gap_01
The work here is co-build, and nobody is in the room.
One pan-African telco is collapsing a fragmented estate of apps into a single platform while re-platforming a mobile money business that spans 14 markets onto a mini-app architecture. Tier-one banks are modernising cores against regulatory deadlines. These are the same migration executed dozens of times with per-market variation, which is what long-running agents are good at and hand-rolled engineering is worst at. The reflex here is to add systems-integrator headcount, so cost scales linearly with every new market. Nobody is proposing the alternative.
what an FDE does
Pick one service, one market. Build the migration agent alongside their platform team: it reads the current API surface and the target contract, generates the adapter, backfills tests to the coverage gate, and opens a PR a human reviews. Encode what it cannot resolve as rules, so market N+1 costs less than market N. Their team owns it by the end.