Career6 min read10 sections

How to crack a data engineer interview at Google

A calm, step-by-step plan for a Google data engineering interview, written for students. What the stages are, what to practise, and how to use 8 weeks.

Updated Written for: Students and freshers aiming for a data engineering role at Google.

What you will learn

  • Expect coding and SQL screens, then a loop of interviews, so practise both while talking out loud.
  • Know what BigQuery, Dataflow and Pub/Sub are for, in one sentence each.
  • Student internship programmes are a common first step, so check the careers page for your year.
  • Follow an 8-week plan: SQL, windows, Python, pipelines, one project, then mock interviews.
On this page
  1. What the role looks like
  2. How the hiring process usually runs
  3. What they test and how to practise it
  4. Tools and ideas worth knowing by name
  5. Questions to practise
  6. How to show clear thinking
  7. An 8-week plan
  8. Mistakes freshers make
  9. How to talk about your project
  10. Where to start today

Most guides about getting into a big company are written for software engineers. This one is for a data engineering role: the person who moves data from where it is created to where people can use it. It explains what Google interviews usually look like, what to practise, and how to spend 8 weeks. You do not need to know any of this already.

1Apply with a clear resume

One page, with one or two projects you can explain.

2Recruiter call

A short chat about you, the role and the timeline.

3Technical screens

Coding and SQL, solved while you talk.

4Interview loop

Several interviews in one day or a few days.

5Review and decision

Feedback is reviewed together before an offer.

Figure 1. A typical path: apply, recruiter call, technical screens, a loop of interviews, then a review of all the feedback.

What the role looks like

At Google, data engineers build and run the pipelines and tables that other teams rely on for reports, products and experiments. Job titles and team names differ, so read each posting for its own list of skills instead of assuming one standard job.

Google also runs internship programmes for students, and these are a common first step for freshers. Check the careers page for the programmes open to your year and country.

How the hiring process usually runs

Read this as a typical order, not a promise. Some stages are skipped for some roles, and for students the first stage is often an internship application.

  1. Application and resume screen. A person or a tool checks that your skills match the posting. Keep the resume to one page and name the tools you used (SQL, Python, a database).
  2. Recruiter call. A short call about your background and interests. Have a 30-second answer for "tell me about yourself" ready.
  3. Technical phone or video screens. You write code or SQL while talking. Expect easy to medium problems. Speak your reasoning out loud.
  4. The interview loop. Several interviews, often a mix of coding, SQL or data questions, design thinking for data, and questions about how you work with others.
  5. Review. Interviewers write feedback and a group reviews it. You may be asked to talk to teams about where you would fit.

What they test and how to practise it

Each row is one thing an interviewer wants to see, what to practise for it, and where to practise it here.

What they checkWhat to practisePractise it
Coding fundamentalsHash maps, sorting, two pointers, simple recursionPython practice
SQLJoins, GROUP BY, window functions, finding duplicatesSQL practice
Data thinkingWhat one row means, how to check a resultLearn: SQL track
PipelinesRaw, clean and reporting layers, reruns that are safeWhat is a data pipeline?
Working with peopleA short story about a problem you solved in a teamWrite 3 stories and practise them aloud

Tools and ideas worth knowing by name

Google describes several of its data products publicly. Knowing what they are for helps you follow the conversation.

  • BigQuery is a data warehouse you query with SQL. Practise standard SQL and the idea of reading only the columns you need.
  • Dataflow runs data processing jobs on the Apache Beam model, for both batch and streaming data.
  • Pub/Sub is a message service that carries events from one system to another, like Kafka.

You do not need to be an expert in any of these. You need to say what each one is for, in one sentence, and show that you can learn it.

Questions to practise

These are the shapes of question to practise, written the way an interviewer might say them. They are not a leaked list. Solve each one yourself first, then check your answer.

  • Given an orders table, return the top 3 products by revenue in each category.
  • Find the customers who placed an order every month this year.
  • A table has duplicate rows for the same event. Keep only the latest one.
  • Count how many times each word appears in a list, and return the most common three.
  • Merge two sorted lists into one sorted list.
  • Your daily table is missing yesterday's data. How do you find out, and how do you fix it safely?

How to show clear thinking

Google-style interviews often reward the way you break a problem down. Restate the problem, give a small example, say the simple way first, then improve it. Say the time cost of your solution in plain words, such as "this loops through the list once, so it grows in step with the list".

An 8-week plan

Study about an hour a day. If you have less time, stretch each row and keep the order.

WeeksFocusWhat you can do at the end
1 to 2SQL basics: joins, GROUP BY, NULLAnswer easy SQL questions without looking anything up
3 to 4Window functions, CTEs, deduplicationSolve "top N per group" and "latest row per key" questions
5Python: dictionaries, loops, strings, filesSolve easy coding questions in about 20 minutes
6Pipelines and warehouse ideasExplain raw, clean and reporting layers and how a rerun stays safe
7One project, written upWalk through the project in 5 minutes and answer "what went wrong?"
8Mock interviews for GoogleTalk through a problem out loud while you solve it

Mistakes freshers make

  • Memorising answers. Interviewers change the data and the wording. Learn why a solution works, not what it looks like.
  • Going silent. Say what you are thinking. A wrong answer with clear thinking often scores better than a right answer nobody understood.
  • Skipping the checks. After you write a query, say how you would check it: count the rows, look for NULLs, look for duplicates.
  • Having no project. One finished project you can explain beats five half-finished ones.
  • Not asking questions. If a question is unclear, ask about the data and what one row means. That is what a working data engineer does.

How to talk about your project

Pick one project and prepare a 5-minute story: the problem, the data, the design, one thing that went wrong, and what you would change. Interviewers at any company, including Google, tend to spend the most time on "what went wrong", because it shows how you think. Build one from the projects page and write it up with a README.

Where to start today

Open the SQL practice problems, solve three, and write down what confused you. Then pick the Learn track that covers it. A small start today is worth more than a perfect plan next month.

Keep practising

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