Hello, I'm interested in learning about the focus of Deloitte's second technical interview for candidates applying to IT roles. Specifically, I'm curious if they going deeply into object-oriented programming (OOP) concepts

I don't know. 

But there are two main ways of finding out. 

1. Reach out to the recruiter. 

Ask them to give you an understanding of the structure of the interview. Ask them, for example, about questions from past interviews. Ask them about the presence of OOP concepts. 

They want you to succeed, so even though they're not going to tell you what are the exact questions that will pop up during the interview, they'll tell you as much as they can.

2. Reach out to recent hires. 

Go on LinkedIn and find out who got hired within the last year or so in your target office. Get them on a call and ask for advice on the recruitment process and an understanding of how they prepared in order to be successful. Don't ask questions that would put them in an uncomfortable situation - i.e., anything that would feel like they're giving you an unfair advantage. 

Here's how to find out these candidates via LinkedIn and reach out to them with higher chances of actually getting a response:

• Expert Guide: How To Get Referrals Via LinkedIn?

Best,
Cristian

Most of the people in here are focused on strategy-related interviews. I doubt this is the best type of forum to obtain an answer to that question. I suggest you search within Glassdoor.