Hello , I would suggest to be more specific as Application Development in IoT is highly specific for every industry and even use cases in the same industry. So the basic questions you need to ask first - who will be using the Application? what are the devices you are making IoT ? What is the data volume per day per session per month ? What is the uplink/downlink speed per device? How many devices should be rolled out? Is that data being collected in the Cloud or elsewhere? How secure the Application/Data should be ? What are the geographies - Global, USA, EMEA, APAC etc? Based on the profile you can find the right Architecture and then you can get a reasonable Application development supplier. I can discuss on the phone in more detail.