How to pass the live coding round in technical interviews

Four years ago I got my first job and then switched once; now I’m preparing to move again. This time around, two things stand out: finding a company that fits my experience and vision matters more than it did back then, and live coding has become the hurdle I need to clear. I’ve had three onsite interviews so far—and failed all three.

Those interviews were mostly live coding plus CS questions about my projects. Thanks to the tradeoffs I’d already thought through while building things, the CS part was manageable. The problem was live coding. A typical loop was one hour of live coding followed by one hour of CS; struggling in the first hour threw off the rest of the interview.

So I’ve paused applying for now. I’m putting together a plan to get through the live coding round and planning to focus on it for about a month.

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What do interviewers actually care about in live coding?

Before locking in a plan, I tried to spell out what interviewers are really evaluating during live coding.

1. Problem analysis — Do you correctly understand the requirements and constraints?
2. Algorithm and data structure choice — Do you weigh tradeoffs between options? Do you consider alternatives?
3. Time and space complexity — Can you explain the complexity of your approach?
4. Edge cases — Do you identify and validate extreme inputs and corner cases?
5. Code quality — Are naming, error handling, and structure at a level you’d be okay with in production?

Bottom line: how you explain your thinking matters more than the code itself.

So I’m using a practice template to get better at communicating that thinking clearly:

• Approach
• Time and space complexity
• Alternative approaches
• Edge cases

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What to prepare: six categories are enough

For the kind of live coding I’ve seen, six categories covered systematically are enough.

1. Array / String

• Two pointers
• Sliding window
• Prefix sum

2. Hash Map / Set

• Frequency counting
• Deduplication
• Lookup optimization

3. Stack / Queue

• Parenthesis / bracket problems
• Monotonic stack
• BFS with a queue

4. Linked List

• Reversal
• Cycle detection (Floyd’s algorithm)

5. Tree / Binary Tree

• DFS / BFS
• Depth and height
• Lowest common ancestor

6. Graph (basics)

• BFS / DFS
• Visited tracking
• Directed vs undirected

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Practice plan

• LeetCode: focus on Medium, use Easy to solidify concepts.
• Goal: practice until I can solve and explain each category in a live coding setting without getting stuck.