I have extensive experience with ETL tools such as Informatica, Talend, and SSIS. In my previous role, I used Informatica to design and implement ETL workflows for data integration, ensuring data accuracy and performance. I also worked with Talend for cloud-based data pipelines and SSIS for on-premise data warehousing. My expertise includes creating mappings, transformations, and scheduling jobs to automate data extraction, loading, and processing.

I ensure data quality by implementing validation rules, data cleansing, and error handling mechanisms. For example, I use checksums, data profiling, and deduplication techniques to identify and resolve inconsistencies. I also log errors and exceptions for troubleshooting. Additionally, I collaborate with stakeholders to define data quality standards and perform regular audits to maintain accuracy and reliability throughout the ETL pipeline.

In one project, I faced performance issues with a large dataset during extraction. I resolved this by optimizing SQL queries, partitioning data, and using incremental loading techniques. I also implemented parallel processing to reduce runtime. By collaborating with the database team to fine-tune indexes and storage, I improved the overall efficiency of the ETL process, ensuring timely data delivery without compromising quality.

I handle schema changes by maintaining version control and documenting modifications. I use tools like Git for tracking changes and ensure backward compatibility. When a schema change occurs, I update ETL mappings, transformations, and workflows accordingly. I also communicate with stakeholders to minimize disruptions and perform thorough testing to validate the changes before deploying them to production.

I optimize ETL performance by using techniques like indexing, partitioning, and parallel processing. I also minimize data movement by staging data efficiently and leveraging in-memory processing. Additionally, I monitor system resources and fine-tune configurations to reduce bottlenecks. Regular performance testing and profiling help identify areas for improvement, ensuring the ETL process runs smoothly and meets SLAs.