MEV & Transaction Ordering

Every transaction you send sits for a few seconds in plain sight, in a mempool anyone can read, and whoever builds the next block decides not just which pending transactions go in but in what order. On a chain where a swap’s outcome depends on what came right before it, that ordering power isn’t a clerical detail — it’s money, with a name: Maximal Extractable Value (MEV), the dark matter of DeFi that’s invisible in the UI but enormous in aggregate.

This course builds the whole machine from the mempool up:

• What MEV is — why the right to order transactions has value at all, and why “just send the transaction” hides a billion-dollar war over sequencing.
• Mempool & ordering mechanism — how transactions are picked, and how priority fees turned ordering into a live auction.
• Front-running & back-running — getting in just ahead of or just behind a victim.
• The sandwich attack — the signature DeFi predator, worked out with exact constant-product math so you can compute the victim’s loss and the attacker’s profit yourself.
• Arbitrage & liquidations — the benign, load-bearing side of MEV that keeps prices aligned and lending markets solvent.
• Countermeasures — Proposer-Builder Separation, MEV-Boost, relays, private orderflow, fair ordering and encrypted mempools.

This sits at the top of the crypto ladder, assuming you already know how Ethereum orders and prices transactions and how an AMM walks a curve. By the end, “I made a swap” stops being a single click and becomes a transparent, adversarial pipeline you can reason about, price, and defend against.