Service base for NGO

We are an NGO currently undertaking a personal project requiring an App and Web expert. Specifically, we need a Senior-level App Developer with proficiency in Java and Javascript. The project, titled “Service base for NGO”, primarily involves backend work. Given the nature of the project, we are open to long-term engagement as may be necessary. Although it’s a single job offer, we might consider a paid hire depending on the task’s complexity. The expert can work remotely as there will be no need to perform tasks on-site. At this point, we have not set a budget and are ready to receive offers from qualified freelancers fitting our requirements.

In what capacity are you hiring?
As an individual for a personal project

Where are you in the hiring process?
I will possibly make a paid hire

Is this an independent one off job, or part of a larger project?
Single job with no follow up work

For what period of time will the freelancer be needed?
Long term

What freelancer experience level is needed? (per hour)
Senior: $75-100