A number produced without questions counts as a bad sign. An experienced provider responds with questions first: about users and volumes. A vendor that commits to a figure with no clarification is working from a template, and that guess will be corrected later — and you will pay for it.
Look out for any distance between the people you meet and those who eventually appear in the repository. Ask for the names and CVs of the actual team in the contract, with wording covering replacement. A vendor swift development agency that only offers a pool of resources and refuses to name people is reserving the right to assign anyone it likes.
Insist on the source repository from the start. A team that shows a build only at the end of each phase is asking you to trust a black box. Daily commits reveal who is really on the project far better than a weekly report. The same applies to the build and php software development company deployment setup: if it does not exist, quality claims remain unverifiable.
Ambiguous phrasing around code ownership is never an oversight. The agreement should state explicitly that all deliverables become the property of the client as they are paid for. Check also which country’s law applies and the milestone terms: a request for most of the money up front with no deliverable attached takes away your only leverage.
Lastly, look at how they communicate. Confirm how many hours you will share each day, which contract model for software development person is expected to answer questions and within what time. Some genuine overlap is usually enough; none at all turns a five-minute question into a twenty-four hour round trip. Sloppy written English in the early emails will not improve once the work starts.