I was referred, and the hiring agent contacted me with bare-bones emails, not much of a hint about preparation except for "look at our product and check the interviewer's profile on LinkedIn".

CAREFUL: if you are referred, it seems like they skip the introductory interview and go directly to technical. Or was it just my interviewer? After all, he did not reveal much consistency in other aspects.

He introduced himself, said it would be 45 minutes, and asked about my experience, but tended to skip unfamiliar technologies. He became more alert when I mentioned Oracle and then...

ADVICE: never take a phone interview on the street or just stepping out of your office. Plan in advance to have a quiet room, enough time, and to be undisturbed.

The interviewer asked me a simple question about trees vs. HashTables. I explained how HashTables work (buckets, then traversing), mentioned O(log n) for trees, and blurted out O(n) for HashTables. The interview stopped right there. I mean, seriously, I've been in engineering for 15+ years. You can guess from my resume the number of interviews passed. Do you really think you have to ask this?

I must say he was polite enough to ask if I had questions. That's good because I figured out I wouldn't regret missing this opportunity:

1. He wasn't positive on Macs for developers.
2. They tend to use Eclipse as an IDE because "they have plugins."
3. They are "not using NoSQL databases because Oracle gives them logging, stats, etc." (and this is for a product that deals with unstructured data (CRM)!!!).

This tells me they are rather a "sandbox" shop in terms of technologies, i.e., they prefer to use what they know versus reaching out and investing in research. Too bad for the engineers.

Q: Explain encapsulation.

Q: Inheritance vs. composition.

Q: What's the difference between a tree and a hash table?