What a sequencer does
A rollup sequencer may collect user transactions, order them, and submit batches or data to a base chain. A fast confirmation in an interface does not necessarily mean the transaction has settled on the base chain or become irreversible. Sequencer design and guarantees differ, so consult the specific rollup’s documentation.
Inclusion versus settlement
If a sequencer stops, transaction submission, displayed balances, or withdrawal requests may be delayed. Check whether users can submit directly to the base chain, what delay and cost apply, and how censorship or reordering is handled during an outage. Upgrade and pause authority matters where operations are concentrated.
User impact during downtime
Incident notices should give start and end times, affected chain state, treatment of pending transactions, retry steps, and evidence relevant to funds. A transaction displayed as failed may still have been posted on the base chain, so compare its hash with an official explorer. Distinguish sequencer downtime from a base-chain outage.
A hypothetical outage
Suppose a hypothetical rollup interface shows success while batch publication is delayed. Before resubmitting, a user should check the account nonce, rollup explorer, and base-chain posting data. Repeated submission can create duplicate execution or additional fees.
Forced-exit paths
Record the sequencer replacement process, outage-detection criteria, forced-inclusion contract, and applicable delay from technical documentation. An incident postmortem is useful when it offers a reproducible timeline and specific preventive changes rather than only a statement of regret.
Check authority and incident notices
A documented plan for decentralized sequencing or exits does not by itself prove that the feature is active or practical in production. Check implementation status, costs, upgrade keys, and base-chain congestion. A rollup may use a base chain for security while retaining operational risks of its own.