The interviewer opened with, "Do you speak Chinese?" After I said yes, we spoke Chinese for the entire interview. I gave a brief introduction, then we went straight into questions.
Fundamentals / business design
Memory and virtual memory:
Follow-up: What is virtual memory for?
Follow-up: Can virtual memory space (VRAM) be larger than physical memory (RAM)?
The reasoning we discussed: Yes. Virtual memory can swap inactive pages out to disk, using disk space to expand the available virtual address space. Underneath, the memory management unit (MMU) and operating system kernel manage this together.
TCP three-way handshake:
The process and purpose of TCP's three-way handshake.
The key points: The client sends SYN, the server returns SYN-ACK, and the client acknowledges with ACK. The emphasis was on explaining how TCP uses this mechanism to establish a reliable connection and ensure data integrity and ordering.
Evaluating agent metrics:
Scenario: Suppose there are three agents with different levels of reliability. How would you choose precision, recall, or F1-score to evaluate them?
The focus: Analyze the tolerance for false positives and false negatives in different scenarios.
Debugging agent tool calls:
Scenario: When an agent fails or encounters an exception while calling an external tool, how would you design tracing across the whole chain?
The focus: Use trace IDs and span IDs to mark the chain, log inputs and outputs, capture exception status codes, and analyze retries.
Algorithms / LeetCode
Problem description:
Given a directed graph:
Find all paths from a start to an end vertex, or in the graph.
Find all cycles in the graph.
They mainly tested the algorithms. The graph was hard-coded as an adjacency list.
My approach and reasoning:
All paths:
I used DFS with a path stack for backtracking, and got it running successfully.
Finding cycles:
I explained the logic verbally: During DFS, visiting a node already marked as visited in the current recursion stack indicates a cycle. To deduplicate cycles and give them a canonical output form, record only cycles starting from their smallest node.
Then it was Q&A.
Discussion
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