How this guide works
We do not give you a list of questions to learn by heart. Real interviews do not work like that. An interviewer listens to you first, and then asks about what you said, deeper and deeper, until they find where your knowledge stops. You cannot learn that from a list. You can learn it from watching conversations, and then by practising your own.
So we start where a real application starts: with a job description. We read it together, line by line, and say honestly what it asks for, what it does not say, and who should apply. Then you see how the interviews for this role usually run. Then you follow five different people through the same interview, turn by turn, with notes on what the interviewer is checking, what works, and what goes wrong. At the end, you prepare for your own interview.
The company and the candidates are not real. The job description is a composite: we built it from the patterns that repeat in real Data Engineer postings. The conversations are examples, written from our experience of real interviews on both sides of the table.
Inside the guide
Part 1Read the job description
2 pagesThe job descriptionThe Data Engineer job description that this guide uses, built from the patterns in real postings, and a first read to find the problem behind the long list of tools.
7 minRead it honestlyWhat the Tidewell Data Engineer posting really requires, what is only a wish, what it leaves out (on-call and cost), who should apply, and the questions to ask the team.
13 min
Part 2How the interviews run
1 pageHow the interviews runThe five interviews in Tidewell's process, what each one checks, how a serious interviewer goes from your pipeline to the edge of what you know, and the meter-readings problem that every candidate gets.
12 min
Part 3Five candidates, one role
5 pagesThe same technical interview with five different people. Each conversation starts from what the candidate has built, and goes deeper from there.
The BI developerFatima spent nine years in SQL, reports and data warehouses, and her interview shows how strong modelling and careful testing carry into data engineering, where Kafka becomes her edge, and why she accepts another offer first.
21 minThe software engineerLukas has six years of Java payment services behind him, and his interview shows how strong reliability habits carry into data engineering, and where tables for analysts become his edge.
18 minThe modern stackJordan built a whole data platform in two years with managed tools, and their interview shows what those tools hide, and how honesty at the edge turns a "no" into a good result.
19 minThe veteranVikram has 24 years in data, from Teradata to a cloud lakehouse, and his interview shows how deep experience carries into new tools, including a polite and correct disagreement about Kafka's exactly-once.
21 minThe domain expertNicole spent 7 years in meter operations before she learned SQL and Python. Her interview shows what knowing the meters brings to a data team, and where her engineering stops.
20 min
Part 4Prepare for your own interview
1 pagePrepare for your own interviewTurn what you saw in the five interviews into a plan for your own Data Engineer interview - notes on your pipelines, a small re-run test, SQL and modelling practice out loud, and your questions for the team.
12 min