📋 Sequencers: L2 Transaction Ordering
Learn how sequencers process and batch rollup transactions
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0 / 5 completed🎯 Sequencer Queue Mechanics
The sequencer queue is the heart of Layer 2 transaction processing. Understanding how transactions flow through this queue is crucial for optimizing L2 applications and anticipating MEV risks.
Single entity control
High transaction capacity
Average wait time
🔄 Transaction Flow Simulator
Watch how transactions move through the sequencer queue from submission to L1 finality. Each stage has unique characteristics and timing.
Transaction Submission
Users submit transactions to L2 sequencer endpoint
🏗️ What is a Sequencer?
Central Coordinator
The sequencer is responsible for receiving, ordering, and executing transactions on Layer 2. It acts as the transaction gatekeeper.
Fast Confirmation
Provides instant soft confirmation (~100ms) before L1 finality, enabling responsive user experiences.
Trust Assumption
Currently centralized in most L2s - users trust the sequencer to order fairly and not censor transactions.
✅ Advantages
- •Instant pre-confirmations for better UX
- •High throughput (2000+ TPS)
- •Efficient batch optimization reduces L1 costs
- •Simpler infrastructure and lower latency
⚠️ Risks
- •Single point of failure and censorship
- •MEV extraction opportunities for operator
- •Liveness depends on sequencer uptime
- •Trust in operator's fair ordering