Begin with relevant experience, not the number of logos on the website. Ask for two or three engagements that sit close to your technology consulting company stack, and then ask whether those engineers are still with the kotlin software development company. A serious vendor is happy to connect you with the people who would work on your project. Vague answers at this stage usually mean the demo work came from somewhere else.
The paperwork needs more attention than the sales deck. A few clauses carry most of the weight: ownership of the code, non-disclosure, and termination and handover. Every artifact should transfer to you once invoices are settled, along with source code, designs and infrastructure as code. Watch for any clause that leaves reusable components outside the transfer, since this is frequently the dependency that makes switching painful.
Find out how the estimate was built. A serious estimate arrives with the assumptions behind it, a breakdown by feature or module and an explicit range. A fixed price only makes sense when the specification is complete; otherwise the supplier adds a risk premium and you fund the buffer regardless. Time and materials puts the risk on your side, so it requires a sprint cadence, demos and a budget cap.
Process beats the number of developers. Find out how a new requirement enters the plan, who writes the acceptance criteria and what is livewire in laravel how quality assurance works. A well-run team should be able to walk you through a live build at the end of each sprint. Clear, written acceptance criteria are the only reliable protection against an argument at delivery time.
Before signing, consider the day you no longer need this vendor at the start rather than at the end. Insist that the repository sits on infrastructure you own from the first commit, and that a readme and architecture notes are kept current as the code changes. A vendor with nothing to hide says yes immediately; resistance at this point tells you most of what you need to know.