Ampersand Solutions Group · Software Engineer
Updated · 2026-10-02

Ampersand Solutions Group Software Engineer
Interview Guide

THE 60-SECOND BRIEF

Ampersand Solutions Group is described by candidates as a company that writes software for the defense sector. The projects reported for Software Engineers range from radar systems to full-stack development. The topic tags attached to this role are Software Engineering, Verification & Validation (V&V), Independent Verification (IV), Independent Validation (IVa) and Radar Software Engineering. In practice, the role described is hands-on engineering: designing, coding and testing software against specifications, working with product management, quality assurance and operations colleagues, and taking part in code reviews and design discussions. Choose projects where you tested or verified your work, since V&V is a reported topic.

This guide is for software engineers preparing for the Ampersand Solutions Group Software Engineer loop. Candidates describe the typical profile as a computer science or related degree with roughly 2 to 5 years of development experience. Java, C++ and Python are the languages listed as examples, and cloud platforms, DevOps, Agile and cybersecurity are listed as extras. It covers the three reported rounds, the fourteen reported questions (languages and tooling, lifecycle, design, troubleshooting, ambiguity, leadership, conflict, motivation, string reversal, graph search and dynamic programming), and a plan for preparing all of them, including a security task for the code-quality answer.

Candidates report three rounds over roughly 3 to 5 weeks: Initial Screening, Technical Assessment and Behavioral Interview. The reported questions are a mix of open technical discussion, short coding and algorithm questions, and behavioral prompts.

Software EngineeringVerification & Validation (V&V)Independent Verification (IV)

29 min read

Browse Software Engineer questions

See the practice prompts

16Practice promptsAcross five skill areas

The reported topics point to a role where building software and proving it works go together. V&V, IV, IVa and radar software engineering appear as reported topics next to software engineering. For you, that means three things. First, pick project examples in which you wrote or reviewed tests, traced a defect to its cause, or checked behavior against a requirement. Second, be ready to say what verification means (does the build match the specification) and what validation means (does it meet the real need). Third, be ready to explain the word Independent in those two topics. In general usage it means the checking is done by a group separate from the developers, which reviews requirements, design and test artifacts, traces requirements to tests, and witnesses or re-runs tests. Since radar systems are among the reported projects, also prepare one project story about a time, memory or data-volume constraint you worked within.

The reported questions are mostly open-ended. Several ask you to explain your own experience: which languages you are proficient in and which you prefer, the software development lifecycle, a challenging technical problem you resolved, how you keep code maintainable, and which tools you use for version control and collaboration. These reward concrete detail: a language and a project, a branching and review workflow you actually used, a test strategy you can describe. Three coding questions are also reported: reverse a string, explain depth-first versus breadth-first search, and give a simple dynamic programming example. Prepare to explain complexity and edge cases for each.

Two problem-solving questions ask how you would design a solution from a set of requirements and how you would troubleshoot a performance problem in a deployed application. Prepare each as a repeatable sequence you can narrate: for design, clarify requirements, list components and interfaces, decide how you would test each; for performance, reproduce, measure, find the bottleneck, change one thing and re-measure. Add the four behavioral prompts (leading an initiative, team conflict, motivation, and your lifecycle experience) and a project with ambiguous requirements, and you have the whole reported question set. Candidates also report that many positions may require on-site presence, so ask about that at the first conversation.

01

Initial Screening

reported

Candidates describe the Initial Screening as a first conversation about your background and fit for the role. No specific questions are tied to it in the reports. Treat it as the place where you set the frame for the later rounds: a short account of your career that points at design, coding and testing work, plus the practical questions you need answered about the process. Because candidates report a 3 to 5 week loop with three rounds, ask what the next stage involves and how it is scheduled.

What to demonstrate

  • How your background maps onto a software engineering role
  • How clearly you describe your own contribution to past work
  • Whether the practical details of the role (location, on-site expectations) work for you

How to prepare

  • Write a short career summary that names two projects where you designed, coded and tested something, and what you personally owned in each.
  • Choose one project where testing or verification mattered and be ready to say how you checked it worked.
  • Ask what the later rounds involve and whether the position requires on-site work, since candidates report that many defense-related positions do.
Ampersand Solutions Group Software Engineer candidate reports ↗
02

Technical Assessment

reported

Candidates report a Technical Assessment round. The reported question types that fit a technical stage are the knowledge questions (languages, lifecycle, code quality, tooling), the problem-solving questions (designing from requirements, troubleshooting performance) and the three coding questions (string reversal, depth-first versus breadth-first search, dynamic programming). Candidates also list object-oriented principles, the Model-View-Controller pattern, unit and integration testing and debugging among technical topics. Approach it by practising aloud: state the approach, write correct code in one language you know well, and give the complexity and edge cases without being asked.

What to demonstrate

  • Technical skills relevant to a software engineering position
  • Working code and sound reasoning on algorithm questions
  • Practical knowledge of testing and debugging
  • Ability to explain a technical decision clearly

How to prepare

  • Pick one of Java, C++ or Python and write string reversal, a BFS and a DFS, and one dynamic programming solution in it without references.
  • Rehearse the answers on languages, lifecycle, code quality and tooling with a named project behind each, so none is a list of buzzwords.
  • Walk through a design from a requirements list and a performance investigation from symptom to fix, each as a numbered sequence.
  • Write unit tests for your own solutions, including empty, single-element and large inputs, so you can speak about testing from practice.
Ampersand Solutions Group Software Engineer candidate reports ↗
03

Behavioral Interview

reported

Candidates describe the Behavioral Interview as a discussion focusing on your past experiences and interpersonal skills. Reported prompts include leading a project or initiative, handling conflict within a team, what motivates you, learning a technology quickly, persuading a teammate and keeping everyone on the same page. Candidates are advised to use the STAR structure (situation, task, action, result). Build a small set of stories that each cover several prompts, and write each in the first person so your own decisions are clear.

What to demonstrate

  • Your past experiences and what you personally did in them
  • Interpersonal skills: collaboration, conflict handling and communication with teammates and non-technical stakeholders

How to prepare

  • Write three stories (a project you led, a disagreement you resolved, a time you learned something fast) and note the decision you made and the result in each.
  • Prepare a one-minute answer on motivation that is tied to a specific example, not a general statement.
  • Prepare one story about an ambiguous requirement and how you got it clarified, since that prompt is also reported.
  • Prepare one story about explaining a technical point to a non-technical stakeholder or keeping a team on the same page, and practise saying I rather than we for each decision.
Ampersand Solutions Group Software Engineer candidate reports ↗

PracHub editorial advice for the preparation topics above.

01

Answering the languages question with a list (Java, C++, Python) and no evidence of depth

Name the language you code best in, one project you built with it, and a trade-off you understand (for example memory management in C++ versus the runtime in Java or Python). Give a second language only if you can discuss it too.

02

Reversing a string with a built-in call and never discussing edge cases or cost

Write the two-pointer swap yourself, state O(n) time, and say how it differs by language: C++ can reverse a character buffer in place, Java and Python strings are immutable so a copy is made. Test empty, single-character and non-ASCII input.

03

Defining depth-first and breadth-first search without data structures, complexity or a reason to choose one

State that BFS uses a queue and finds shortest paths in an unweighted graph, DFS uses a stack or recursion, both run in O(V+E), and a visited set is needed on graphs. Mention recursion depth as DFS's risk and queue width as BFS's.

04

Giving a slogan for code quality and testing (clean code, lots of tests) when verification and validation are among the reported topics

Describe practices you actually used: code review rules, unit and integration tests, tracing requirements to tests, and a defect you caught. Be able to explain verification versus validation.

05

Behavioral answers told as team stories with no individual decision, or conflict stories that blame a colleague

Write each story with a decision you made, the evidence you used and the result, in the first person. For conflict, show you understood the other view and followed the outcome.

Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.

12 technical prompts0 include a worked solution

Can you provide an example of how you approached a project with ambiguous requirements?

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Problem-Solving / Case Studies

Can you provide an example of how you approached a project with ambiguous requirements?

Approach
  1. List the unknowns explicitly and rank them by risk: which wrong guess would cost the most rework.
  2. Turn each unknown into a concrete question with options for the stakeholder ("should a failed record stop the batch or be skipped and logged?"), rather than an open-ended request.
  3. Write down the assumptions you proceed on and get them confirmed in writing, so a later change is a visible requirement change rather than a silent bug.
  4. Build the smallest working slice or prototype early to get feedback, and isolate the uncertain parts behind an interface so they can change without a rewrite.
  5. The story fails if you guessed silently and fixed it later; show the outcome and what the clarification saved.
Follow-up
  • What did you do when the stakeholder was not available to answer?
  • Tell me about an assumption that turned out wrong: how much did it cost?
  • How did you decide you had clarified enough to start building?

Write a function that reverses a string.

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Coding / Algorithms

Write a function that reverses a string.

Approach
  1. Clarify the input first: language, whether the string can be null or empty, and whether it contains non-ASCII characters.
  2. Python: s[::-1] or ''.join(reversed(s)), O(n) time and O(n) space because strings are immutable. Java: new StringBuilder(s).reverse().toString(), or toCharArray() plus two pointers. C++: std::reverse on a std::string reverses in place.
  3. Write the two-pointer version by hand: i at 0, j at n-1, swap and move inward while i < j; O(n) time, O(1) extra space on a mutable buffer.
  4. Cover edge cases: empty string, single character, palindromes, and Unicode. Reversing Java chars can split UTF-16 surrogate pairs (StringBuilder.reverse keeps them together), and reversing code points can still detach combining marks such as an accent.
Follow-up
  • Reverse the order of words in a sentence while keeping each word's letters in order.
  • Write it recursively: what is the space cost and what happens on a very long string?
  • How would you check whether a string is a palindrome ignoring case and punctuation?

Explain the difference between depth-first search and breadth-first search.

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Coding / Algorithms

Explain the difference between depth-first search and breadth-first search.

Approach
  1. BFS explores level by level using a FIFO queue; DFS goes as deep as possible before backtracking, using recursion or an explicit stack.
  2. Both run in O(V + E) time with an adjacency list (O(V^2) with an adjacency matrix); on graphs with cycles both need a visited set, and BFS should mark nodes when enqueuing to avoid duplicates.
  3. BFS finds the shortest path by edge count in an unweighted graph; for non-negative weights use Dijkstra instead. DFS suits topological sort, cycle detection, connected components and backtracking searches.
  4. Memory differs by shape: BFS holds a whole frontier, which can be very wide; DFS holds the current path, which can be very deep, so recursive DFS can overflow the stack (Python's default recursion limit is 1000).
Follow-up
  • Find the shortest path from one cell to another in a grid with obstacles.
  • How do you detect a cycle in a directed graph with DFS?
  • Rewrite your recursive DFS iteratively: what changes in visit order?

Can you solve a problem using dynamic programming? Provide a simple example.

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Coding / Algorithms

Can you solve a problem using dynamic programming? Provide a simple example.

Approach
  1. Name the two conditions for DP: overlapping subproblems and optimal substructure, then pick an example such as minimum coins for an amount.
  2. Define the state and recurrence: dp[0] = 0, dp[a] = min over coins c <= a of dp[a - c] + 1, unreachable amounts stay infinity and return -1; O(n * amount) time, O(amount) space.
  3. Show why greedy fails: coins {1, 3, 4} and amount 6, greedy takes 4+1+1 (three coins) while the optimum is 3+3 (two coins).
  4. Contrast top-down memoization (recursion plus cache, computes only reachable states, risks deep recursion) with bottom-up tabulation (iterative, easy to reduce space, e.g. Fibonacci in O(1) space with two variables).
  5. Edge cases: amount 0 returns 0, no coin fits, duplicate coin values.
Follow-up
  • Count the number of ways to make the amount instead: why does putting the coin loop outside give combinations rather than permutations?
  • How would you reconstruct which coins were used, not just the count?
  • How does 0/1 knapsack differ from this unbounded version in the loop order?

The plan follows the three reported rounds: Day 1 covers the screening conversation and tooling answers, Days 2 to 4 cover the coding, design and troubleshooting questions, Day 5 covers verification, lifecycle, testing and security, and Days 6 and 7 cover the behavioral prompts and a full rehearsal.

Small steps. Visible outcomes.0 / 7 completed
ONE WEEK · YOUR PACE

Prepare, practise & reflect

One practical outcome each day. Spend longer where you need it.

0 / 7 done
01Screening story, languages and tooling
  • Write a short career summary that points at design, coding and testing work and names the two projects you will use throughout.
  • Write your answer on languages: the one you code best in, one project, and a trade-off you understand in it.
  • Write your answer on version control and collaboration tools: branching, code review and how you shared work with QA and operations colleagues.

Deliverable: A written career summary, a language answer and a tooling answer, each tied to a named project.

Practice prompt ↗Practice prompt ↗
02String reversal and graph search
  • Write string reversal in your main language using two pointers, state its complexity, and test empty, single-character and non-ASCII input.
  • Implement BFS and DFS on a graph (iterative and recursive DFS) with a visited set, and note O(V+E) time.
  • Write a short spoken explanation of when you would choose BFS over DFS, covering shortest paths and memory use.

Deliverable: Working string reversal, BFS and DFS code with tests, and a spoken comparison of the two searches.

Practice prompt ↗Practice prompt ↗
03Dynamic programming and a second language
  • Solve a simple dynamic programming problem such as climbing stairs or coin change: write the recursion, add memoization, then the bottom-up version.
  • State the time and space complexity of each version and reduce space where possible.
  • Redo string reversal or BFS in a second language from Java, C++ or Python so you can discuss it.

Deliverable: Two versions of one dynamic programming solution with complexities, and one algorithm rewritten in a second language.

Practice prompt ↗Practice prompt ↗Practice prompt ↗
04Design from requirements and performance troubleshooting
  • Take a short requirements list (your own or an invented one) and write a design: components, interfaces, data, failure cases and how you would test each part.
  • Write a numbered troubleshooting sequence for a slow deployed application: reproduce, measure latency and resource use, profile, form one hypothesis, change one thing, re-measure.
  • Practise explaining the Model-View-Controller pattern and object-oriented principles in a minute each, with an example from your own code.
  • Since radar systems are among the reported projects, outline one project story about a time, memory or data-volume constraint (a latency target, a fixed memory budget, a large input) and how you met it.

Deliverable: One written design with a test approach, one numbered performance-troubleshooting sequence, and one constraint-driven project story.

Practice prompt ↗Practice prompt ↗
05Verification, validation, lifecycle, code quality and security
  • Write the definitions of verification and validation in your own words with one example each from your work, plus a sentence on what Independent adds: checking by a group separate from the developers, such as reviewing requirements and test artifacts and re-running tests.
  • Write your lifecycle answer around one project, naming what each phase produced and where you owned the work.
  • Write your code quality answer: review rules, unit and integration tests, one defect your practices caught, and the security practices you have used (input validation, least privilege, dependency or static-analysis scanning).
  • Choose the challenging technical problem you will describe and outline it as problem, diagnosis, fix and result.

Deliverable: A verification and validation definition with examples, a lifecycle answer, a code quality answer with security practices, and an outlined technical-problem story.

Practice prompt ↗Practice prompt ↗Practice prompt ↗
06Ambiguity, leadership, conflict and stakeholder stories
  • Write the ambiguous-requirements story: what was unclear, who you asked, what you assumed and how you confirmed it.
  • Write the leadership story in STAR form with two challenges, each with the action you took, and the conflict story with both viewpoints, the evidence you used and the outcome.
  • Write a stakeholder story: how you explained a technical point to a non-technical person, or how you made sure everyone was on the same page during a project.
  • Say each story aloud and replace every we with I where you made the decision.

Deliverable: Four written stories (ambiguity, leadership, conflict, stakeholder communication) rehearsed aloud.

Practice prompt ↗Practice prompt ↗Practice prompt ↗
07Full rehearsal across all three rounds
  • Give your career summary and then your motivation answer, backed by an example, as if in the screening.
  • Answer the languages, lifecycle and troubleshooting questions aloud, then write string reversal and BFS from memory without references.
  • Tell the leadership and conflict stories back to back and note where they run long or lose the decision you made.

Deliverable: One recorded full rehearsal and a short list of the weakest answers to fix before the loop.

Practice prompt ↗Practice prompt ↗Practice prompt ↗Practice prompt ↗Practice prompt ↗Practice prompt ↗Practice prompt ↗Practice prompt ↗

Expand any day for tasks and deliverables. Your progress is saved on this device.

Candidates describe the Behavioral Interview as a discussion focusing on your past experiences and interpersonal skills. Reports for this role mention working with product management, quality assurance and operations colleagues, communicating technical ideas to non-technical stakeholders, and resolving disagreements. Choose stories from projects that involved testing or verification where you can, and rehearse them in STAR form with your own decisions in the first person.

Can you explain the software development lifecycle and your experience with it?

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Technical / Domain Questions

Can you explain the software development lifecycle and your experience with it?

Approach
  1. Give the lifecycle in your own sequence: requirements, design, implementation, testing, release and maintenance. Then say which model you actually worked in (gated phases, Agile iterations or a mix) and where the phases blurred in practice.
  2. Anchor it to one project and name what each phase produced: a requirements list, a design review, merged code, test results, a release checklist. Say clearly which phases you owned.
  3. Spend extra time on testing and verification: unit, integration and system tests, and how a requirement was traced to the tests that covered it. State the difference between verification (the build matches the specification) and validation (it meets the real need), since V&V is among the reported topics.
  4. Include one case where the process let you down, such as a requirement that surfaced late or a defect found after release, and what you changed afterwards.
  5. A textbook list of phases with no project behind it is the usual weak answer; keep the definition short and the experience long.
Follow-up
  • Where do code review and test planning sit in that lifecycle?
  • What did you change when a requirement arrived late?
  • How did you trace a requirement to the tests that covered it?

Describe a time when you had to lead a project or initiative. What challenges did you face?

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Behavioral / Leadership

Describe a time when you had to lead a project or initiative. What challenges did you face?

Approach
  1. Choose a project where you set direction or coordinated others, even without a title. Open with scope in one or two sentences: team size, goal and the constraint that made it hard.
  2. Name two or three concrete challenges (unclear scope, a slipping dependency, a blocked teammate) and the action you took for each. Use I for your own decisions and keep the team's work separate.
  3. Show how you led: how you split the work and assigned owners, how you checked progress, how you handled review and integration, and how you tracked risk.
  4. Close with the result and one thing you would change. Quantify only what you can defend, such as the delivery date met, defects found before release or hours saved.
  5. The common failure is a story where the team succeeds and your part is unclear, or where leading meant working extra hours; show decisions, not effort.
Follow-up
  • How did you decide who took which piece of work?
  • What did you do when someone fell behind?
  • What would you do differently if you led it again?

How do you handle conflicts within a team?

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Behavioral / Leadership

How do you handle conflicts within a team?

Approach
  1. Pick a real technical disagreement, such as a design approach, review comments or who owns a bug, rather than a pure personality clash. State what each side wanted and why both positions had merit.
  2. Describe the steps in order: you spoke to the person directly first, listened to their reasoning, agreed on the shared goal, then used evidence (a benchmark, a prototype, a failing test, the specification) to decide. Escalate only if that fails.
  3. Say what was decided, who decided it and that you carried it out fully even if it went against your preference.
  4. End with the working relationship afterwards and a practice you changed, for example a short design note before implementation or clearer review conventions.
  5. Do not cast the other person as the villain, and do not claim you never have conflicts; both read as lack of experience.
Follow-up
  • What if the person still disagreed after you showed the evidence?
  • When would you bring in a manager?
  • Tell me about a time you were the one who was wrong.

What motivates you to perform well in your role?

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Behavioral / Leadership

What motivates you to perform well in your role?

Approach
  1. This is not a STAR question. Name one or two drivers and back each with an example of what you did when driven by it, such as staying with a failing test until you found the root cause or shipping work others depended on.
  2. Link it honestly to the work this role is reported to involve: software designed, coded and tested against specifications, across areas from radar systems to full-stack development. Say what in that appeals to you only if it is true.
  3. Add what you do when motivation dips (a smaller next step, a conversation with a teammate, a change of task) so the answer shows self-management and not only enthusiasm.
  4. Keep it short. Generic lines about challenge and growth, or repeating mission statements you have not thought about, are the common weak answers.
Follow-up
  • Tell me about a time your motivation was tested and what you did.
  • What kind of work drains you, and how do you handle it?
  • How do you stay careful on routine, detail-heavy work such as retesting?
  • 01

    Describe a time when you had to lead a project or initiative. What challenges did you face?

  • 02

    How do you handle conflicts within a team?

  • 03

    What motivates you to perform well in your role?

  • 04

    How do you ensure that everyone is on the same page during a project?

  • 05

    Can you discuss a time you had to persuade a team member to adopt your approach?

  • 06

    Can you explain the software development lifecycle and your experience with it?

PracHub preparation framework ↗
How many rounds are there and how long does the loop take?

Candidates report three rounds: Initial Screening, Technical Assessment and Behavioral Interview, over roughly 3 to 5 weeks. Scheduling varies, so ask the recruiter what comes next after each stage.

Ampersand Solutions Group Software Engineer candidate reports ↗
What topics should I prepare beyond coding?

The reported topics are Software Engineering, Verification & Validation (V&V), Independent Verification (IV), Independent Validation (IVa) and Radar Software Engineering. Prepare to explain verification versus validation, how you test your own code and how you trace requirements to tests.

Ampersand Solutions Group Software Engineer candidate reports ↗
Which programming language should I use?

Java, C++ and Python are the languages listed as examples for this role, depending on the team. For live problems, use the one you code best in and rehearse string reversal, BFS, DFS and a dynamic programming example in it. Be ready to discuss a second language if you claim it.

PracHub Software Engineer practice ↗
Will the job require working on site?

Candidates report that many positions may require on-site presence, particularly defense-related ones, and that flexibility varies. Ask about the location and on-site expectations for your specific position in the first conversation.

Ampersand Solutions Group Software Engineer candidate reports ↗
Is there a separate system design round?

None is reported among the three rounds. A design question is reported, though: how you would approach designing a software solution from a set of requirements. Prepare it as a sequence of clarifying requirements, choosing components and interfaces, handling failures and planning tests.

PracHub Software Engineer practice ↗
What background do candidates describe for this role?

Reports describe a degree in computer science or a related field and roughly 2 to 5 years of software development experience. Familiarity with cloud platforms and DevOps practices, Agile methods and cybersecurity principles is listed as a plus. Have a project ready for any of these you have experience with.

PracHub Software Engineer practice ↗
Sources & methodology 3 sources ↗

No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.