Start with the business problem, not your preferred technology. Who will use it day to day, how often, and what happens today? A vendor who knows what you are trying to achieve can propose a cheaper route to it; someone handed only a feature list can only price your assumptions along with the work.

Describe the scope as short scenarios: time and materials contract what the user does and what the system does in response. Equally important, write down what is out of scope. A written out-of-scope list prevents more argument later than the rest of the brief combined. Mark too which parts are firm and ruby on rails vs laravel which are still open — the difference changes the price, and pretending everything is fixed only hurts you.

Set out your constraints. These include systems you must integrate with, the data you already hold and its condition, compliance requirements, user volumes, saas custom development supported browsers or devices and any technology you are committed to. If there is a hard date, say why: an experienced team is usually able to resequence the work to meet it, but only if they know it exists.

Write down what done means feature by feature. Acceptance criteria do not require special syntax: igaming software development a short paragraph setting out what a user should be able to do is sufficient. This one section reduces acceptance testing considerably and closes off the usual argument at handover.

To close, say what you expect back. Require an itemised estimate, a written list of assumptions, the main risks and a range rather than a single figure. Read a wide range as a signal about the brief: it normally identifies exactly which requirement is unclear. From there tighten that section and ask again — the revised figure tends to be much more reliable.