Next.js+MongoDB Developer for Car Listings Fix

We’re looking for an experienced Next.js + MongoDB developer to fix and optimize our template system for a car listing platform.
The platform supports country-specific car templates (e.g., Japan, China, China-Hybrid, Cayman, etc.), but the current system faces critical issues related to data isolation, template handling, and frontend synchronization.

Key Issues to Address
Critical Problems

Template Data Isolation:
Deleting or editing features/details in one template currently affects all other templates.

Default Template Logic:
The “Default” template should function as a virtual/synthetic base, not as a database document, but is currently handled inconsistently.

Template Switching:
Switching between templates doesn’t properly filter or reload associated features and details.

Data Consistency:
Some templates (e.g., china-hybrid) result in 404 errors or redirect incorrectly to the default template.

Reference System Integration:
The new referencedFeatures and referencedDetails system is only partially implemented.

Secondary Issues

Legacy Fields:
Old fields like visibleFeatures and visibleDetails are still in use alongside the new reference system.

API Inconsistencies:
Certain endpoints return inconsistent or mismatched data structures.

Frontend State Management:
Template switching doesn’t consistently update the UI or component state.

Error Handling:
Error messages lack clarity and fail to surface useful debugging information.

Tech Stack

Frontend: Next.js 14, React, TypeScript, Tailwind CSS

Backend: Next.js API Routes, MongoDB (Mongoose)

State Management: Jotai Atoms, React Hooks

UI Components: Custom components using Lucide Icons


Ideal Candidate

Strong experience with Next.js (v13+), React, and MongoDB/Mongoose.

Proven experience designing modular data systems with template/reference logic.

Ability to identify and fix data isolation and state synchronization issues.

Attention to detail in both backend logic and frontend behavior.

Deliverables

Fully isolated and consistent MongoDB template system.

Standardized APIs and cleaned-up database schema.

Stable, bug-free template switching on frontend.

Documentation for all fixes and structural changes.