Public Interest/Non-Profit Interviewing
As a lawyer seeking to move from a big law firm to the public interest/non-profit arena, you must be able to articulate very clearly and convincingly why you want to make this shift. You also must show that you understand and can intelligently discuss the issues facing that organization's constituents (e.g., slumlords, immigration issues, child welfare issues). Another important point for you to make during your interview is that a massive pay cut will not be a problem.
The main traits and skills desired by public interest organizations can be found on the Public Interest/Non-Profit page of this site. You should expect to be asked some behavioral interview questions about those traits (e.g., for examples of times that you worked well under pressure, worked well with limited resources, had a difficult client, etc.). You can find many examples of such behavioral questions on the Interview Question Types page of this site, in addition to the more specific questions that can be found below.