A Software Engineer at LinQuest plays a vital role in developing innovative solutions that support critical missions in the defense and space sectors. This position is essential to the design, implementation, and maintenance of software systems that power advanced technologies used in various projects, including satellite operations and defense systems. As a Software Engineer, you will contribute to projects that not only require technical expertise but also a deep understanding of complex systems and their applications in real-world scenarios. The impact of this role extends beyond just coding; it involves collaboration with cross-functional teams to ensure that the software aligns with mission objectives and user needs. You will be tasked with solving challenging problems that influence the trajectory of national security and space exploration, making your contributions both significant and rewarding. Expect to engage with cutting-edge technologies and be part of a team that prioritizes innovation and excellence.
Phone Screen
reportedInitial screening call to assess candidate's background and role fit.
What to demonstrate
- Initial screening call to assess candidate's background and role fit
- Depth in Space Mission Analysis and Design
How to prepare
- Be able to walk your CV end to end in two minutes, and say why this company specifically.
- Have your salary expectations, notice period and location constraints ready, and ask for the rest of the loop in writing.
Technical Interviews
reportedOne or more interviews that may include coding exercises and system design discussions.
What to demonstrate
- One or more interviews that may include coding exercises and system design discussions
- Depth in Space Mission Analysis and Design
How to prepare
- Answer aloud and timed: How do you approach debugging a complex software issue?
- Answer aloud and timed: Can you describe a time when you faced a significant challenge at work and how you handled it?
Behavioral Assessment
reportedEvaluation of past experiences and collaborative problem-solving abilities.
What to demonstrate
- Evaluation of past experiences and collaborative problem-solving abilities
- Depth in Space Mission Analysis and Design
How to prepare
- Prepare three examples from your own work, each with a decision you made and an outcome you can quantify.
- Re-read the description of the behavioral assessment above and write down what you would ask to confirm before it.
PracHub editorial advice for the preparation topics above.
Prepare for technical assessments
Brush up on your coding skills and be ready to solve problems live during interviews.
Understand the mission
Familiarizing yourself with LinQuest's projects and objectives can help you align your answers with the company’s goals.
Practice behavioral questions
Reflect on your past experiences and be ready to discuss how they relate to the role you’re applying for.
Be open about your career goals
Understanding how your ambitions align with LinQuest can help you position yourself as a strong cultural fit.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Write a function to reverse a linked list.
Write a function to reverse a linked list.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
How would you implement a binary search algorithm in your preferred programming language?
How would you implement a binary search algorithm in your preferred programming language?
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Discuss the time and space complexity of your algorithm.
Discuss the time and space complexity of your algorithm.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Find version gaps and relay lag with window functions
outbox_event holds event_id, aggregate_type, aggregate_id, aggregate_version, event_type, payload, status ('pending','published','dead'), attempts, created_at, published_at. A projection is missing rows and you must decide whether the relay skipped events or the consumer dropped them. Write three queries over the last seven days: one listing every aggregate_id whose published aggregate_version sequence has a hole, one giving per-day counts with a running total, and one returning the newest published event per aggregate. For each, say where the window function is evaluated relative to WHERE and LIMIT. PostgreSQL 16.
Approach
- Gaps: compute lead(aggregate_version) OVER (PARTITION BY aggregate_id ORDER BY aggregate_version) in a subquery, then filter next_version <> aggregate_version + 1 in the outer query. Window functions are evaluated after WHERE, GROUP BY and HAVING and before the outer ORDER BY and LIMIT, so the predicate cannot sit in the same WHERE clause and PostgreSQL 16 has no QUALIFY.
- Say what the seven-day filter does to the answer: it truncates every partition, so the first row per aggregate has no predecessor inside the window and a hole spanning the boundary is invisible. Widen the window, or join to resource.version as the authority for the true maximum.
- Running total: SELECT date_trunc('day', created_at) AS d, count() AS n, sum(count()) OVER (ORDER BY date_trunc('day', created_at) ROWS UNBOUNDED PRECEDING). An aggregate inside a window call is legal because grouping runs before windowing. The grouping key is unique per row here so ROWS and RANGE agree, but write the frame anyway — over ungrouped rows with tied timestamps the default RANGE frame pulls in every peer row and the total jumps.
- Newest per aggregate: DISTINCT ON (aggregate_id) ... ORDER BY aggregate_id, aggregate_version DESC is the cheap PostgreSQL-only form when an index matches that order; row_number() OVER (PARTITION BY aggregate_id ORDER BY aggregate_version DESC) = 1 is the portable form and needs a subquery for the same evaluation-order reason as the gap query.
Follow-up
- Relay failover redelivers events. Does a duplicate break the gap query, and how would you detect one from this table alone?
- Turn the gap check into a continuous monitor rather than a query someone runs after an incident. What does it watch?
Stop tag and share joins from fanning out a page
resource_tag is (resource_id, tag_id) with PK (resource_id, tag_id); resource_share is (resource_id, shared_with_user_id, permission). The tagged-and-shared listing inner-joins resource to both, filters tenant_id, tag_id = ANY($2) and shared_with_user_id = $3, orders by updated_at DESC and takes 50. Pages come back with fewer than 50 distinct resources and the total in the header is far too high. Explain the row multiplication, rewrite both the page query and the count query so each is correct, and name the index each one needs. PostgreSQL 16.
Approach
- Do the arithmetic against the predicates that are actually there. An inner join emits one row per matching child row, and both joins are filtered: tag_id = ANY($2) admits only the requested tags, shared_with_user_id = $3 admits one user's share rows. So a resource holding three of the requested tags and shared with $3 once yields three rows, not one — the multiplier is its count of matching tags times its share rows for that single user, and that second factor is 1 unless the table admits duplicate (resource_id, shared_with_user_id) pairs. LIMIT 50 then limits rows rather than resources, and COUNT(*) counts pairs — the header is the product, not the population.
- Reject DISTINCT as the fix. It deduplicates after the product has been built, so the planner must materialise and sort the fanned-out set before the LIMIT can apply, and it leaves any SUM or AVG in the same select list wrong.
- Rewrite both filters as semi-joins, keeping resource as the only row source: AND EXISTS (SELECT 1 FROM resource_tag rt WHERE rt.resource_id = r.resource_id AND rt.tag_id = ANY($2)) and the same shape against resource_share. A semi-join stops at the first match per resource and preserves the driving index order, so ORDER BY updated_at DESC, resource_id DESC LIMIT 50 still stops after 50 rows.
- Count with the same predicates and no join at all: SELECT count(*) FROM resource r WHERE r.tenant_id = $1 AND r.status = 'active' AND EXISTS (...) AND EXISTS (...). Nothing multiplies a resource, so the number is the population.
Follow-up
- The filter changes from 'any of these tags' to 'all of these tags'. Rewrite it and state what it costs relative to the ANY form.
- A resource can be shared with the same user twice under different permissions. Does your count change, and should it?
What programming languages are you most comfortable with, and why?
What programming languages are you most comfortable with, and why?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
Describe a software project you worked on and the technologies you used.
Describe a software project you worked on and the technologies you used.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
How would you design a system for real-time data processing?
How would you design a system for real-time data processing?
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
What factors do you consider when designing scalable software systems?
What factors do you consider when designing scalable software systems?
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
Describe the trade-offs between different database technologies you've used.
Describe the trade-offs between different database technologies you've used.
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
Walk me through your thought process for resolving a complex technical problem.
Walk me through your thought process for resolving a complex technical problem.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
If you were given a new programming language you were unfamiliar with, how would you approach learning it?
If you were given a new programming language you were unfamiliar with, how would you approach learning it?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
How do you approach debugging a complex software issue?
How do you approach debugging a complex software issue?
Approach
- Establish what changed and when, before forming any theory.
- Pick a bisection that eliminates candidates whichever way it turns out.
- Check the instrumentation before believing the symptom.
- Separate the trigger from the cause; the deploy is rarely the bug.
Follow-up
- What would you look at first, and what would it rule out?
- How would you tell a cause from a coincidence here?
Built from the rounds and topics LinQuest candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the LinQuest loop
- Write out the reported sequence: Phone Screen, Technical Interviews, Behavioral Assessment.
- For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.
Deliverable: A one-page map of the 3 reported rounds, with the weakest marked.
02Work Space Mission Analysis and Design
- Spend the session on Space Mission Analysis and Design, which LinQuest candidates report being tested on.
- Write one worked example in Space Mission Analysis and Design and time yourself on it.
Deliverable: One timed worked example in Space Mission Analysis and Design.
03Work Systems Engineering
- Spend the session on Systems Engineering, which LinQuest candidates report being tested on.
- Write one worked example in Systems Engineering and time yourself on it.
Deliverable: One timed worked example in Systems Engineering.
04Work Critical Thinking
- Spend the session on Critical Thinking, which LinQuest candidates report being tested on.
- Write one worked example in Critical Thinking and time yourself on it.
Deliverable: One timed worked example in Critical Thinking.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: What programming languages are you most comfortable with, and why?
- Answer aloud, timed: Describe a software project you worked on and the technologies you used.
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Can you describe a time when you faced a significant challenge at work and how you handled it?
- Answer aloud, timed: How do you prioritize tasks when working on multiple projects?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
07Answer out loud: System Design / Architecture
- Answer aloud, timed: How would you design a system for real-time data processing?
- Answer aloud, timed: What factors do you consider when designing scalable software systems?
Deliverable: Spoken answers to 2 reported System Design / Architecture question(s), under time.
Expand any day for tasks and deliverables. Your progress is saved on this device.
Behavioural rounds judge the decision you made and what it cost.
Can you describe a time when you faced a significant challenge at work and how you handled it?
Can you describe a time when you faced a significant challenge at work and how you handled it?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
How do you prioritize tasks when working on multiple projects?
How do you prioritize tasks when working on multiple projects?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
Describe a situation where you had to work with a difficult team member. How did you manage the relationship?
Describe a situation where you had to work with a difficult team member. How did you manage the relationship?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
- 01
Can you describe a time when you faced a significant challenge at work and how you handled it?
- 02
How do you prioritize tasks when working on multiple projects?
- 03
Describe a situation where you had to work with a difficult team member. How did you manage the relationship?
How difficult are the interviews at LinQuest?
Interviews can be challenging, particularly in the technical and problem-solving areas. Candidates typically spend a few weeks preparing to ensure they are ready to demonstrate their skills and knowledge effectively.
LinQuest Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often have a strong technical foundation, excellent problem-solving skills, and the ability to communicate effectively. They also align well with the company’s values and culture.
LinQuest Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
Candidates can expect the process to take a few weeks, depending on the number of interview rounds and the scheduling availability of the interviewers.
LinQuest Software Engineer candidate reports ↗Is there an emphasis on remote work or hybrid expectations?
LinQuest generally supports flexible work arrangements, but specific policies may vary by team and project requirements.
LinQuest Software Engineer candidate reports ↗What topics does LinQuest test in interviews?
LinQuest interviews most often cover Space Mission Analysis and Design, Excel (Advanced/Practical Use), Financial Analysis, Systems Engineering, and Analytical Problem Solving. The exact emphasis depends on the specific role you apply for.
LinQuest Software Engineer candidate reports ↗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.
- 01LinQuest Software Engineer candidate reports ↗
Company-reported rounds, questions and FAQ.
Candidate reports · Accessed 2026-09-22 - 02PracHub Software Engineer practice ↗
PracHub practice material, not company-reported.
PracHub page · Accessed 2026-09-22 - 03PracHub preparation framework ↗
PracHub preparation guidance.
PracHub page · Accessed 2026-09-22
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