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This is a medium difficulty System Design question, commonly asked during Technical Screen rounds at Rippling.

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This question is commonly asked for Software Engineer candidates at Rippling during technical interviews.

Design delivery driver payment system | Rippling Interview Question

Quick Overview

This question evaluates system design and engineering skills related to in-memory payroll services, covering time-interval merging and overlap handling, accurate monetary accounting, API and state-mutation design, and reasoning about correctness under unordered event insertion.

Design a Delivery Driver Salary System

You are designing an in-memory payroll service that calculates and pays delivery drivers based on their worked time. The system must provide accurate cost accruals, support partial payments up to a boundary time, and avoid double-paying overlapping work intervals.

Assumptions (make minimal changes if needed):

Time values are Unix timestamps in seconds; intervals use half-open semantics [start_time, end_time).
Each driver has a constant USD hourly rate after Add_driver (rate changes are out of scope but can be added as an extension).
Record_delivery only records completed deliveries (end_time > start_time). Deliveries can be inserted out of chronological order.
For a given driver, overlapping or adjacent delivery intervals should be merged so the driver is not double-paid for the same minute twice.
Monetary values are tracked in integer cents to avoid floating-point error.

APIs to support:

Add_driver(driver_id, usd_hourly_rate)
Record_delivery(driver_id, start_time, end_time)
Get_Total_Cost()
Pay_Up_To(pay_time)
Total_Cost_Unpaid()

Explain:

Data structures to store drivers, delivery intervals, rates, and payments.
State-mutation logic for each API, including handling overlaps and partial payments.
Object-oriented design that enables accurate and efficient payroll computation, plus complexity trade-offs.

Quick Overview

Design a Delivery Driver Salary System

Assumptions (make minimal changes if needed):

Time values are Unix timestamps in seconds; intervals use half-open semantics [start_time, end_time).

Each driver has a constant USD hourly rate after Add_driver (rate changes are out of scope but can be added as an extension).

Record_delivery only records completed deliveries (end_time > start_time). Deliveries can be inserted out of chronological order.

For a given driver, overlapping or adjacent delivery intervals should be merged so the driver is not double-paid for the same minute twice.

Monetary values are tracked in integer cents to avoid floating-point error.

APIs to support:

Add_driver(driver_id, usd_hourly_rate)

Record_delivery(driver_id, start_time, end_time)

Get_Total_Cost()

Pay_Up_To(pay_time)

Total_Cost_Unpaid()

Explain:

Data structures to store drivers, delivery intervals, rates, and payments.

State-mutation logic for each API, including handling overlaps and partial payments.

Object-oriented design that enables accurate and efficient payroll computation, plus complexity trade-offs.

Design delivery driver payment system

Quick Overview

Design a Delivery Driver Salary System

Solution

Comments (0)

Design delivery driver payment system

Quick Overview

Design a Delivery Driver Salary System

Solution

Comments (0)