Industries
Forex first, ISP alongside, and the businesses around both. The engineering is the same each time. What changes is which problems appear first, which integrations matter, and which mistakes are expensive.
The chain from registration to first trade decides how the business performs. Every hour a document sits unreviewed is an hour a funded client is not trading.
Money moving between systems leaves no room for approximate answers. Records have to reconcile, and every state change has to be explainable afterwards.
Growth turns manual work into a crisis. Provisioning, billing and suspension all have to agree with each other, every day, without someone checking by hand.
The first version has to be small enough to ship and sound enough to build on. Most of our advice at this stage is about what to leave out.
Usually there is already a system, and it half works. Replacing everything is rarely the answer. Connecting what exists and automating the worst of the manual work usually is.
Control matters as much as capability: who has access, where data sits, how a change is approved, and what happens when a key person is unavailable.