The hard problems — an invitation

Here are the toughest open problems, stated without spin — because this is precisely where a contributor's work changes the trajectory of the whole project. Read them as seven invitations.

1. Cross-region atomic execution — no trustless solution yet; today, mitigation + economic underwriting (containment).
2. DA at GB/s with genuinely decentralized sampling — nobody has proven it.
3. Prover supply and the energy of large-scale proving — a heavy, unsolved cost.
4. Whether gravity-based placement converges to low cross-chain traffic — an unproven hypothesis.
5. The Asset Registry as a critical trusted component — it has to be rock-solid.
6. Keeping the Global Root minimal so it never becomes a governance bottleneck.
7. Relayer/watcher economics — an incentive model that keeps liveness guaranteed.

The honest ask: XChain doesn't need to be perfect today. It needs to point the right way, stay honest about the path, and ship working pieces on a steady beat. If any of these seven make your hands itch — that's the sign. Come build.