dahirali3823/applicant-service

Purpose and runtime

Credit Risk Assessment System is a Java 17 Spring Boot REST backend that manages applicants, computes configurable credit-risk scores, and returns approve/deny loan decisions. The application starts from src/main/java/com/example/Application.java; HTTP APIs run in the Spring Boot process.

API boundary

Controllers expose JSON endpoints and separate transport concerns from domain services:

• Applicant CRUD: src/main/java/com/example/applicant_service/ApplicantController.java

• Credit-score calculation and explanation: src/main/java/com/example/scoring_service/ScoringController.java

• Loan evaluation: src/main/java/com/example/loan_service/LoanController.java

• Liveness-style status endpoints: src/main/java/com/example/health/HealthController.java

Applicant lifecycle and persistence

Applicant is the central input record for all risk assessment, carrying applicant financial and employment/residency data. ApplicantService owns create/read/update/partial-update/delete behavior and uses the repository boundary for storage:

• src/main/java/com/example/applicant_service/Applicant.java

• src/main/java/com/example/applicant_service/ApplicantService.java

• src/main/java/com/example/applicant_service/ApplicantRepository.java

PostgreSQL is the intended persistence service; connection and application settings are in src/main/resources/application.yml.

Scoring stage

ScoringService receives an applicant identifier, obtains applicant data through the application’s domain layer, and calculates a numeric credit score from applicant attributes and scoring weights. It also produces a human-readable breakdown for the explanation endpoint. CreditScore is the score-domain result/value model.

• src/main/java/com/example/scoring_service/ScoringService.java

• src/main/java/com/example/scoring_service/CreditScore.java

• src/main/java/com/example/scoring_service/ScoringController.java

Loan-decision stage

LoanDecisionService is the downstream policy layer: it evaluates an applicant using score-related and applicant data, then emits a LoanDecision containing the approval/denial outcome. The loan controller is therefore an orchestration-facing API, not a separate persistence subsystem.

• src/main/java/com/example/loan_service/LoanDecisionService.java

• src/main/java/com/example/loan_service/LoanDecision.java

• src/main/java/com/example/loan_service/LoanController.java

Primary control flow

1. Client creates or updates an applicant through /api/applicants; the controller delegates to ApplicantService, which persists through ApplicantRepository.

2. A scoring request identifies an applicant; ScoringService loads its current data and returns either score data or explanatory output.

3. A loan request identifies an applicant; LoanDecisionService applies decision policy based on applicant/scoring results and returns LoanDecision.

4. Health endpoints provide lightweight availability checks independent of the business workflows.

Deployment and infrastructure

Maven builds the Spring Boot artifact using pom.xml. The repository supports containerized execution through Dockerfile and docker-compose.yml; Compose is the likely boundary for the application and PostgreSQL containers. Runtime configuration remains externalized in src/main/resources/application.yml.