Each emirate has its own authority, and it matters
Property regulation is emirate-level, not federal. Dubai's Land Department and its regulatory arm govern registration, brokerage and escrow in Dubai. Abu Dhabi has its own department with its own system and its own rules. They are not interchangeable, and a product built around one emirate's process does not simply expand to the next.
For a software company this is a product decision as much as a legal one. Decide early whether you are building for one emirate deeply or building an abstraction that survives both, because retrofitting the second is expensive.
Selling to developers and brokerages
The buyers have budget and they are used to procurement. Expect a pilot, expect it to involve a named champion, and expect the decision to take a quarter or two. Price accordingly: a product that needs a six-month sale cannot be priced like a monthly tool.
The upside is that these customers stay. Switching costs in property software are high, contracts renew, and a product embedded in how a brokerage operates is not casually replaced. Slow to win, slow to lose.
Construction is a separate business from property
Founders conflate them and should not. Construction technology sells to contractors and consultants, and the problems are site progress, snagging, procurement and payment certification. The buyer is different, the sales motion is different, and the tolerance for a half-finished product is much lower because the cost of an error is measured in site days.
If you are choosing between them, construction has less competition and harder customers. Property has more competition and easier onboarding.
A practical note on pilots: contractors will test your product on one project before anything wider, and that project will be chosen because it is difficult. Expect the pilot to surface every gap at once. That is uncomfortable and it is also the fastest product feedback you will get anywhere in this list.
Where the openings actually are
Not in another listings portal. The established portals have distribution and a decade of inventory, and that fight is not winnable with a better interface.
The openings are in the operational layer nobody has made pleasant: handover and snagging, facilities maintenance for a building's whole life, service charge transparency, valuation workflow, and the paperwork around leasing that still moves by email. Unfashionable, specific, and paid for.
What these have in common is that they sit after the transaction, where the incumbent portals have no presence and no reason to build. A building is handed over once and then operated for decades, and almost none of those decades are well served by software today. That is a longer market than the sale itself.