BAHRUL ROZAK

Field Agent: Bahrul Rozak

Operation Codename: I-Financing V5

Location: PT IMS, Tangerang

Duration: July 2025 - October 2025

Mission Briefing

This report details my covert operation to implement microservices architecture for the I-Financing V5 Base system at PT IMS. The mission required deep technical expertise in Angular, .Net Core, and microservices patterns while collaborating with a cross-functional team under tight deadlines.

Technical Approach

The existing monolithic architecture was showing signs of strain under increased user load and feature complexity. My team was tasked with designing a scalable solution using the following technologies:

Architecture Diagram

Key Challenges

1. Service Decomposition

Breaking down the monolith required careful analysis of domain boundaries. We identified these core services:

// Example service definition in .NET Core
public class LoanService : ILoanService
{
    private readonly ILoanRepository _loanRepository;
    private readonly IMessageBus _messageBus;
    
    public LoanService(ILoanRepository loanRepository, IMessageBus messageBus)
    {
        _loanRepository = loanRepository;
        _messageBus = messageBus;
    }
    
    public async Task ProcessApplication(LoanApplication app)
    {
        // Business logic here
        await _loanRepository.AddAsync(app);
        await _messageBus.PublishAsync(new LoanApplicationReceived(app.Id));
    }
}

2. Cross-Service Communication

We implemented both synchronous (HTTP) and asynchronous (message-based) communication patterns:

3. Distributed Transaction Management

Implementing the Saga pattern was critical for maintaining data consistency across services:

// Example Saga implementation
public class LoanProcessingSaga :
    MassTransitStateMachine<LoanProcessingSagaState>
{
    public State Submitted { get; private set; }
    public State UnderReview { get; private set; }
    public State Approved { get; private set; }
    
    public Event<LoanApplicationSubmitted> ApplicationSubmitted { get; private set; }
    
    public LoanProcessingSaga()
    {
        InstanceState(x => x.CurrentState);
        
        Initially(
            When(ApplicationSubmitted)
                .Then(context => Log(context))
                .TransitionTo(Submitted)
                .Publish(context => new BeginUnderReview(context.Saga.CorrelationId))
        );
        
        // Additional state transitions...
    }
}

Operational Results

The migration to microservices yielded significant improvements:

Lessons Learned

• Domain analysis is critical: Proper service boundaries prevent costly refactors
• Observability is non-negotiable: Invest in logging, metrics, and tracing from day one
• Team alignment matters: Microservices require cultural shifts in development practices