Wire Frame 🌪 (Fintech)

Balsamiq is the best wireframe tool out there. Easy to use and you can easily express your ideas without going through a steep learning curve

Everything depends on what kind of a prototype they need. For the most basic one, you don't need to hire anyone, you'll be okay using a free tool like https://www.mockflow.com or https://www.mockflow.com. Unlike Sketch or Figma they don't require any design knowledge and the apps are super easy to use. The drawback is - you're pretty limited in what you can achieve.

If you need higher fidelity mockups that resemble a finished product you'd be better off hiring a designer with experience in UX and UI. They could use Sketch or Figma (or Adobe XD) to create exactly what you want (without limitations of basic mockup software/apps). These mockups can be then uploaded to Invision when it's easy to create a clickable prototype that can be shared with stakeholders via e-mail.

It really depends on what do you want your end goal to be. If you'd like to quickly present a flow or an idea - the first option is much more efficient. However if you need something more complex and high fidelity you might be better off hiring a designer.

A wireframe doesn't need a dev or any particular technical knowledge.

Depending on the required fidelity, you can use something simple like Balsamiq Wireframes or create a full fledged click dummy with Adobe XD, Sketch or figma

3. Start by creating it yourself using any one of the many popular prototyping tools for creating app mockups (e.g. Balamiq, Figma, InVision, etc.)

Wireframes are meant to be rewired, but they are critical for sharing and conveying ideas early in a project.