Werfen, founded in 1966, is a global leader in developing, manufacturing, and distributing specialized diagnostic instruments and related solutions, primarily used in hospitals and clinical laboratories. With core business lines in Hemostasis, Acute Care, and Autoimmunity diagnostics, Werfen is committed to innovation, quality, and improving patient care.

As a Data Engineer at Werfen, you will engage in hands-on experience that combines technical and business acumen. The role involves process optimization, data management, and providing support for continuous improvement efforts. Ideal candidates possess strong analytical skills, creativity, and leadership potential.

If you’re looking to join a dynamic and challenging environment, this Interview Query guide is for you. We'll walk you through Werfen's Data Engineer interview process, share commonly asked questions, and provide invaluable tips to help you succeed. Let's get started!

Submitting Your Application

The first step is to submit a compelling application that reflects your technical skills and interest in joining Werfen as a Data Engineer. Whether you were contacted by a Werfen recruiter, or have taken the initiative yourself, carefully review the job description and tailor your CV according to the prerequisites.

Tailoring your CV may include identifying specific keywords that the hiring manager might use to filter resumes and crafting a targeted cover letter. Furthermore, don’t forget to highlight relevant skills and mention your work experiences.

Recruiter/Hiring Manager Call Screening

If your CV happens to be among the shortlisted few, a recruiter from the Werfen Talent Acquisition Team will make contact and verify key details like your experiences and skill level. Behavioral questions may also be a part of the screening process.

In some cases, the Werfen Data Engineer hiring manager stays present during the screening round to answer your queries about the role and the company itself. They may also engage in surface-level technical and behavioral discussions.

The whole recruiter call should take about 30 minutes.

Technical Virtual Interview

Successfully navigating the recruiter round will present you with an invitation for the technical screening round. Technical screening for the Werfen Data Engineer role is usually conducted through virtual means, including video conference and screen sharing. Questions in this 1-hour long interview stage may revolve around Werfen’s data systems, ETL pipelines, and SQL queries.

In some cases for the Data Engineer role, take-home assignments regarding data processing, system architecture, and similar real-scenario problems may be incorporated. Apart from these, your proficiency in programming languages pertinent to data engineering like Python or Java and your understanding of cloud infrastructure may also be assessed during the round.

Onsite Interview Rounds

Followed by a second recruiter call outlining the next stage, you’ll be invited to attend the onsite interview loop. Multiple interview rounds, varying with the role, will be conducted during your day at the Werfen office. Your technical prowess, including programming and data pipeline optimization capabilities, will be evaluated against the finalized candidates throughout these interviews.

If you were assigned take-home exercises, a presentation round may also await you during the onsite interview for the Data Engineer role at Werfen.

Quick Tips For Werfen Data Engineer Interviews

Here are a few tips for preparing for your Data Engineer interview with Werfen:

• Understand Werfen’s Business: Get acquainted with Werfen’s product lines, particularly in diagnostics and healthcare applications. Understanding their business model can help you tailor your answers to fit their needs.
• Be Proficient in Data Engineering: Ensure you're comfortable with ETL processes, data pipeline optimization, and proficiency in SQL and Python or Java. Werfen’s interviews often test these skills extensively.
• Prepare for Behavioral Questions: Werfen values strong interpersonal and communication skills. Prepare to demonstrate your leadership, teamwork, and problem-solving abilities through structured responses to behavioral questions.

Typically, interviews at Werfen vary by role and team, but commonly Data Engineer interviews follow a fairly standardized process across these question topics.

• Write a function calculate_rmse to calculate the root mean squared error of a regression model. The function should take in two lists, one that represents the predictions y_pred and another with the target values y_true.

• Write a query to get the last transaction for each day from a table of bank transactions. Given a table of bank transactions with columns id, transaction_value, and created_at representing the date and time for each transaction, write a query to get the last transaction for each day. The output should include the id of the transaction, datetime of the transaction, and the transaction amount. Order the transactions by datetime.

• Write a function random_key that returns a key at random with a probability proportional to the weights. Given a dictionary with weights, write a function random_key that returns a key at random with a probability proportional to the weights.

• Write a function to get a sample from a standard normal distribution.

• Write a function nearest_entries to find the closest element to N and return k-next and k-previous elements. Given a sorted list of integers ints with no duplicates, write an efficient function nearest_entries that takes in integers N and k and finds the element of the list that is closest to N. Return that element along with the k-next and k-previous elements of the list.

• How would you analyze the churn behavior of users on different Netflix pricing plans? Netflix has two pricing plans: $15/month or $100/year. An executive wants to understand the churn behavior of users on these plans. What metrics, graphs, and models would you build to provide an overarching view of subscription performance?

• How would you predict which merchants DoorDash should acquire in a new market? As a data scientist at DoorDash, you need to build a model to predict which merchants the company should target for acquisition when entering a new market. How would you approach this task?

• How would you value the benefit of keeping a hit TV show on Netflix? Netflix executives are considering renewing a deal with another TV network for exclusive streaming rights to a hit TV series. The show has been on Netflix for a year. How would you approach valuing the benefit of keeping this show on Netflix?

• How would you measure and address the success of LinkedIn’s newsfeed ranking algorithm?

• How would you measure the success of LinkedIn’s newsfeed ranking algorithm?

• If some success metrics for the newsfeed algorithm are improving while others are declining, how would you approach this situation?

• How would you determine the statistical significance of an AB test for a landing page redesign? You want to launch a redesign of a landing page to improve the click-through rate using an AB test. How would you infer if the results of the click-through rate were statistically significant or not?

• How would you explain what a p-value is to someone who is not technical? Explain the concept of a p-value in simple terms to someone without a technical background. Use analogies or everyday examples to make it understandable.

• How many more samples are needed to decrease the margin of error from 3 to 0.3? Given a sample size (n) with a margin of error of 3, calculate the additional number of samples required to reduce the margin of error to 0.3.

• How would you determine if the results of an AB test on a landing page redesign are statistically significant? Describe the process of analyzing AB test results to determine if the observed differences in click-through rates are statistically significant. Include steps such as hypothesis testing and p-value calculation.

• How would you build a model to predict which merchants DoorDash should acquire in a new market? As a data scientist at DoorDash, describe the steps you would take to build a predictive model for identifying which merchants to target for acquisition when entering a new market.

• How would you assign point values to letters in Spanish Scrabble without knowing Spanish? If tasked with building Scrabble for Spanish users and you don't know Spanish, explain your approach to assigning point values to each letter.

What is the average salary for a Data Engineer at Werfen?

Q: What industries does Werfen specialize in? Werfen specializes in developing, manufacturing, and distributing specialized diagnostic instruments, related reagents, automation workcells, and data management solutions for hospitals and independent clinical laboratories. They focus primarily on Hemostasis, Acute Care, and Autoimmunity diagnostics.

Q: What are the key responsibilities for a Data Engineer at Werfen? As a Data Engineer at Werfen, you will perform entry-level work requiring the application of standard techniques and procedures. Key responsibilities include supporting process and production of product lines, contributing to continuous improvement efforts, designing and implementing assembly and test methods, and conducting desk research for competitive intelligence.

Q: What qualifications are required for the Data Engineer position at Werfen? To qualify as a Data Engineer at Werfen, you should be currently pursuing a B.S. in Engineering, Finance, Business, or Marketing with a minimum of two completed college semesters. Strong multitasking abilities and proficiency in tools like Microsoft Word and Excel are essential.

Q: Where are Werfen’s main offices located? Werfen’s North American Commercial Operations, along with their Headquarters and Technology Center for Hemostasis and Acute Care Diagnostics, are based in Bedford, MA. They also have a Technology Center for Hemostasis and Blood Gas Reagents in Orangeburg, NY, and a Technology Center for Whole Blood Hemostasis in San Diego, CA.

Q: How can I prepare for an interview at Werfen? To prepare for an interview at Werfen, research the company thoroughly, practice common interview questions using Interview Query, and review your technical skills. Be ready to discuss your past experiences and how they relate to the position you're applying for.

If you want more insights about the company, check out our main Werfen Interview Guide, where we have covered many interview questions that could be asked. We’ve also created interview guides for other roles, such as software engineer and data analyst, where you can learn more about Werfen’s interview process for different positions.

At Interview Query, we empower you to unlock your interview prowess with a comprehensive toolkit, equipping you with the knowledge, confidence, and strategic guidance to conquer every Werfen data engineer interview question and challenge.

You can check out all our company interview guides for better preparation, and if you have any questions, don’t hesitate to reach out to us.

Good luck with your interview!