow.

• Key Truth: A naive FCFS sequencer is a public MEV extraction engine.
• Key Architecture: Integrate a SUAVE-like block builder, or adopt a PBS (Proposer-Builder Separation) model from the start, as seen in Flashbots research.