A quote that comes back within a day is a warning, not a service level. A competent team returns clarifying questions before any number: about integrations. A provider that prices before understanding the scope is simply pricing a guess, and a guess becomes a change request later — at your expense.
Look out for any distance between the engineers on the sales call and those who eventually appear in the repository. Insist on specific people rather than roles in the contract, crypto igaming platform development with a provision about substitutions. A provider that talks only about a pool of resources and never names individuals is reserving its own flexibility at your cost.
Require the source repository from the start. A team that shows a build only at the end of each phase expects you to trust a black box. Daily commits reveal how many people are really working far better than a slide deck. The same applies to the build and deployment setup: if nothing runs automatically, software development agency quality claims are nothing more than words.
Ambiguous wording in the contract around IP is rarely an accident. The document must state explicitly that all outputs produced under it transfer to your kotlin software development company as they are paid for. Look too at the jurisdiction and how payments are structured: heavy prepayment with no deliverable attached eliminates any leverage you would otherwise keep.
Finally, pay attention to how they communicate. Confirm how much working-time overlap you will share with your timezone, which person answers day-to-day questions and within what time. Four hours of overlap is usually enough; none at all turns a five-minute question into a day of delay. Unclear written communication in the proposal will not improve under delivery pressure.