The dominant factor is never the technology stack — it is uncertainty. Each unanswered question in the brief is converted into a contingency in the estimate. A vendor that has no visibility into the edge cases has to assume the worst. Investing a few days in a proper discovery can cut the overall figure much more than haggling over hourly rates.
Third-party integrations tend to be the second big multiplier. A screen that writes to your own database is easy to estimate; the same feature connected to an old accounting system is not. The unknown hides in the other system: undocumented APIs, long certification processes, fields that mean something different on each side. Ask each bidder to price integrations separately, since that is where the numbers slip.
The requirements nobody writes down silently change the number. A tool used by a handful of staff is a very different build from the same feature set handling thousands of external customers. Security reviews, high availability, web development company scalability, audit logging and accessibility add measurable effort. State them early or you can expect the estimate to move later.
Who actually does the work matters. A day rate reveals very little on its own: one senior developer at a higher rate is often cheaper per delivered feature than a pair of junior hire backend developers who require constant review. Also ask what else appears on the invoice: coordination, quality assurance, infrastructure work and UX design have to be done by someone, software development companies in dubai but they must be itemised.
The number in the proposal is not the total cost. Expect infrastructure, subscriptions and licences, logging and alerting and a change budget annually. A common working assumption says that qatar software development agency in active use needs a recurring percentage of the initial investment per year for updates, security patches and small improvements. Treating the launch as the finish line has always been the most common budgeting mistake.