How RentNinja turns screening work into a structured application.
A practical walkthrough of the data model, workflow, authentication, and AI-assisted intake behind my published RentNinja application.
By Sanjai Syamaprasad · Software Engineer & AI Application Developer · Updated September 29, 2026
The core idea behind RentNinja is to give an operator one place to move from messy applicant information to a structured, reviewable workflow. The interesting engineering problem is not a single score; it is keeping identity, organization boundaries, applicant data, assisted extraction, and follow-through coherent as one system.
1. Start with the organization boundary
RentNinja models an Organization, User, and Applicant. Applicant records carry organization and owner scope so the application has an explicit boundary around which records an operator can access.
2. Make workflow state visible
The application organizes screening work around a dashboard and applicant records. CRUD operations, notes, filters, sorting, affordability calculation, application status, and lease status turn what could be disconnected messages and documents into explicit state that can be reviewed.
Auth.js access
screening dashboard
scoped record
score & labels
review & extraction
notes & status
3. Use AI at the messy edges
The documented AI workflows focus on tasks where unstructured input gets in the way: generating an applicant review, comparing applicant records, and extracting fields from a PDF, image, pasted text, or email summary. The surrounding application remains responsible for storing the result and giving the operator a place to inspect it.
4. Keep the core architecture understandable
The application uses Next.js App Router with TypeScript, MongoDB through Mongoose, Auth.js for authentication, and Tailwind CSS for the interface. Billing routes and environment configuration are kept separate from the core applicant workflow, which makes the system easier to reason about and evolve.
What this structure makes easier
- Extending applicant data without losing organization scoping.
- Giving AI-assisted output a defined place inside a human review workflow.
- Testing protected routes and data behavior independently from billing.
- Explaining the system in product language as well as implementation language.
Where the product goes next
RentNinja is now published at rent.jtekninja.com. Ongoing work is about hardening the operator experience, refining integrations, and improving the handoffs after an applicant is reviewed rather than changing the basic workflow model.
Primary references: the public RentNinja repository and the published application. This article describes the software architecture and does not claim screening outcomes.