Careeroza

Real World Example

Comments in a Production Codebase

In companies, code is read far more often than it is written. A typical Java service at a fintech like Razorpay or PhonePe documents public methods with Javadoc and uses short comments for business rules that are not obvious.

Example

/**
 * Calculates convenience fees for a ticket booking.
 */
public class Main {

    /**
     * Returns the convenience fee for one booking.
     * @param ticketPrice price of the ticket in rupees
     * @return fee in rupees
     */
    static double convenienceFee(double ticketPrice) {
        // Business rule (Finance team, 2024): 2% fee, minimum Rs. 10, maximum Rs. 50
        double fee = ticketPrice * 0.02;
        if (fee < 10) fee = 10;
        if (fee > 50) fee = 50;
        return fee;
    }

    public static void main(String[] args) {
        System.out.println(convenienceFee(200));    // small ticket -> minimum fee
        System.out.println(convenienceFee(1500));   // 2% of 1500
        System.out.println(convenienceFee(9000));   // capped at maximum
    }
}

Output

10.0
30.0
50.0