FHIR Expert

We are a team of Stanford physicians and engineers who have built an Epic-integrated SMART on FHIR web application. We have extensive long-term work opportunities, but we will start with a short-term tangible fixed project, so that we can get to know each other better. Three deliverables:
1) Push clinical impression (ICD10 diagnosis) for a clinical encounter from our app to Epic (STU3)
2) Push new clinical note into patient's chart from our app.
3) Pull all signed orders from current encounter (patients in emergency department and urgent care).

Proof of function in our Epic Sandbox (simulator) and with our customer hospital.

For these deliverables, which FHIR APIs make sense? What considerations should we be thinking about? Are there opportunities we haven't considered? What architecture would it take to make it happen? What potential problems could arise? Troubleshooting our team's implementation (we have a strong relationship with Epic and with our client's IT department, and we have excellent engineers, but we don't have deep integrations/FHIR experience).

We have an incredible product and exciting team - we look forward to talking with you!