What this is
A Juejin post-mortem on an interview experience hits a widespread problem: candidates who write "QPS improved 3x" (QPS = queries per second, a standard metric for interface throughput) on their resumes get asked follow-ups like "how did you load test, how did you set concurrency levels," and most can't answer — because that number was stumbled upon, not engineered.
The article's core judgment: interviewers aren't asking for tool names, they're asking for reproducible conditions. A "number from a casual run" can only say "3x improvement" in four characters. A "reproducible number" can say "at the 200 concurrency tier, we went from 430 to 1290." The candidate who survives follow-ups is always the latter.
The article also breaks down a common pitfall: many people have used vegeta (open-source load testing tool) in its open-loop mode (controlling QPS), so when asked about concurrency they can only recall the tool's defaults. The real approach is to climb a concurrency gradient and find the inflection point where P99 (99th percentile response time) starts to climb — that tier is the one worth putting on your resume.
Industry view
The flip side is worth raising — not all interviewers are this "picky." Many teams hire based on whether experience can be applied directly on day one, not on academic reproducibility for any single metric. In other words, this methodology-driven interview style is more of a preference at top-tier firms or performance-sensitive roles. At mid-sized companies or business-driven teams, the bar loosens by a notch.
We also want to flag a risk: the 200 concurrency / 1290 QPS figures in the article are examples. Readers borrowing the thinking is fine, but lifting the numbers directly into an interview will be exposed.
Impact on regular people
For individual careers: Whether you're in tech or not, two questions must be answerable: "what did I do" and "why does it count." People who write only impressive numbers and can't articulate the methodology are being filtered out first.
For enterprise IT: When hiring for technical roles, interview questions can adopt this approach — instead of "what have you used," ask "how did you decide that step, and what's the basis for it." Candidates who pass will be far more reliable.
For the consumer market: This has no direct link to consumers. But it indirectly confirms one thing — however hot the AI gold rush runs, real hiring bars for technical roles haven't dropped; fundamentals matter more, not less.