To answer technical questions in an AI voice interview, explain each idea in four spoken steps: define the term in one sentence, explain how it works, name the trade-off or when you wouldn't use it, and prove it with an example from your own work. With no whiteboard and no nodding interviewer, the transcript of what you said is the main evidence, so say symbols, numbers and names clearly, signpost your structure, and never point at "this part here." AI interviewers often follow up to test how deep your knowledge goes, so only bring up what you can explain.
What technical AI voice interviews ask
AI interviewers increasingly handle the first technical conversation. As of October 2026:
- Mercor's AI interview guide says some of its interviews are technical and require deep discussion of your prior experience, and that the AI transcribes your responses to evaluate them.
- micro1 tells candidates for some technical roles to expect "deep technical questions" testing architecture, problem-solving and code reasoning.
- HireVue says its AI Interviewer asks probing follow-up questions and can score skill questions on a custom 1-to-5 rubric, with recruiters making the final call.
The questions themselves tend to fall into five types. Each needs a slightly different spoken shape.
| Question type | Example (ours) | Answer shape | Transcript pitfall |
|---|---|---|---|
| Concept | "What is a database index?" | Define, how it works, trade-off, your example | Vague words like "it makes things faster" |
| Comparison | "When would you pick a queue over direct API calls?" | One or two criteria, then a clear recommendation | Listing features with no choice at the end |
| Design | "How would you design a URL shortener?" | Requirements, main components, data flow, the bottleneck | Talking as if drawing: "this box connects here" |
| Debugging | "Latency doubled after a deploy. What do you check?" | Ordered steps, each with a reason | Jumping to a fix before diagnosing |
| Experience deep-dive | "Walk me through a system you built." | Goal, design, your part, result, what you'd change | "We" all the way through, no "I" |
For design questions, the system design cheat sheet is a quick refresher on components and capacity math.
The four-step spoken answer: define, explain, trade off, prove
- Define in one sentence. "A database index is a separate data structure that lets the database find rows without scanning the whole table." This is the line a scorer looks for first, so make it complete and precise.
- Explain how it works. Two or three sentences on the mechanism, in plain words, as if to a colleague from another team: "Most indexes are B-trees, so a lookup takes a few hops instead of reading every row."
- Name the trade-off. This is where depth shows. "The cost is slower writes, because every insert updates the index too, plus extra storage."
- Prove it from your work. One concrete example with a number if you have one: "On our orders table, adding a composite index on customer and date took a report from about eight seconds to under one."
Then stop. If the AI wants more, it will usually ask, and a follow-up you can answer well is worth more than a longer first answer. Our guide to AI interviewer follow-up questions shows how to prepare that second layer of detail.
How to say technical things so the transcript gets them right
Speech-to-text handles everyday words well, but technical speech is full of symbols, acronyms and product names. A few habits keep your meaning intact:
- Expand acronyms once. "CDN, a content delivery network," then "CDN" after that.
- Say symbols as words. "O of n log n," "greater than or equal to," "a hash map from user ID to session."
- Name tools precisely and consistently. Pick one name, such as "PostgreSQL," and stick with it instead of switching between "Postgres," "the DB" and "that database."
- Give numbers with units. "About 200 milliseconds at the 95th percentile," not "like two hundred."
- Signpost the structure. "Three parts: storage, the API and caching. First, storage." It works as the whiteboard you don't have.
- Buy thinking time out loud. Mercor notes that extended silences may trigger the AI to interject, and that you can ask the AI to repeat or clarify a question. "Let me think about that for a moment" keeps the turn yours.
More on this in structuring answers for AI transcription and how AI interviewers handle pauses.
Example answer and a before-and-after rewrite
Question: "What is a database index, and when would you not add one?" The answer below is an example we wrote; use your own projects and numbers.
Example answer: "A database index is a separate structure that lets the database find rows without scanning the whole table, a bit like the index at the back of a book. Most are B-trees, so a lookup takes a few steps instead of reading every row. I wouldn't add one in two cases. First, on a table that's written far more than it's read, like an event log, because every insert also has to update the index. Second, on a column with very few distinct values, like a true-or-false flag, because the index barely narrows the search. In my last role, our reporting query on the orders table took about eight seconds. I added a composite index on customer ID and order date, it dropped to under a second, and I checked that insert times on that table didn't noticeably change."
| Version | Answer (example) | What's missing or present |
|---|---|---|
| Before | "An index makes queries faster. You put them on columns you search a lot. Too many can be bad, though, so you have to be careful. We used them a lot at my last job." | No definition of the mechanism, a vague trade-off, no "when not," and "we" with no specific example |
| After | "An index is a separate structure, usually a B-tree, that finds rows without a full scan. I'd skip it on write-heavy tables and low-variety columns. I added one to our orders table and a report went from about eight seconds to under one." | Definition, mechanism, two clear "when not" cases and a personal, measured example |
When you don't know the answer
Silence or a guess presented as fact both read badly in a transcript. Instead, show how you reason:
- Say what you do know. "I haven't used Kafka in production, but I've used RabbitMQ, so let me compare from there."
- State your assumption. "I'd assume reads outnumber writes about ten to one; if that's wrong, the design changes."
- Reason from first principles. Walk through what the system has to do and where it would break.
- Say how you'd find out. "I'd check the query plan before adding anything."
Our guide on what to do if you don't know the answer has more phrases for this.
Practice with a technical mock interview
- List ten concepts from the job description and draft a one-sentence definition and one trade-off for each.
- Run a scored technical mock. Our free AI interview assistant includes a Mock Interview mode that builds questions from your résumé and the job description. You choose the level, 3, 5 or 8 questions, and the mix (behavioral, technical, system design, coding), plus an optional focus such as databases. It reads each question aloud, scores your spoken answer out of 10 with what to fix and a model answer, then gives you a report card. The free plan includes 15 minutes every day.
- Answer your lowest score again with the four steps: define, explain, trade off, prove.
- Drill single questions in the browser. The demo at /try has 145 real interview questions across 10 tracks, including system design, SQL, DevOps and frontend, graded by AI.
Take the assessment yourself and follow the employer's rules — use CoPilot Interview to practice beforehand. For the wider picture of the role, see AI interviews for software engineers and our technical phone screen guide.
Practice explaining it out loud
Mock Interview asks technical and system design questions aloud, scores each spoken answer out of 10 and shows what to fix, so your definitions and trade-offs come out clean on the day.
Try a free AI mock interviewFAQ
Do AI voice interviews ask technical questions?
Many do, especially for engineering and data roles. As of October 2026, Mercor says some of its AI interviews are technical and dig into your prior experience, and micro1 tells some technical candidates to expect questions on architecture, problem-solving and code reasoning. The mix depends on the employer and the role.
How detailed should a technical answer be?
Detailed enough to define the idea, explain how it works, name one trade-off and give one example from your work. That usually takes one to two minutes. Stop there and let follow-up questions take you deeper, rather than front-loading everything.
What if the AI mishears a technical term?
Reduce the chance first: expand acronyms once, say symbols as words and use one consistent name for each tool. If you realize it misunderstood you, say so plainly and restate the key sentence. Ask it to repeat or clarify the question whenever you need to.
Can I ask the AI interviewer to repeat a question?
Often, yes. Mercor's candidate guide, for example, says you can ask the AI to repeat or clarify a question. Other platforms differ, so check the instructions in your invitation.
Should I use technical jargon in an AI interview?
Use the correct technical terms, because they show you know the field and often match the job description, but define each one briefly the first time. Jargon without explanation is harder to follow and invites a follow-up you may not want.
How do I prepare for technical follow-up questions?
For every term or project you plan to mention, prepare one level deeper: why you chose it, what the alternative was and what went wrong. Practice by asking yourself "why?" and "how exactly?" after each answer and answering out loud.