Launching a token on one chain is a solved problem. Launching the same token across 7 chains at once, with liquidity and state that stay coherent, is not. Memetropolis, the OFT launchpad I founded on LayerZero, found that out the hard way during early testing, and the bug that surfaced is one almost every multi-chain team hits eventually.
The naive version of a launchpad backend signs transactions sequentially: fetch the current nonce for an address, build the transaction, sign it, send it, move to the next request. That works fine with one user. It works fine in a demo. It falls apart the moment two users hit the launchpad in the same second, because both requests fetch the same nonce before either transaction lands. One of the two signed transactions is now invalid the instant it reaches the mempool, and depending on timing, the result ranges from a failed transaction to funds that get stranded mid-flow across a chain boundary.
This is not a rare edge case at any real scale. At 5,000 users across 7 EVM chains, the same-second collision is not a hypothetical, it is Tuesday. "Works in the demo" and "works at 100 concurrent users" are different engineering problems, and the gap between them is exactly where projects that raised real money quietly die.
The fix that held for Memetropolis was not a fancier queue or a bigger server. It was three layers of correctness stacked together: Postgres advisory locks to serialize access to shared state at the database level, per-address chain locks so two requests for the same address on the same chain cannot race each other, and nonces that get fetched fresh at the moment of signing rather than cached anywhere upstream. None of these three alone fixes the problem. Together, they make the collision structurally impossible instead of merely unlikely.
The broader principle is one I apply to every system I build now, agentic or not: code that only works when requests arrive one at a time is not production code, no matter how clean the demo looks. Real usage is concurrent by default. If the concurrency story is not designed in from the start, it shows up later as stranded funds, corrupted state, or a support queue full of "where did my transaction go." Cheaper to solve it once, correctly, before the second user ever shows up.