I am currently a Data Engineer with 3 years of experience, specializing in SQL, Python, PySpark, Azure, ETL, Snowflake, and DBT, primarily in the Ecommerce, Healthcare, and Consumer tech domains. My current salary is less than 12 LPA, and I'm looking to switch jobs due to low pay and a poor work culture. I want to gain exposure to larger scale projects. I've attended a few interviews but haven't been successful because my preparation wasn't sufficient. I'm not applying aggressively yet, but I'm seeking advice on how to better prepare for interviews, as I'm aiming for a salary in the range of 17 to 20 LPA. Any tips on focusing my preparation, particularly on system design and SQL optimization, would be greatly appreciated.