An estimate that arrives instantly counts as a bad sign. An experienced provider responds with questions first: about who owns the data and what happens on failure. A provider that quotes with no clarification is probably pricing a guess, and that guess resurfaces as a change order — on your budget.

Look out for a gap between the engineers on the sales call and the people who will code. Ask for custom retail ecommerce software development specific people rather than roles in the statement of work, with wording that requires notice before anyone is swapped. A provider that only offers abstract roles and refuses to name people is keeping the right to assign anyone it likes.

Require access to the repository from the first week. A team that delivers code only at milestones is inviting you to take delivery on faith. Regular commits and pull requests show you the actual pace far better than a weekly report. The same applies to the build and deployment setup: if nothing runs automatically, assurances about quality remain nothing more than words.

Vague phrasing around IP is never an accident. The agreement should state plainly that all outputs produced under it become the property of your software development company as they are paid for. Check also the jurisdiction and the payment schedule: a large upfront payment with nothing due in return for weeks eliminates any leverage you would otherwise keep.

Last, examine how they communicate. Confirm what overlap you will share with your working day, who handles questions and within what time. A few hours of overlap generally works; zero overlap converts every clarification into a day of delay. Sloppy written English in the proposal rarely improves later.