I have 7+ years of experience (mostly writing performant math libraries) and I am decent at algo, data-structures and LLD questions as my current job involves all of these. However, I have been developing single node application and my current job does not involve any large system. So I don't know how to prepare for system design interviews. I am reading up all the commonly recommended material (Designing Data Intensive Applications, etc), but I feel I still need some hands on experience to confidently tackle such questions.

• Please guide me on how I can get some practical system design experience. And how should I prepare for DS interviews for tech companies given my current situation ?
• Was anyone in a similar situation as me ? How did you overcome it to get your dream job ?
• What sort of companies would I have a better chance of getting into, given my experience ?

Appreciate your help!