← Sequencer & Rollup Architecture — From Centralized Block Producer to Shared Sequencers

Building & Decentralization

Lesson 7 of 7·QUIZ12 min50 XP

Treat this page as a workbench, not a blog post. The goal is to extract a reusable mental model from the source and carry it into the rest of the Fabrknt stack.

Course

Sequencer & Rollup Architecture — From Centralized Block Producer to Shared Sequencers

Lesson role

QUIZ

Sequence

7 / 7

Quiz — Sequencer & Rollup Architecture

Question

Recap the six lessons: sequencer architecture, batch posting + DA, op-rbuilder internals, fraud proofs vs ZK proofs, minimal-sequencer build, decentralisation paths.

Principle (minimum model)

Sequencer recap. Three components (mempool + builder + batcher); centralised dominates; force-include via L1 preserves censorship resistance.
DA recap. Three strategies (L1 calldata / EIP-4844 blobs / alt-DA chains). Blobs ~90 % cheaper. DAS is the future.
Verification model recap. Fraud proofs (optimistic, 7-day window) vs ZK validity proofs (immediate finality, expensive prover).
Minimal-build recap. ~250 lines of Rust; mempool + builder (revm loop) + batcher + L1 inbox watcher.
Decentralisation recap. Shared sequencers (Espresso / Astria) + sequencer auctions (Aori); 12-36 months out; force-include is the 2026 compromise.

Worked example + steps

Final quiz: sequencer & rollup architecture

The L2 architect's final check. You'll need this to ship a rollup, integrate with Tempo's sequencer, or design a new L2.

Summary (3 lines)

Eight questions across all six lessons.
Get three or more wrong → re-read the relevant lesson before moving on.
Pass → Advanced sequencer track complete. Next: validator / p2p / cross-chain Advanced tracks, or Building OpenHL for the practical openhl Rust implementation.

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Lesson 6 — Decentralization paths — shared sequencers and MEV-aware auctions