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Lockheed Martin Software Engineer Interview Guide

Lockheed Martin Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

As a Software Engineer at Lockheed Martin, you play a vital role in developing mission-critical systems that defend security, advance space exploration, and push the boundaries of aerospace engineering. Software is at the core of Lockheed Martin's advanced platforms, driving everything from tactical flight control systems and radar signal processing to autonomous sensor fusion, satellite communication networks, and simulation frameworks. In this position, your work directly impacts the reliability, safety, and performance of complex hardware-software integration projects. Whether you are building real-time embedded C++ firmware for aerospace platforms, engineering enterprise cloud pipelines in Java or Python, or supporting digital twin simulations, your code directly supports service members and mission partners globally.

This guide is scoped to a Software Engineer candidate at Lockheed Martin.

Focus areas

  • STAR interview method (Situation, Task, Action, Result)
  • Behavioral interview questions
  • Resume screening / resume review

The Lockheed Martin interview process

Lockheed Martin candidates report 4 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Online Application

Candidates begin their journey by submitting an online application or engaging in campus recruitment.

What to demonstrate

  • Candidates begin their journey by submitting an online application or engaging in campus recruitment
  • Depth in STAR interview method (Situation, Task, Action, Result)

How to prepare

  • Answer aloud and timed: Describe a time when you faced a significant technical challenge during a team project. How did you approach and resolve it?
  • Answer aloud and timed: Tell me about a time you had a disagreement with a team member or project lead regarding a technical implementation. How was it resolved?

Resume Screening

Initial screening of resumes to assess basic qualifications and fit for the role.

What to demonstrate

  • Initial screening of resumes to assess basic qualifications and fit for the role
  • Depth in STAR interview method (Situation, Task, Action, Result)

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.

Introductory Screening

A brief phone or virtual screening focused on qualifications, interest, and security clearance.

What to demonstrate

  • A brief phone or virtual screening focused on qualifications, interest, and security clearance
  • Depth in STAR interview method (Situation, Task, Action, Result)

How to prepare

  • Answer aloud and timed: Describe a situation where you made a mistake on a software task or project. What steps did you take to correct it and prevent future occurrences?
  • Answer aloud and timed: What are the four main pillars of Object-Oriented Programming, and how have you applied them in your past projects?

Virtual Panel Interview

A 45 to 60-minute virtual panel interview with the hiring manager and senior engineers.

What to demonstrate

  • A 45 to 60-minute virtual panel interview with the hiring manager and senior engineers
  • Depth in STAR interview method (Situation, Task, Action, Result)

How to prepare

  • Answer aloud and timed: Explain the concept of inheritance versus composition. When would you choose one over the other?
  • Answer aloud and timed: What is abstraction, and how do you achieve it in C++ or Java?

Where candidates lose points

Prepare specific STAR stories in advance

Create a preparation matrix with 5–7 detailed stories covering topics like handling project delays, resolving technical conflicts, overcoming bugs, and learning new tech stacks quickly.

Know every line on your resume

Be prepared to explain any project, programming language, or tool listed on your resume in depth. Interviewers frequently choose specific resume points and ask detailed questions about your personal contribution.

Research the specific Lockheed Martin business area

Understand what the group you are interviewing with produces—whether it is flight control systems at Aeronautics, radar technologies at RMS, space systems, or missile defense platforms at MFC.

Questions & practice

Explain the difference between compiled languages (like C++) and interpreted languages (like Python). How does

Medium · Object-Oriented Programming (OOP) & Fund

Explain the difference between compiled languages (like C++) and interpreted languages (like Python). How does memory management differ?

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Walk me through how you would structure a program to find prime numbers, search a list, or reverse a string ef

Medium · Software Design, Systems & Coding Logic

Walk me through how you would structure a program to find prime numbers, search a list, or reverse a string efficiently.

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. 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?

Describe your experience with data structures such as linked lists, arrays, hash maps, and binary trees.

Medium · Software Design, Systems & Coding Logic

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. 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?

Explain basic operating system concepts such as process vs. thread, synchronization, and memory management.

Medium · Software Design, Systems & Coding Logic

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Keep soft-deleted accounts from blocking re-registration

Easy · soft delete · unique constraints · engine differences

app_user holds user_id, tenant_id, email CITEXT, password_hash (NULL for SSO principals), email_verified_at, auth_version, status ('invited','active','suspended','deactivated'), created_at, updated_at, deleted_at. Two live accounts for one address inside a tenant must be impossible, but an address freed by a soft delete must be reusable, and the same tenant may delete and re-register it repeatedly. Write the uniqueness DDL for PostgreSQL 16, then the equivalent for MySQL 8 where partial indexes do not exist, and say what each permits once three deleted rows already hold that address.

Approach

  1. Start from what is actually unique: not (tenant_id, email), but (tenant_id, email) among live rows. PostgreSQL says that directly — CREATE UNIQUE INDEX app_user_live_email ON app_user (tenant_id, email) WHERE deleted_at IS NULL. A full constraint over the same two columns burns the address permanently the first time someone deletes an account.
  2. Keep case-insensitivity in the type or the index, never in the application: CITEXT as given, or UNIQUE (tenant_id, lower(email)) as an expression index where the extension is unavailable. A case-sensitive unique column is exactly how two accounts for one human appear.
  3. For MySQL 8 the predicate has to move inside the key: add a discriminator column that is a constant 0 while the row is live and is set to user_id on delete, with UNIQUE (tenant_id, email, deleted_marker). Live rows share the constant and still collide; deleted rows differ from each other and stop colliding.
  4. State the NULL variant and its dependency: leaving the marker NULL for deleted rows also works, because a unique index treats NULLs as distinct — true in MySQL, and true in PostgreSQL only under the default NULLS DISTINCT, which PostgreSQL 15 lets you reverse. Check the polarity against the three existing deleted rows: constant-on-live is what preserves the collision you want, and reversing it silently admits duplicate live accounts.

Follow-up

  • A deleted account re-registers with the same address the next day. Do the old resource rows follow the new user_id, and how does the API keep the two principals apart?
  • How do you honour an erasure request while resource_revision.actor_user_id still references this table?

Find version gaps and relay lag with window functions

Medium · window functions · event tables · frame semantics

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

  1. 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.
  2. 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.
  3. 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.
  4. 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?

What are the four main pillars of Object-Oriented Programming, and how have you applied them in your past proj

Medium · Object-Oriented Programming (OOP) & Fund

What are the four main pillars of Object-Oriented Programming, and how have you applied them in your past projects?

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Explain the concept of inheritance versus composition. When would you choose one over the other?

Medium · Object-Oriented Programming (OOP) & Fund

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

What is abstraction, and how do you achieve it in C++ or Java?

Medium · Object-Oriented Programming (OOP) & Fund

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

What is the difference between a stack and a queue? Describe a real-world scenario where you would choose a st

Medium · Object-Oriented Programming (OOP) & Fund

What is the difference between a stack and a queue? Describe a real-world scenario where you would choose a stack over a queue.

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 integrate unit testing and continuous delivery practices into your software development workflow?

Medium · Software Design, Systems & Coding Logic

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

How do you approach debugging a complex multi-threaded application or an issue that only occurs intermittently

Medium · Software Design, Systems & Coding Logic

How do you approach debugging a complex multi-threaded application or an issue that only occurs intermittently in software?

Approach

  1. Establish what changed and when, before forming any theory.
  2. Pick a bisection that eliminates candidates whichever way it turns out.
  3. Check the instrumentation before believing the symptom.
  4. 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?

Suggested practice checklist

Built from the rounds and topics Lockheed Martin candidates report.

Day 1 — Map the Lockheed Martin loop

  • Write out the reported sequence: Online Application, Resume Screening, Introductory Screening, Virtual Panel Interview.
  • 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 4 reported rounds, with the weakest marked.

Day 2 — Work STAR interview method (Situation, Task, Action, Result)

  • Spend the session on STAR interview method (Situation, Task, Action, Result), which Lockheed Martin candidates report being tested on.
  • Write one worked example in STAR interview method (Situation, Task, Action, Result) and time yourself on it.

Deliverable: One timed worked example in STAR interview method (Situation, Task, Action, Result).

Day 3 — Work Behavioral interview questions

  • Spend the session on Behavioral interview questions, which Lockheed Martin candidates report being tested on.
  • Write one worked example in Behavioral interview questions and time yourself on it.

Deliverable: One timed worked example in Behavioral interview questions.

Day 4 — Work Resume screening / resume review

  • Spend the session on Resume screening / resume review, which Lockheed Martin candidates report being tested on.
  • Write one worked example in Resume screening / resume review and time yourself on it.

Deliverable: One timed worked example in Resume screening / resume review.

Day 5 — Answer out loud: Behavioral & Leadership Scenarios

  • Answer aloud, timed: Describe a time when you faced a significant technical challenge during a team project. How did you approach and resolve it?
  • Answer aloud, timed: Tell me about a time you had a disagreement with a team member or project lead regarding a technical implementation. How was it resolved?

Deliverable: Spoken answers to 2 reported Behavioral & Leadership Scenarios question(s), under time.

Day 6 — Answer out loud: Object-Oriented Programming (OOP) & Fundamentals

  • Answer aloud, timed: What are the four main pillars of Object-Oriented Programming, and how have you applied them in your past projects?
  • Answer aloud, timed: Explain the concept of inheritance versus composition. When would you choose one over the other?

Deliverable: Spoken answers to 2 reported Object-Oriented Programming (OOP) & Fundamentals question(s), under time.

Day 7 — Answer out loud: Software Design, Systems & Coding Logic

  • Answer aloud, timed: Walk me through how you would structure a program to find prime numbers, search a list, or reverse a string efficiently.
  • Answer aloud, timed: Describe your experience with data structures such as linked lists, arrays, hash maps, and binary trees.

Deliverable: Spoken answers to 2 reported Software Design, Systems & Coding Logic question(s), under time.

Behavioural preparation

Behavioural rounds judge the decision you made and what it cost.

Describe a time when you faced a significant technical challenge during a team project. How did you approach a

Medium · Behavioral & Leadership Scenarios

Describe a time when you faced a significant technical challenge during a team project. How did you approach and resolve it?

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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?

Tell me about a time you had a disagreement with a team member or project lead regarding a technical implement

Medium · Behavioral & Leadership Scenarios

Tell me about a time you had a disagreement with a team member or project lead regarding a technical implementation. How was it resolved?

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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?

Give an example of a project where you had to quickly learn a new programming language, tool, or domain framew

Medium · Behavioral & Leadership Scenarios

Give an example of a project where you had to quickly learn a new programming language, tool, or domain framework to meet a tight deadline.

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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 organize and prioritize your workload, communications, and daily tasks when managing multiple compe

Medium · Behavioral & Leadership Scenarios

How do you organize and prioritize your workload, communications, and daily tasks when managing multiple competing priorities?

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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 made a mistake on a software task or project. What steps did you take to correc

Medium · Behavioral & Leadership Scenarios

Describe a situation where you made a mistake on a software task or project. What steps did you take to correct it and prevent future occurrences?

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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?