Implement N+1 query prevention add batching and eager-loading where missing

[nanaf6203-bit]

Problem

Several N+1 query patterns exist: SessionsService filters sessions in-memory, DashboardService loads recommendations with loops, NotificationsService loads preferences separately.

Expected Outcome

Zero N+1 query patterns in the codebase.

Acceptance Criteria

• Audit all services for N+1 patterns
• Fix each pattern: use include, batch requests, or cache results
• Add automated detection via Prisma event logging

Files Affected

src/sessions/sessions.service.ts, src/dashboard/dashboard.service.ts, src/notifications/notifications.service.ts

Difficulty

Medium

Estimated Effort

Medium (1 week)

Labels

performance, database, refactoring

[khalyaro]

@khalyaro has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi
Can i please work on this issue?

ℹ️ Repo Maintainers: To accept this application, review their application or assign @khalyaro to this issue.

[ajulaybeeb]

@ajulaybeeb has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi Maintainer, haven reviewed the description of the issue, and well experienced with Js Library,
I would like to hop on the issue and sure to deliver at ETA 2hrs

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[TS-mfon]

@TS-mfon has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

GM

I'm a Blockchain developer

Please can I work on this issue

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[Caneryy]

@Caneryy has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello! Can I work on this issue please?

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Caneryy to this issue.

[drips-wave]

Congratulations, @khalyaro! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @khalyaro: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

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