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Hiring
Intermediate

Sr. Java Developer: fix a bug and call your manager

Time available:45 minutes
|
Available in
+8
ByAnthropos
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Your mission in this simulation
1
The challenge

A critical disruption has hit the shipment-tracking service, risking client deliveries and the company’s reputation.

2
The issue

A key Java class is causing instability due to null handling and thread safety issues, threatening strict SLAs.

★
Your goal

Your goal is to debug and fix the code, then clearly explain your solution and its business impact to your Engineering Manager.

Your Role
Senior Java Developer@ TransWay Logistics

You are a Senior Java Developer at TransWay Logistics, a leader in real-time shipment tracking.

Other participants
Michael KleinEngineering Manager
Context

TransWay Logistics is a top American logistics company, recognized for its real-time shipment tracking and delivery solutions. Serving over 1,200 clients—including many Fortune 500 companies—the company manages more than half a million shipments daily using a robust backend built on Java, PostgreSQL, and MongoDB, all hosted on AWS. Their infrastructure is engineered for high reliability and rapid scaling, ensuring seamless operations even during major traffic surges. TransWay’s reputation is built on operational excellence, proactive incident response, and a commitment to meeting strict service-level agreements (SLAs), with significant financial stakes tied to system uptime and performance.

You step into the role of Senior Java Developer at TransWay Logistics, tasked with resolving critical disruptions in the company’s shipment-tracking service. Your mission unfolds in two phases: First, you will review and debug a key Java class in the tracking system, identifying and correcting issues related to null handling and thread safety—all within a single code editor and without running the code. Next, you will engage in a one-on-one voice call with the Engineering Manager, presenting your root cause analysis, explaining your technical fixes, and discussing the business impact and preventive strategies. Your approach must be methodical, evidence-driven, and aligned with both technical and business priorities.

  • Analyze and edit the Java code to resolve stability and concurrency issues.
  • Clearly communicate your findings, technical changes, and business implications to the Engineering Manager in a voice call.
  • Demonstrate strong skills in technical communication, Java, and code debugging to ensure the solution meets business-critical requirements.
Evaluated Skills
Technical Documentation and CommunicationJavaCode Debugging
Helpful for
Senior Java DeveloperBackend EngineerSoftware Engineering Team Lead