Top 20 Interview Questions & Answers for Informatica ETL Developer Roles - 2025

Are you preparing for an interview for an Informatica ETL Developer role? This guide provides a comprehensive list of updated interview questions and answers to help you showcase your technical skills, proficiency in Informatica ETL tools, and problem-solving abilities. These questions cover all key areas of the job and are designed to assess your knowledge of the latest industry practices as of 2025.

General Questions

• 1. What interests you about working as an Informatica ETL Developer?
  Answer: As a data-driven professional, I am fascinated by the potential of Informatica ETL in streamlining and optimizing data management processes for organizations. I am excited about the opportunity to work with a cutting-edge technology and contribute to driving business growth and success.
• 2. What experience do you have with Informatica ETL tools?
  Answer: I have over 3 years of experience working with Informatica ETL tools such as PowerCenter and Cloud. I have successfully designed, developed, and implemented ETL workflows for various clients, including data integration, data warehousing, and data migration projects.
• 3. How do you stay updated with the latest trends and developments in Informatica ETL?
  Answer: I regularly attend webinars and seminars on Informatica ETL, follow industry experts and thought leaders on social media platforms, and read blogs and articles published by Informatica and other reputable sources.
• 4. Tell me about a project where you faced a technical challenge and how did you overcome it?
  Answer: In a recent project, I encountered difficulties in extracting and loading data from a legacy system into a new database due to data duplication and inconsistent data formats. I resolved the issue by writing custom scripts to clean and transform the data before loading it into the target database.
• 5. How do you ensure the quality and accuracy of your ETL processes?
  Answer: I follow a thorough testing and validation process, where I compare the source and target data, fix any data discrepancies, and perform regression testing to ensure the accuracy and integrity of the data. I also document my changes to maintain a record of the ETL process.

Technical Skills & Experience

• 6. What is the difference between a mapping and a workflow in Informatica?
  Answer: A mapping is a visual representation of the flow of data from source to target, while a workflow is a set of instructions that specify the execution of tasks within the mapping. In other words, a mapping defines the data transformation logic, and a workflow defines the execution of the mapping.
• 7. How do you handle large volumes of data in Informatica?
  Answer: Informatica has a feature called partitioning, which allows for parallel processing of data to optimize performance. We can also use pushdown optimization to transfer data processing to the source or target database, reducing the data processing load on Informatica.
• 8. What is a lookup transformation in Informatica, and how is it different from a joiner transformation?
  Answer: A lookup transformation looks up data from a source or target table based on a lookup condition and returns the requested data to the mapping. On the other hand, a joiner transformation joins data from two sources based on a common key and combines the data into a single dataset.
• 9. How do you deal with data errors or missing data in an ETL process?
  Answer: I use conditional statements and reject links in the mapping to handle data errors and redirect the rejected data to a file for further analysis. I also ensure proper data cleansing and validation rules are in place to prevent errors and missing data.
• 10. What is a reusable transformation in Informatica and how do you create one?
  Answer: A reusable transformation is a mapping that can be used in multiple mappings without having to recreate it each time. To create a reusable transformation, we can select the "Reusable" option in the transformation properties and save it in a shared folder for easy access.

Decision-Making Skills

• 11. How do you prioritize and manage multiple ETL projects at once?
  Answer: I follow a project management approach and use tools like Trello or Asana to track project timelines, tasks, and progress. I also maintain clear communication with stakeholders to align expectations and prioritize tasks based on urgency and business needs.
• 12. How do you decide on the data model for a data warehousing project?
  Answer: Before deciding on a data model, I gather requirements from stakeholders, analyze the data sources and target system, and consider the performance and scalability requirements of the project. Based on this information, I select an appropriate data model that can efficiently store and manage the data, such as a star schema or a snowflake schema.
• 13. Can you walk me through your problem-solving approach when faced with unexpected errors or performance issues in an ETL process?
  Answer: When facing unexpected errors or performance issues in an ETL process, my first step is to identify the root cause by checking log files, reviewing the mapping or workflow, and testing different scenarios. Once I have a clear understanding of the issue, I implement the necessary fixes and run multiple tests to ensure the issue is resolved.
• 14. How do you ensure the security of sensitive data in an ETL process?
  Answer: I follow data encryption and masking techniques to secure sensitive data in transit and at rest. Additionally, I limit access to sensitive data in the ETL process by setting permissions for specific users, establishing data security rules, and constantly monitoring access logs.
• 15. Can you share a project where you had to make a tough decision, and how did you handle it?
  Answer: In a recent project, I had to make a decision to change the entire ETL process due to a change in data source structure. I organized a meeting with stakeholders and explained the reasons for the decision and the potential impact on the project. With their approval and support, I made the necessary changes, and the project was successfully completed within the given timeline.

Cultural Fit

• 16. How do you handle conflicts or disagreements with team members?
  Answer: I believe in open communication and actively listening to understand different perspectives in cases of conflicts or disagreements. I try to find a middle ground by discussing possible solutions and compromising when necessary. I also ensure to maintain a positive and respectful attitude towards my team members.
• 17. How do you handle working under pressure or tight deadlines?
  Answer: Working under pressure or tight deadlines is part of the job in the technology industry. I am experienced in managing my time effectively and setting realistic timelines for tasks. If necessary, I prioritize tasks and communicate with my team to delegate tasks and ensure we meet the deadline without compromising on quality.
• 18. How do you keep yourself motivated and productive at work?
  Answer: I am passionate about my work and always strive to deliver my best. I also actively seek new challenges and learning opportunities to keep myself engaged and motivated. Setting achievable goals and taking short breaks to recharge also helps me stay productive throughout the day.
• 19. Can you explain a time when you had to adapt to a change in a project's scope or requirements?
  Answer: In a previous project, I had to adapt to a change in the data validation process due to an increase in the data volume. I re-evaluated the existing validation approach and made adjustments to account for the increased data, which helped us meet the project's evolving requirements.
• 20. What would you say is your greatest strength that would make you an asset to our team?
  Answer: My greatest strength is my ability to quickly understand complex concepts and use my technical expertise to provide efficient and effective solutions. I am also a team player and thrive in collaborative work environments. I believe these qualities would make me a valuable asset to your team.