A Software Engineer at SRC plays a pivotal role in developing sophisticated technical solutions that support critical national defense and intelligence missions. You will not just be writing code; you will be solving complex problems in domains like radar systems, electronic warfare, and data analysis. This position is central to the company’s ability to deliver high-stakes, reliable technology that functions in challenging real-world environments. Working at SRC means you are often contributing to projects that require a high degree of precision and innovative thinking. Whether you are working on modeling and simulation, C++ systems, or Model-Based Systems Engineering (MBSE), you are expected to bring a strong analytical mindset to the table. The role offers the opportunity to work alongside highly intelligent, mission-focused teams, making it an ideal environment for engineers who value technical depth and tangible, impactful outcomes. ##### Tip SRC places significant value on candidates who can communicate technical concepts clearly. Be prepared to explain your thought process as much as the final result.
Recruiter Phone Screen
reportedInitial screening call with a recruiter or hiring manager to evaluate your fit for the role.
What to demonstrate
- Initial screening call with a recruiter or hiring manager to evaluate your fit for the role
- Depth in Behavioral Interviewing
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 Discussions
reportedIn-depth technical discussions to assess your technical competence and problem-solving skills.
What to demonstrate
- In-depth technical discussions to assess your technical competence and problem-solving skills
- Depth in Behavioral Interviewing
How to prepare
- Answer aloud and timed: Describe the differences between interfaces and classes in Java.
- Answer aloud and timed: Can you explain key concepts in electromagnetism?
Panel or On-site Experience
reportedComprehensive panel interview or on-site experience to evaluate both technical and behavioral aspects.
What to demonstrate
- Comprehensive panel interview or on-site experience to evaluate both technical and behavioral aspects
- Depth in Behavioral Interviewing
How to prepare
- Answer aloud and timed: How would you approach designing an object-oriented solution for a system like an elevator or a board game?
- Answer aloud and timed: Tell me about yourself and your interest in SRC.
PracHub editorial advice for the preparation topics above.
Understand the "Why
Don't just show the solution; explain why you chose that approach over alternatives.
Be ready for multiple rounds of introductions
You may meet with several different people throughout the day; keep your "tell me about yourself" story consistent but tailored to the specific interviewer's role.
Ask meaningful questions
Use your time at the end of the interview to ask about the team’s current challenges, the company’s culture, or the impact of the project you would be working on.
Review your resume thoroughly
Be prepared to discuss every project and technology you have listed in detail.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
What is a hash map, and when would you choose to use one?
What is a hash map, and when would you choose to use one?
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?
Walk me through a simple algorithmic problem (LeetCode Easy level).
Walk me through a simple algorithmic problem (LeetCode Easy level).
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?
Can you explain a complex technical topic to someone without a technical background?
Can you explain a complex technical topic to someone without a technical background?
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?
Explain why the owner filter ignores the listing index
The only index on resource is (tenant_id, status, updated_at DESC, resource_id DESC). A new endpoint returns one user's resources across all statuses, newest created first: WHERE tenant_id = $1 AND owner_user_id = $2 ORDER BY created_at DESC LIMIT 20. On a tenant with 2M rows it takes 900 ms and EXPLAIN shows a sort above a large scan. Explain precisely why the existing index cannot serve it, give the index that can, and state which of these the new index still will not help: owner_user_id alone across tenants; the same query ordered by updated_at. PostgreSQL 16.
Approach
- Separate the two jobs an index does. For filtering, a composite btree is seekable only on a left prefix, so with no predicate on status the scan can at best range over tenant_id and test owner_user_id per row; PostgreSQL 16 has no btree skip scan to jump the unconstrained column.
- For ordering, the index is sorted by (status, updated_at) within a tenant and not by created_at, so the LIMIT cannot stop early: every matching row is read and then sorted. That is the 'Sort Method: top-N heapsort' line, and it is why the plan reads 2M rows to answer with 20.
- Derive the replacement from the access path — equality, equality, then the ordering column: CREATE INDEX CONCURRENTLY ON resource (tenant_id, owner_user_id, created_at DESC). The scan seeks to the (tenant, owner) range and walks 20 entries in order, so the Sort node disappears along with the row-read.
- Treat INCLUDE (title, status) as conditional, not free. An index-only scan still visits the heap for any row whose page is not marked all-visible, so on a table taking 1.2k writes/second the win depends on autovacuum keeping the visibility map current, and the wider index costs more on every insert.
Follow-up
- 90% of rows are status='active'. Would a partial index WHERE status = 'active' change your answer, and for which of the three queries?
- A dashboard runs this for 40 owners in one page load. What changes about the design?
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?
Explain the principles of signal modulation or Fourier transforms.
Explain the principles of signal modulation or Fourier transforms.
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 the differences between interfaces and classes in Java.
Describe the differences between interfaces and classes in Java.
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?
Can you explain key concepts in electromagnetism?
Can you explain key concepts in electromagnetism?
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 approach designing an object-oriented solution for a system like an elevator or a board game?
How would you approach designing an object-oriented solution for a system like an elevator or a board game?
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 architect a calculator component using React?
How would you architect a calculator component using React?
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 your approach to debugging a system under pressure.
Describe your approach to debugging a system under pressure.
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 SRC candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the SRC loop
- Write out the reported sequence: Recruiter Phone Screen, Technical Discussions, Panel or On-site Experience.
- 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 Behavioral Interviewing
- Spend the session on Behavioral Interviewing, which SRC candidates report being tested on.
- Write one worked example in Behavioral Interviewing and time yourself on it.
Deliverable: One timed worked example in Behavioral Interviewing.
03Work Technical Interviewing (Problem Solving)
- Spend the session on Technical Interviewing (Problem Solving), which SRC candidates report being tested on.
- Write one worked example in Technical Interviewing (Problem Solving) and time yourself on it.
Deliverable: One timed worked example in Technical Interviewing (Problem Solving).
04Work Algorithms
- Spend the session on Algorithms, which SRC candidates report being tested on.
- Write one worked example in Algorithms and time yourself on it.
Deliverable: One timed worked example in Algorithms.
05Answer out loud: Technical & Domain Knowledge
- Answer aloud, timed: Explain the principles of signal modulation or Fourier transforms.
- Answer aloud, timed: What is a hash map, and when would you choose to use one?
Deliverable: Spoken answers to 2 reported Technical & Domain Knowledge question(s), under time.
06Answer out loud: Behavioral & Cultural Fit
- Answer aloud, timed: Tell me about yourself and your interest in SRC.
- Answer aloud, timed: Describe a personal project you are particularly proud of.
Deliverable: Spoken answers to 2 reported Behavioral & Cultural Fit question(s), under time.
07Answer out loud: Problem-Solving & Coding
- Answer aloud, timed: Walk me through a simple algorithmic problem (LeetCode Easy level).
- Answer aloud, timed: Can you explain a complex technical topic to someone without a technical background?
Deliverable: Spoken answers to 2 reported Problem-Solving & Coding 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.
Tell me about yourself and your interest in SRC.
Tell me about yourself and your interest in SRC.
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 personal project you are particularly proud of.
Describe a personal project you are particularly proud of.
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?
Tell me about a time you had to overcome a significant technical challenge.
Tell me about a time you had to overcome a significant technical challenge.
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 handle working in a team environment where requirements may change?
How do you handle working in a team environment where requirements may change?
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?
Why do you want to work for a defense contractor?
Why do you want to work for a defense contractor?
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
Tell me about yourself and your interest in SRC.
- 02
Describe a personal project you are particularly proud of.
- 03
Tell me about a time you had to overcome a significant technical challenge.
- 04
How do you handle working in a team environment where requirements may change?
How difficult are the technical questions?
The technical questions are generally rated as average in difficulty. Focus on mastering foundational concepts rather than memorizing complex, obscure algorithms.
SRC Software Engineer candidate reports ↗What should I focus on for the "teach me something" portion?
Choose a topic you are genuinely passionate about, whether technical or non-technical. The goal is to show your ability to break down a concept, gauge your audience’s understanding, and communicate clearly.
SRC Software Engineer candidate reports ↗Is the company culture formal or relaxed?
SRC is known for a professional yet welcoming and collaborative culture. Expect interviewers to be friendly, but maintain a professional demeanor throughout.
SRC Software Engineer candidate reports ↗What is the typical timeline for an offer?
Timelines vary, but many candidates report receiving feedback or an offer within two weeks of their final interview round.
SRC Software Engineer candidate reports ↗What topics does SRC test in interviews?
SRC interviews most often cover Program Management, Stakeholder Management, Timeline Management, Stakeholder Communication, and Requirements Understanding. The exact emphasis depends on the specific role you apply for.
SRC 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.
- 01SRC 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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