Startups often outsource the development of apps, prototypes, algorithms, etc.

However, just because the deliverables have been received does not automatically mean that the patents for that technology are assigned to them.

In fact, during the process of preparing a patent application based on outsourced development results, disputes with the outsourcing company occur frequently.
If there is no clause in the contract regarding 'intellectual property rights assignment', the organization of inventors (creators) and applicants can become tangled. It is not uncommon to see excessive legal costs incurred while exchanging written notices.

If you are conducting development work through external contracting, consider adding a clause regarding IP assignment in the contract (the text below is an example).

“The intellectual property rights (including application and registered rights) for the deliverables developed under this contract shall belong to the client, and the developer is obliged to cooperate in the patent application and registration process.”

This one line prevents post-disputes, the risk of government grant recovery, and conflicts over joint applications.