Interviewer’s Reflections: Evaluating Senior Candidates for Cloud and Big Data Positions

Today I share insights from a friend who works as an interviewer, focusing on what abilities interview questions aim to assess.

Recently I screened many candidates for our team’s hiring quota in Xi’an, a city with many top universities (e.g., Xi’an Jiaotong, Northwestern Polytechnical, etc.). Most candidates came from these schools.

Compared with Beijing, Shanghai, or Hangzhou, Xi’an’s internet ecosystem is weaker. The candidates’ current positions fall into four categories:

Employees or contractors of banking‑technology companies;

Large‑tech firms such as Huawei Xi’an Research Institute or Tencent Cloud, mainly in cloud computing, big data, DevOps, often with management experience;

Outsourced roles for internet companies;

Other lesser‑known companies.

One Huawei department is relocating, forcing many employees to resign, which added several resumes to my pool.

Technical stack: Spark, Hadoop, ClickHouse, K8s, etc. Led big‑data architecture design and technology selection; Provided optimization for data‑flow processing; Promoted new solution implementation; Team management. Key skills: Proficient in C++, Java, Linux; Familiar with Spring, SpringBoot, SpringCloud; Experienced with big‑data tools like Kafka, Flink, Spark; Skilled with Maven, Git; Strong team‑leadership experience. Self‑evaluation: strong coding ability, love for technology, sincere, high pressure tolerance, good team‑management skills.

Although the candidate’s résumé was impressive, the interview did not go smoothly.

Interview dialogue (excerpt):

I: Briefly introduce yourself.

Candidate: Graduated in XX, worked at several companies, now at a research institute doing cloud computing and big‑data work.

I: Describe a project you led, the services involved, technologies used, and how they interact.

Candidate: The project has four services communicating via HttpClient.

I: How are your micro‑services divided, and how do they communicate?

Candidate: (Unclear answer).

I: Find the missing number in a sorted array of length n containing numbers from 0 to n (LeetCode 268 variant).

Candidate: Proposes an O(n²) solution using an extra array.

I: That’s too slow; any better approach?

Candidate: Suggests an O(n) scan without extra space.

I: Any even better method?

Candidate: Could not think of one.

I: I was hoping for a binary‑search solution.

I: What’s the difference between Java’s TreeMap and LinkedHashMap?

Candidate: TreeMap is ordered; can’t recall LinkedHashMap.

I: What Java locks exist?

Candidate: Mainly synchronized.

I: Have you used AQS locks?

Candidate: Something like Reentrant, not sure.

I: Difference between @Resource and @Autowired in Spring?

Candidate: @Autowired injects by type, @Resource by name.

I: When to use each?

Candidate: Mostly uses @Autowired.

I: What’s the difference between a Deployment and a StatefulSet in K8s?

Candidate: StatefulSet is for stateful applications.

I: Why are you leaving your current job?

Candidate: Huawei’s department is being shut down; relocation is not feasible for my family.

Reasons for rejecting the candidate:

The senior role requires leading a team after onboarding;

Team lead must be a technical manager, capable of hands‑on work and industry knowledge;

All team members are subject to code assessments; no one should avoid coding;

We need a colleague with solid fundamentals to guide the team.

My personal insights:

Technical skills can be set aside if certain conditions are met:

If interview answers are vague, it’s better to admit uncertainty;

Senior engineers are expected to excel in both technology and business, often requiring management experience;

Do not switch career tracks unless forced, and only to hot fields like AI or ChatGPT;

Prepare thoroughly before interviewing; avoid fighting unprepared battles.

Additional links:

Why do some programmers always wear headphones at work?

Microsoft’s new chip for Win12: performance breakthroughs?

Legendary 47‑year‑old technologist Chen Hao passes away, leaving a rebellious entrepreneurial legacy.

22‑year‑old flagship phone says goodbye as its Tmall store closes.

Huawei is killing Huawei.