The purpose of this exercise is to complete a small data pipeline that aggregates and transforms input data according to requirements driven by the data science team. The actual format of the output will be shared during the exercise. You will pair with one of our Senior Engineers to do this. Please ask as many questions as you feel you need before starting the coding exercise.

Before the interview

You can find the task for this part of the interview process attached to the email this guide was sent with. 

Read through the documents and the data provided, noting down any questions you have ahead of the interview.

  • Prepare and set up a local Python environment and IDE. We suggest PyCharm, but use whatever you are comfortable with

  • Ensure that it can run some sample code through pytest / unittest

  • Lastly choose Apache Spark or Pandas as your solution framework

During the interview

  • Ask any questions you feel are necessary to complete the task
  • Test your code

  • Explain your logic / approach to the exercise as you are coding

  • Ask for help / guidance if you get stuck

If you have any questions, or the above isn't clear please let me know.

As always, you’ll have 5-10 minutes at the end of the session to ask any questions you might have.



In this interview you will pair with a Senior Engineer to discuss a hypothetical Architecture and Systems Design problem that you would build to deploy onto. The exercise is interactive. You will be working alongside the interviewer to come up with a working solution. Ask as many questions as you feel are necessary to be successful in the interview.

Before the interview

Before the session, please familiarise yourself with an online drawing tool. We use Miro internally, but you can also use (which is free and requires no registration).

Please also read our detailed Systems Design guide here: Systems Design Guide.

During the interview

  • You will be given a high-level problem statement

  • The problem is deliberately vague. You are encouraged to ask questions and clarify specifications

  • You will work with your interviewer to develop a working solution

  • You will sketch down your design using your drawing tool of choice

What we expect by the end of the session

  • Block diagram / workflow describing your solution

  • Explanation of trade-offs / choices in arriving at your solution

  • A working solution for a simple base case - this is more important than solving for all the complex scenarios

Please think about all factors you would take into consideration when designing a system. These incluce security, scalability, reliability, maintainability, monitoring / alerting, data lineage and data validation.

As always, you’ll have 5-10 minutes at the end to ask your interviewer any questions about the role and Tractable.



This is the final stage in our recruitment process. The interview is generally conversational with questions to determine your fit with Tractable and our values. It is also designed to help you decide whether Tractable is the right fit for you.

We’ll assess you against several of our company values. Ensure you check our careers page to read up on these, and have some examples to hand to discuss with us: Tractable Careers.

During the session we will be assessing

1. Communication and collaboration: 

  • We’re looking for collaborative people who will communicate well with the rest of the team as well as other stakeholders 

  • You should be able to give and receive constructive feedback

  • Can you have difficult conversations? We don’t do everything right and need our people to tell us when we go wrong

2. Results obsession:

  • We are looking for people who are focused on results (over inputs) and understand the impact of their work. Not just on a technical level, but from a product benefit and customer impact perspective as well

  • We will ask about examples of challenging situations that show how you reacted to them, how you prioritised efforts and how you got through them

  • Sometimes the right result isn’t the one we want. So we'd also like to explore any relevant scenarios, what you learnt from them and what you would do differently next time

3. General fit:

  • Discuss your career motivations 

    • Why did you transition roles? 

    • What are you looking for?

    • What are your longer term aspirations? 

    • Why Tractable? 

We’ll also give you 5-10 mins at the end of the interview to ask any questions you might have about the role / Tractable.

As always, please let us know if you need any adjustments to be made for your interview process.