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Data Engineer

What does a Data Engineer interview actually cover?

A Data Engineer interview on TheInterviews is the only one of the five where hands-on coding is a substantial part of the assessment rather than a rarity: 7 of its 28 graded interviews ran as coding sessions, a quarter of the family, against 1 of 37 for software engineer. It is the only role in this set that regularly produces the code-quality rubric — code correctness, code quality and efficiency each appear on 7 interviews — alongside the reasoning dimensions. Expect to be asked to write something, usually SQL or a pipeline transformation, and to be graded on how it reads as much as whether it runs.

Drawn from 28 graded Data Engineer interviews by 6 people, between 26 June 2026 and 28 August 2026 — part of the same 177 graded interviews the published rubric draws on. Rubric figures as of 28 August 2026; role breakdown as of 30 August 2026.

Which interview types were actually run

Interview type
Interview typeInterviews
Technical theory only10
Workforce screening7
Technical coding7
Behavioural2
Technical (theoretical)2

Which dimensions the grader actually emitted

Dimension
DimensionInterviews
Technical knowledge17
Conceptual clarity10
Trade-off analysis10
Edge cases10
Communication9
Coding7
Code correctness7
Code quality7
Efficiency7
Problem-solving approach7

Dimensions appearing on fewer than two interviews are omitted. Every per-interview dimension is rolled up onto the five canonical dimensions described on the rubric page.

How these interviews came out

YES
18
of 28 graded interviews
MAYBE
9
of 28 graded interviews
NO
1
of 28 graded interviews

Read the mix as the grader's output, not as a verdict on the people. Our own evaluation, published at /methodology/scorer-compression, found the scorer separates behaviourally distinct candidates far less well than an independent rater does, and the published rubric at /scoring lists that and the other measured limits in full. The transcript is published beside every score; where the two disagree, the transcript is the one that is true.

The only role in this set where code is really assessed

Seven of 28 graded data engineering interviews ran as coding sessions. That is a quarter of the family, and it is the highest share of any of the five by a wide margin — the comparable figure for software engineer is 1 of 37. If you are preparing for one interview on this site by writing code, this is the one.

The rubric follows the format. Code correctness, code quality, efficiency and problem-solving approach each appear on 7 graded interviews here; on most other roles they appear two or three times or not at all. Code quality being graded separately from correctness is the part candidates underestimate: a transformation that produces the right rows but cannot be read by the next person scores below one that does both.

Edge cases mean data edge cases here, and they are graded on 10 of 28

Conceptual clarity, trade-off analysis and edge cases each appear on 10 graded interviews. For this role "edge cases" is rarely an off-by-one — it is the null in the join key, the late-arriving partition, the duplicate that appears only after a retry, the timezone that shifts a daily aggregate by one row.

Naming those unprompted is the single highest-leverage behaviour in this interview, because it demonstrates the dimension the rubric is explicitly looking for and it is the thing that separates someone who has run a pipeline in production from someone who has only written one.

Six people, 28 interviews — the most repeated practice of any role here

This family has the highest interviews-per-person ratio of the five: 28 graded interviews from 6 distinct people. It also has the kindest outcome mix — 18 YES, 9 MAYBE, 1 NO. Those two facts are not independent, and it would be dishonest to present the second without the first.

What this data supports is a claim about practice, not about data engineers: people who sit this interview repeatedly do well on it. What it cannot support is a comparison against the software engineer family, which is almost entirely first attempts. Different populations, not different professions.

Data Engineer interviews — common questions

Does a Data Engineer interview involve writing code?

More often than any other role on TheInterviews. Of 28 graded data engineering interviews between 26 June and 28 August 2026, 7 ran as hands-on coding sessions — a quarter of the family, against 1 of 37 for software engineer. Code correctness, code quality and efficiency were each graded on 7 interviews.

What is graded in a Data Engineer interview?

Across 28 graded interviews the grader most often emitted technical knowledge (17), then conceptual clarity, trade-off analysis and edge cases (10 each) and communication (9). Where the interview involved code, it also emitted code correctness, code quality, efficiency and problem-solving approach — 7 interviews each.

Why is the Data Engineer outcome mix so much better than other roles?

Because it is largely repeated practice by a small group, not a cross-section. The 28 graded interviews come from 6 distinct people, the highest interviews-per-person ratio of the five roles, and the mix was 18 YES, 9 MAYBE, 1 NO. It supports a claim about practice improving outcomes, not a comparison between professions.