Software Engineer · Online Assessment · System Design

Anthropic — Software Engineer

Level: Senior-Level

Round: Online Assessment · Type: System Design · Difficulty: 6/10 · Duration: 60 min · Interviewer: Unfriendly

Topics: System Design, Data Structures, Hashmaps, Time Management

Location: Mountain View, CA

Interview date: 2026-01-31

Summary

Design a worker management system as part of the online assessment.

Details

The task was to design a worker management system with the following functionalities:

1. boolean addWorker(String workerId, String position, int compensation)

   • Adds a new employee to the system along with their position and salary.
   • If the workerId already exists, do nothing and return false.
   • If the employee is successfully added, return true.
   • Both workerId and position consist of only English letters and spaces.

2. String registerWorker(String workerId, int timestamp)

   • Records the time an employee enters or exits the office.
   • Calls to this function will be in strictly increasing order of timestamp.
   • If workerId is not in the system, return "invalid_request".
   • If the employee is currently out of the office, this marks their entry.
   • If the employee is currently in the office, this marks their exit.
   • Return "registered" if the entry or exit is recorded successfully.

3. int get(String workerId)

   • Returns the total time the employee has spent in the office.
   • Only fully completed office sessions (entry followed by exit) count. If an employee is currently in the office, that ongoing session is not included.
   • Return -1 if workerId is not found in the system.

Example Usage:

`java OfficeManager officeManager = new OfficeManager();

officeManager.addWorker("Ashley", "Middle Developer", 150); // true officeManager.addWorker("Ashley", "Junior Developer", 100); // false officeManager.registerWorker("Ashley", 10); // "registered" officeManager.registerWorker("Ashley", 25); // "registered" officeManager.get("Ashley"); // 15 (25 - 10) officeManager.registerWorker("Ashley", 40); // "registered" officeManager.registerWorker("Ashley", 67); // "registered" officeManager.registerWorker("Ashley", 100); // "registered" officeManager.get("Ashley"); // 42 ((25-10) + (67-40)) officeManager.get("Walter"); // -1 officeManager.registerWorker("Walter", 120); // "invalid_request" `

My Approach:

I would use HashMaps to store worker information and their entry/exit times. I would need to handle edge cases like invalid worker IDs and incomplete work sessions. The timestamps are strictly increasing, which simplifies time calculations.

`python from typing import Dict

class Employee: def init(self, role: str, salary: int): self.role = role self.salary = salary self.lastEntryTime = None # None means currently not in office self.totalTimeInOffice = 0 self.present = False # Track if employee is currently in office

class WorkerSystem: def init(self): self.employees: Dict[str, Employee] = {}

def addWorker(self, workerId: str, role: str, salary: int) -> bool:
    if workerId in self.employees:
        return False
    self.employees[workerId] = Employee(role, salary)
    return True

def registerWorker(self, workerId: str, timestamp: int) -> str:
    emp = self.employees.get(workerId)
    if emp is None:
        return "invalid_request"

    if not emp.present:  # Employee is entering
        emp.lastEntryTime = timestamp
        emp.present = True
    else:  # Employee is leaving
        emp.totalTimeInOffice += timestamp - emp.lastEntryTime
        emp.present = False
        emp.lastEntryTime = None  # Reset entry time
    return "registered"

def get(self, workerId: str) -> int:
    emp = self.employees.get(workerId)
    if emp is None:
        return -1
    return emp.totalTimeInOffice

`

Key Considerations:

• Efficient data structure selection (HashMap for quick lookups)
• Proper handling of timestamps and session calculations
• Error handling for invalid inputs