How to Use LastRound AI: A Practical Setup and Interview Guide (2026)

The single biggest mistake with any interview copilot is installing it the night before an interview that matters. Used cold, these tools make most people sound worse — they read, they pause in the wrong places, they lose the thread of their own answer. Used with a few hours of practice behind you, they help.

This guide covers getting LastRound AI set up properly and, more importantly, the habits that decide whether it helps or hurts.

Before you start: pick the right plan

The free tier gives you 15 credits a month with no card required, which is enough to test the setup and run a few practice sessions. Paid tiers start at $19/month for 120 credits, with $49 and $99 tiers above that for heavier use. Credits are consumed per session, so if you are mid-search with several interviews a week, size the plan against your busiest week rather than your average.

Setup in under five minutes

1. Install the desktop app

The copilot needs system audio access to hear the interviewer — on macOS that goes through Core Audio taps, on Windows through WASAPI loopback. Grant the audio and screen permissions when prompted. This is the step most likely to break after an OS update, so re-check it if things stop working.

2. Configure your microphone

Two separate audio paths matter: your mic (what the interviewer hears) and system audio (what the copilot hears). Test both. The most common failure is the copilot transcribing your own voice instead of the interviewer's, which produces useless suggestions.

3. Position the overlay

Put it as close to your webcam as possible. The further your eyes travel from the camera, the more obviously you are reading. Directly under the camera is ideal — small eye movements read as thinking, large ones read as looking something up.

4. Run a test interview

Do not skip this. Run a mock interview end to end before any real call. You are testing your own behaviour as much as the software.

Technical rounds

Data structures and algorithms

Use it for approach, not code. Ask yourself what the suggestion is proposing, then narrate that approach in your own words before writing anything. Interviewers care far more about how you reason toward a solution than whether you produce optimal code silently.

System design

This is where a copilot is most useful, because system design rewards breadth — remembering to mention caching, sharding, failure modes, monitoring. Treat suggestions as a checklist prompting what you have forgotten, not a script to recite.

Coding platforms

CodeSignal and HackerRank are supported. Test the overlay on the actual platform before the interview, because shared-editor environments behave differently from a plain video call.

Behavioural rounds

Counter-intuitively, this is where a copilot helps least and hurts most. Behavioural answers depend on specific things that happened to you, and generic AI-shaped answers are transparently generic to anyone who interviews for a living.

Use it for structure, not content. If the suggestion reminds you to frame something as situation-task-action-result, good. If you are reading a story that did not happen to you, the interviewer will find out during follow-ups — and follow-ups are exactly where invented answers fall apart.

Better preparation: write out six real stories beforehand covering conflict, failure, leadership, ambiguity, influence and a proud achievement. Most behavioural questions map onto one of those.

The habits that actually matter

• Pause deliberately. "Let me think about that for a second" buys you two seconds and sounds considered rather than blank.
• Glance, do not read. Take the shape of the suggestion, then look back at the camera and say it your way.
• Ignore most suggestions. The best users take one idea in four. Trying to use everything is what makes people sound robotic.
• Never paste verbatim. Your own phrasing is always better than fluent text that does not sound like you.
• Expect follow-ups. Anything you claim, you will be asked about. Do not claim what you cannot defend.

What not to do

Do not use it as a substitute for preparation — it amplifies what you know and cannot manufacture knowledge you lack. Do not stare off-camera. Do not let it run during small talk, where suggestions are useless and distracting. And do not assume the overlay is invisible on a screen share without checking: start a call with a second account, share your screen, and look. Verify that yourself for any vendor.

A pre-interview routine

1. The day before: read the company insights page for round structure and salary bands, and re-read your own resume.
2. One hour before: run a short mock session on the same question type.
3. Ten minutes before: test audio, check overlay placement, close everything else.
4. During: camera first, overlay second.

The part worth being honest about

Two things are true at once. These tools genuinely help people who know their material but freeze under pressure, who are interviewing in a second language, or who have a disability that makes real-time verbal processing harder. That is a real accessibility case and it deserves better than the reflexive sneering it usually gets.

At the same time: some employers explicitly prohibit AI assistance during interviews, and some platforms look for it. Read the terms you agreed to when you accepted the interview. The risk sits with you, not with the vendor selling the tool — and that includes us.

Nobody disputes the practice side, though. Mock interviews, resume scoring, company research and structured preparation break no rules anywhere, and that is where most of the actual improvement comes from. A copilot cannot rescue an answer you have never thought about. It can only help you deliver one you already have.

Prepared candidates who use a copilot to sharpen what they already know do well. Unprepared candidates using it as a crutch get found out in the follow-up questions. Start with practice, and treat the live copilot as a safety net rather than a plan.