Interview Experience and Technical Q&A for a Java Backend Position at Tencent Cloud (Xi'an)

The author, a dedicated programmer, explains recent personal changes—including a move to Xi'an due to a new job opportunity—and reflects on the local tech job market, noting both the presence of major companies and the challenges faced by candidates.

Choosing to interview for a Java backend role at Tencent Cloud in Xi'an, the author outlines the interview process and presents the questions asked by the interviewers.

Interview Question 1: Self‑introduction and project experience

The candidate is advised to tailor the answer to personal project history.

Interview Question 2: Redis master‑slave synchronization mechanism

The answer covers full resynchronization and partial resynchronization, with a link to a detailed explanation.

Interview Question 3: Redis memory usage and expiration data handling

The response describes resource planning based on business QPS, deployment strategies, and expiration data eviction policies, with a reference link.

Interview Question 4: Real‑time recommendation system using Streaming

The solution involves a custom wrapper around Kafka Consumer to abstract version differences and support multiple data sources.

Interview Question 5: Why is Kafka so fast?

The answer mentions Kafka’s zero‑copy mechanism and provides a link for further details.

Interview Question 6: Handling duplicate consumption in Kafka

The author notes that duplicate consumption was tolerable for the project and points to a resource describing mitigation strategies.

Interview Question 7: Implement a blocking queue

The candidate is encouraged to research solutions online, with a focus on improving concurrency.

Interview Question 8: MySQL familiarity and transaction types

A brief overview of ACID properties and isolation levels (read uncommitted, read committed, repeatable read, serializable) is given.

Interview Question 9: MySQL MVCC mechanism

The answer touches on InnoDB’s use of undo logs and version numbers.

Interview Question 10: JVM garbage collection phases

The four phases—initial mark, concurrent mark, remark, and concurrent sweep—are explained as ways to achieve low latency on multi‑core CPUs.

In summary, the interview covered a range of backend topics, most of which the author had previously studied, and the article aims to help others preparing for similar interviews while emphasizing the importance of solid fundamentals.