Data flow from AEP Web SDK to Real Time CDP profile

I'm not sure what you mean by "I randomly see many eVar values missing under profile of a user [email address as identity] in RTCDP". Why would you expect to see eVar values in the Real-time Customer Profile? Does your schema include one of the "Adobe Analytics ExperienceEvent" field groups or so you have xdm fields named "eVar#" being sent to Platform?

Also, how are you looking for them? Are you opening the profile in Platform UI > Profiles > [Opened Profile] > Events? As @jayakrishnaaparthasarathy , this data would not be attribute data in Profile, it would be attached to a specific event.

How are you passing the identity? In identityMap or as an identity-labeled field in your schema? I would expect you would be able to see all of the identities (ECID and email address) when you open the profile in the Detail view.

Hi @neelabh_  - Hope, this clarify your question. Please let us know incase if you required anything else.

Thanks everyone for the response.

I had a discussion with Adobe team where we debugged the complete flow and identified a couple of issues and then proceeded with a reimplementation. The application is working fine now as expected after reimplementation. I would like to share the points identified so that it may help others facing similar issues in future.

01. The first point we identified was that though we could see the data captured in AEP debugger but it was never stored in AEP.  It was confirmed when we checked 'streaming end to end' window for Monitoring in Data Management section and found that certain records appeared failed with reason 'null value present for some eVars'. This led us to conclude that the issue is with launch implementation which is leading to null value exception for eVar values. We tried to set default values for many such eVars in launch, that were identified as error in data monitoring but unfortunately it did not work.
So the recommendation was to go ahead with a reimplementation by avoiding use of Analytics variables [evar & props] as Adobe Analytics was NOT in our scope of application but was used only to pass data to AEP. As a best practice we were advised not to use Adobe Analytics Experience Event Template field group in XDM ExperienceEvent to capture values from website for AEP [and subsequently Analytics variables via data elements in Launch], if Adobe Analytics is not involved.
We were suggested to create custom field groups under XDM ExperienceEvent and use the same to capture values in launch through via data elements. Although this may not fix the issue, but it eased out the process by removing ambiguity and gave us clarity in terms of Launch rules and schema variables because it helped to add context to data through custom names rather than just naming them as evars. Once this was done, we could see all the data now being recieved in AEP without any error in the records [checked in Data Monitoring & Dataset] (reimplementation fixed the issue as we removed previous launch rules of populating evars)

02. The second part of the issue was fragmented data in CJA where we could not frame a full journey with dimensions working independently but not in relation with event and profile schema taken together. The root cause of this issue was incorrect connection created for CJA where we had selected primary identifiers for profile and event schema. We had two profile schemas and 1 event schema. For Profile schema A & B Email ID served as primary identifier, while for event schema ECID was primary identifier with email id as other identifier field. When we created connection in CJA we choose Email ID as 'Person ID' (for profile schema A & B ) while selecting ECID as 'Person ID' for event schema. This was incorrect and so we created a new connection where email ID served as 'Person ID' from both profile schemas and event schema to fix this issue.