How to pass a live coding interview

Live coding is not a take-home. The interviewer is watching how you clarify the prompt, pick an example, choose a data structure, and recover when a test fails. Correctness matters, but a silent, perfect function with no complexity discussion often scores worse than a working brute-force solution you then tighten.

A backend engineer interviewing for an L5 role at a public cloud vendor gets a rate limiter in a shared editor. The interviewer is not waiting for a textbook token bucket on the first compile. They want to hear burst versus steady-state, a sketch of O(1) versus scanning a log, and a failing test written before the happy path. That conversation is the round.

Rounds usually run in CoderPad, CodeSignal, HackerRank, or a shared editor inside Zoom, Google Meet, or Microsoft Teams. Ask about input size, duplicates, and mutation before you type. Restate the output. Then write.

• Clarified constraints before the first line.
• Started with a correct brute-force plan, then one improvement.
• Stated time and space complexity out loud.
• Traced an example and one edge case.
• Recovered from a failed run without going silent.

You worry that talking will slow you down or make you sound unsure. This section gives a narration pattern you can reuse on any shared-editor problem, from the first restatement through the stuck minute. Use it until it is muscle memory, not a script you read.

Before the first line, restate the problem, name constraints, and walk one example by hand. Then say the brute-force idea and its complexity. Only then type. While you type, name the invariant of the loop, not every keystroke. If you freeze, say what you are checking (null input, off-by-one, sorted versus unsorted) instead of going quiet.

• Clarify types, size, and edge cases out loud.
• Offer brute force, then one improvement, then code.
• Trace the example through the finished function.
• Ask for a hint rather than stalling in silence.

A timed dry run where you speak the whole way through is on the mock interview page.

If you share your screen, a window, or a recorded desktop, anything on that display is visible, including a floating overlay. Proctored platforms, lockdown browsers, and company-managed devices are out of scope for any local assistant. Do not treat any tool as invisible in those settings.

SubcueAI ships two live-assist surfaces, and neither joins the call as a meeting bot or injects a content script into the meeting page. The native macOS and Windows desktop app captures system audio plus your mic and shows a floating local overlay that works with desktop meeting clients. The Chromium extension (Chrome and Edge) uses a Side Panel and captures only the meeting tab's audio, the interviewer, never your mic, so it covers browser-tab calls and does not transcribe you. The Firefox build is mock-practice only.

If the overlay sits on a display you are not sharing, the interviewer does not see it. A full-desktop share includes every window on that display. Honest limits for what interviewers can see are collected on the detectability topic page.

Practice the patterns you will actually write under time: arrays and hashes, two pointers, sliding window, binary search, BFS and DFS, heaps, and a basic interval merge. Fluency in your language's hashmap, queue, and sort API matters more than memorizing obscure puzzles. Talk while you solve; mute practice does not transfer.

Do one mock on the same stack you will use live: same language, same editor habits, same meeting client. If the company uses Zoom on the desktop app, rehearse there. If they use Google Meet in a Chrome tab, rehearse with the tab open. Setup for the desktop overlay and the Chrome Side Panel is on the tutorial page.

If you cannot finish the optimal solution, ship a correct brute force, state the bottleneck, and sketch the faster approach. A complete slower answer with a clear faster plan usually beats an unfinished clever idea.