In this article
How this page is organized
The questions below are grouped by what you face on the day: the format, solving a problem aloud, the pressure of being watched, and the kinds of question you meet. Use it with the coding interview guide, which teaches the problem patterns; this page covers the in-person setting around them. Each entry gives a short answer, a line on why it is asked, and a place to read more. Where a source describes one employer's process, the answer says so, because loops differ between companies.
The format
What is a face-to-face technical interview?
A face-to-face technical interview is a real-time problem-solving assessment in which you solve a technical problem in front of an interviewer, often writing code or diagrams on a whiteboard while onsite (Holloway Guide, August 2022). A similar interview can be done in person with pen and paper. The interviewer watches and talks with you as you work, so communication is part of the task.
Why it is asked: employers want to see how you reason with another person present. Read the full explanation: Holloway Guide, whiteboard interviews.
Is a face-to-face technical interview always on a whiteboard?
No. The Holloway Guide says hands-on coding interviews include all formats where a candidate uses a computer and not a whiteboard, and that paper is possible too. A whiteboard gives no compiler, editor or reference material, and it favors people with fresh memory of a language. Ask the recruiter which format to expect, then practice in that format.
Why it is asked: it is a logistics question, but the answer changes how you prepare. Read the full explanation: Holloway Guide, whiteboard interviews.
Who will interview me, and what will they ask?
It depends on the employer. Salesforce's own candidate guide says that on the day you meet at least four people: three engineers and a lunch with the hiring manager. Each asks both behavioral and technical questions, and for the technical part you should expect a whiteboard with every person (Salesforce Trailhead). That is one employer's process, not a rule for all.
Why it is asked: knowing the shape of the day lets you pace your energy. Read the full explanation: Salesforce Trailhead, onsite interview.
What are interviewers actually scoring?
Google's structured-interviewing guide says that for problem-solving questions, interviewers may not be looking to assess a correct answer but "want to judge the analytical thought process" used to explore, define and offer a solution (Google re:Work, March 2026). It lists role-related knowledge, problem solving and leadership as categories. In a coding round the working solution still counts; narrating your reasoning lets the interviewer give credit for the path too.
Why it is asked: candidates who think only the final answer counts stop talking at the wrong moment. Read the full explanation: Google re:Work, structured interviewing.
Knowing it is half the job. Saying it is the other half.
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Start Free Trial →Solving a problem aloud
A strong round follows one order: clarify the question before writing code, then plan, code and test by hand, narrating each step while you plan, code and test.
Text description of the diagram
- Clarify the question before writing code.
- Narrate each step while you plan, code and test.
How should I start when the interviewer gives me a problem?
Clarify the question before writing code. Restate the problem in your own words, ask about the input and its limits, and name one or two edge cases such as an empty input. Salesforce's guide tells candidates to ask the interviewers for clarification if they do not understand a question. Then say your plan in a sentence before you touch the board.
Why it is asked: asking good questions is itself a signal, and it prevents solving the wrong problem. Read the full explanation: Coding interview guide.
How do I think aloud without rambling?
Salesforce advises practicing thinking out loud while solving unfamiliar problems, so that you can narrate your decisions. A simple pattern keeps it short: say what you are about to do, do it, then say what you learned. Name your choices ("a dictionary, because I need fast lookups") rather than describing every keystroke. Pause in silence only briefly, and say when you are thinking.
Why it is asked: the interviewer can only score the reasoning they can hear. Read the full explanation: Salesforce Trailhead, onsite interview.
What if I am stuck or do not know the answer?
Say what you do know, then reduce the problem. Solve a smaller version, write the plain brute-force approach and state its cost, then improve it. Google's guide says that for problem-solving questions interviewers may judge the thought process rather than only a correct answer; in a coding round the working solution still counts, but a visible path from a slow solution to a better one lets the interviewer credit your reasoning too, which silence does not. If you are truly stuck, ask for a hint and say what the hint changed.
Why it is asked: interviewers see how you behave when the problem is hard, which is common at work. Read the full explanation: Google re:Work, structured interviewing.
How do I write code without a compiler or editor?
A whiteboard has no compiler, editor or reference material, so you replace the tools with habits. Keep the code short and readable, use clear variable names, and say when you are unsure of an exact library call and what you would look up. Then test by hand: pick a small input, step through your code line by line, and write the values as you go.
Why it is asked: it shows whether you can reason about your own code without running it. Read the full explanation: Holloway Guide, whiteboard interviews.
How would you find the first non-repeating character in a string?
Count every character in one pass, then scan the string again and return the first character whose count is one. For "swiss" the answer is "w", at index 1.1 Say this aloud: "I count first because a character can only be called non-repeating after I have seen the whole string."
def first_unique(s):
counts = {}
for ch in s:
counts[ch] = counts.get(ch, 0) + 1
for i, ch in enumerate(s):
if counts[ch] == 1:
return i
return NoneWhy it is asked: it tests a dictionary, two passes and an edge case (no such character) in a few lines. Read the full explanation: Coding interview guide.
How do I state time and space complexity?
Time complexity is how the number of steps grows as the input grows; space complexity is how the extra memory grows. The counting solution above reads the string twice, so its time grows in proportion to the length, written O(n), and its extra space grows with the number of distinct characters. That is at most two passes, so at most 2n = 10 steps for a five-letter string (on "swiss" the second pass stops at index 1, so it takes 7). Checking each character against every other character takes up to n(n−1) = 20 comparisons, which grows as O(n²) (illustrative step counts).1
Why it is asked: a correct answer with no cost analysis reads as incomplete. Read the full explanation: Coding interview guide.
The pressure of being watched
Why is a technical interview harder when someone watches?
In a randomized controlled trial with 48 computer science students, performance was reduced by more than half simply by being watched by an interviewer, and stress and cognitive load were significantly higher than in a private setting (NC State, July 2020). Private participants did not explain aloud. The sample was small, so treat it as a signal, not a law.
Why it is asked: candidates often assume nerves are a personal failing; the study suggests the setting itself adds load. Read the full explanation: NC State University News.
How do I handle nerves in a face-to-face technical interview?
Practice under the condition that causes the stress: being watched while explaining. Solve problems out loud in front of a friend or a camera, on paper or a whiteboard, until narrating feels normal. In the round, slow your first sentence, restate the problem, and write a small example before coding. These are habits, not a cure; the study above shows the effect is real, not that any one trick removes it.
Why it is asked: interviewers see how you act under mild pressure, and preparation reduces the surprise. Read the full explanation: Coding interview guide.
The kinds of question you meet
Will I get behavioral questions in a technical round?
Possibly. Salesforce's guide says each interviewer will ask both behavioral and technical questions. Google describes behavioral questions as asking about prior achievements, such as "Tell me about a time…". Prepare a few real stories with the situation, what you did and the result, and be ready to name your own part in a team effort.
Why it is asked: technical skill is judged together with how you work with others. Read the full explanation: Salesforce Trailhead, onsite interview.
How do I answer a hypothetical question such as "What would you do if…"?
Google's guide describes hypothetical questions as presenting a job-related situation, with "What would you do if…?" as the example. Answer by reasoning: restate the situation, list what you would need to find out, give your first step and say what could go wrong. State your assumptions out loud, and name the trade-off between your option and the next best one.
Why it is asked: it shows how you decide when no code can settle the question. Read the full explanation: Google re:Work, structured interviewing.
What does a structured interview mean for my answers?
A structured interview is one in which every candidate gets the same questions, graded on an identical scale against predetermined qualifications. Google says it uses this approach, with vetted questions, recorded feedback, rubrics that define outstanding, solid, borderline and poor responses, and interviewer calibration. Not every company does. If yours does, cover every part of the question explicitly, because the grader works down a list.
Why it is asked: knowing there is a rubric explains why interviewers keep prompting for reasons and trade-offs. Read the full explanation: Google re:Work, structured interviewing.
What technical questions should I expect for my language or role?
That depends on the role, and the questions are set by the team, not by the format. Prepare language and role topics separately from the in-person method above. For a language, see JavaScript interview questions, Java interview questions, React interview questions or the comparison of TypeScript and JavaScript. For wider roles, see full stack developer questions and the quality assurance (QA) role in interview questions for QA.
Why it is asked: the format is shared, but the content is role-specific. Read the full explanation: Coding interview guide.
Technical questions you may be asked in person
The questions below are the kinds candidates report meeting in person; they are written in our own words, and no company is named as asking them.
Walk me through a project you built and the hardest decision in it
Pick one project you know well. Say the goal, your own part, and the one decision with a real alternative, for example a data store or a design you rejected. Explain what you weighed, what you chose and what you would change now. Expect follow-up questions on any detail you mention, so include only what you can defend.
Why it is asked: it shows depth of ownership and honest trade-off thinking. Read the full explanation: full stack developer interview questions.
Reverse a linked list on the whiteboard
Walk the list once and keep three references: the previous node, the current node and the next node. At each node, save the next one, point the current node back at the previous one, then move all three forward. When the current node is empty, the previous node is the new head. Test on an empty list and a one-node list.
Why it is asked: it checks careful pointer handling and edge cases. Read the full explanation: Coding interview guide.
What is the difference between a process and a thread?
A process is a running program with its own memory space. A thread is a unit of execution inside a process, and the threads of one process share its memory. Sharing makes threads cheap to create and to communicate between, but it also allows data races, so shared data needs locks or other coordination.
Why it is asked: it tests operating-system basics that explain concurrency bugs. Read the full explanation: solution architect interview questions.
How would you find duplicates in an array?
The simple way is a set: walk the array, and if a value is already in the set, report it; otherwise add it. This takes time proportional to the length and extra space for the set. If extra space is not allowed, sort first and compare neighbors, which costs more time. State both options and the trade-off.
Why it is asked: it separates a brute-force answer from one that names a cost trade-off. Read the full explanation: Coding interview guide.
Explain how a hash map works
A hash map turns each key into a number with a hash function and uses that number to choose a bucket, so a lookup goes straight to one place instead of scanning. Two keys can land in the same bucket, called a collision, which the map handles by chaining entries or probing for a free slot. Lookups are fast on average but can degrade when many keys collide.
Why it is asked: dictionaries sit under many solutions, and interviewers want to know you understand their cost. Read the full explanation: Coding interview guide.
Debug this snippet with me
Read the code aloud first and say what you think it should do. Then run a small input through it by hand, writing the variable values, until the output differs from what you expect. Name the line where it goes wrong, give the fix, and say how you would test it. Do not guess changes silently.
Why it is asked: it shows how you find faults in code you did not write. Read the full explanation: interview questions for QA.
How to prepare
How do I prepare for a face-to-face technical interview?
Ask the recruiter for the format, then rehearse that format: solve problems aloud on paper or a whiteboard in front of someone. Learn the common patterns, practice stating time and space complexity, and test by hand on a small input. Prepare a few project stories and the language or role topics of the job.
Why it is asked: candidates want one plan instead of scattered advice. Read the full explanation: Coding interview guide.
Follow-up questions
How long is a face-to-face technical interview?
It varies by employer and by round. Salesforce describes a day of four interviews, three with engineers and a lunch with the hiring manager. Ask the recruiter for the schedule, the number of rounds and the format of each.
Are in-person technical interviews harder than remote ones?
Nothing cited here compares the two directly: the NC State study compared a watched whiteboard with a private one, not in-person with remote. What it does suggest is that being watched and explaining at the same time raises stress, so rehearse that situation in whichever format you expect.
Can I bring notes or use my own laptop?
It depends on the employer and the format. A whiteboard setting, as the Holloway Guide describes it, has no compiler, editor or reference material, while hands-on formats use a computer. Ask the recruiter in advance rather than assuming.
What should I practice first?
Start with the method: clarify, plan, code, test by hand and explain, all aloud. Then practice the patterns in the coding interview guide, and add the language or role pages above once the routine feels natural.
- A face-to-face technical interview is real-time problem solving with an interviewer watching, on a whiteboard, paper or a computer.
- For problem-solving questions, some interviewers judge the thought process, so clarify, plan and narrate each step.
- With no compiler on a whiteboard, test your code by hand on a small input.
- State time and space complexity after every solution.
- Being watched raises stress in a small study, so rehearse out loud in front of someone.
- Formats and loops differ by employer; ask the recruiter what to expect.
Sources
- Tech Sector Job Interviews Assess Anxiety, Not Software Skills (NC State University News) — NC State University, 1 Jul 2020
- Whiteboard Interviews (The Holloway Guide to Technical Recruiting and Hiring) — Holloway, 24 Aug 2022
- Own Your Onsite Interview (Salesforce Trailhead) — Salesforce, 26 Oct 2026
- A guide to structured interviewing for better hiring practices (Google re:Work) — Google re:Work, 1 Mar 2026
