As a Software Engineer at Cae, you are at the heart of the world’s leading training and simulation technology for civil aviation, defense, and healthcare. Your work directly impacts the safety and efficiency of global transportation and security by building high-fidelity simulators, training platforms, and complex software systems that mimic real-world environments. You aren't just writing code; you are bridging the gap between theoretical engineering and mission-critical operational reality. This role requires a blend of technical precision and systems-level thinking. Whether you are working on flight physics models, visual simulation engines, or data-driven training analytics, you will be solving problems that require high performance and extreme reliability. You will collaborate with multidisciplinary teams—including hardware engineers, subject matter experts, and other software specialists—to ensure that Cae remains at the forefront of simulation innovation. ##### Tip The work often involves legacy codebases combined with cutting-edge integration. Demonstrating an ability to balance clean code practices with the realities of long-term simulation projects is highly valued by hiring managers.
Screening Call
reportedInitial call with a recruiter to discuss your background and assess fit for the role.
What to demonstrate
- Initial call with a recruiter to discuss your background and assess fit for the role
- Depth in C++
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 Rounds
reportedOne or more technical interviews with team leads or hiring managers to evaluate technical skills.
What to demonstrate
- One or more technical interviews with team leads or hiring managers to evaluate technical skills
- Depth in C++
How to prepare
- Answer aloud and timed: What are your favorite design patterns and when do you apply them?
- Answer aloud and timed: How would you approach debugging a performance bottleneck in a real-time system?
Behavioral Discussion
reportedDiscussion focusing on interpersonal communication skills and personal project stories.
What to demonstrate
- Discussion focusing on interpersonal communication skills and personal project stories
- Depth in C++
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 discussion above and write down what you would ask to confirm before it.
Final Panel Interview
reportedFinal assessment combining technical and behavioral evaluations before a panel.
What to demonstrate
- Final assessment combining technical and behavioral evaluations before a panel
- Depth in C++
How to prepare
- Answer aloud and timed: How do you handle conflict or differing technical opinions within your team?
- Answer aloud and timed: Describe a project where you faced a significant technical hurdle; how did you overcome it?
PracHub editorial advice for the preparation topics above.
Know your resume
Be prepared to discuss every project you list in detail. You will be asked about your specific contributions, not just the team's output.
Prepare your questions
Always have insightful questions ready for the interviewers about the team's current challenges or the company's future in simulation technology.
Practice Bilinguality
In Canadian offices, be prepared for interviews to be conducted in both English and French.
Focus on clarity
Whether explaining a technical concept or a behavioral story, structure your answer to be concise and easy to follow.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
How do you manage memory in C++?
How do you manage memory in C++?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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?
Merge partitioned event streams into one ordered feed with bounded lateness
The read-model service consumes 64 log partitions carrying about 4,000 events per second in total. Each partition is ordered within itself, but partitions drift by up to 30 seconds, and the activity feed must present a tenant's events in occurred_at order. Produce the merge. State its complexity, the buffer it requires in events and in bytes, what happens when one partition is idle, and what you do with an event that arrives after you have already emitted its position. Payloads average 1 KB.
Approach
- Merge with a min-heap over the 64 partition heads keyed on (occurred_at, event_id): O(log P) per event and O(n log P) overall. The tie-break on event_id is what makes the output deterministic when two partitions carry the same millisecond, which matters because the feed is paginated and a non-deterministic order reorders pages under the reader.
- Emitting the heap head is only correct once every partition has produced everything up to that timestamp, so the emit condition is a watermark: the minimum across partitions of the highest occurred_at seen, less the allowed lateness. Events are held until the watermark passes them, which is what turns individually ordered streams into a jointly ordered one.
- Size the buffer from the lateness rather than guessing: 4,000 events per second times 30 seconds is 120,000 buffered events, and at 1 KB each about 120 MB of heap. That number is the real price of the ordering guarantee and belongs in front of whoever asked for it.
- Handle the idle partition explicitly, because it fails the feed rather than corrupting it: a partition with no traffic never advances its own maximum, so the watermark freezes and output stops entirely. Either every partition emits a periodic idle marker carrying the broker's current time, or the watermark falls back to wall clock for a partition silent beyond a threshold.
Follow-up
- The lateness budget is raised to five minutes. What is the new buffer, and what besides memory changes?
- The consumer restarts. Where does it resume from, and what does the feed look like for the first 30 seconds?
Diff a projection against the primary without per-row point reads
The listing projection has drifted and some rows show a stale version. The primary holds 40,000,000 resource rows across 12,000 tenants while serving 1,200 writes and 14,000 reads per second. The obvious repair, reading each resource row and comparing its version against the projection, is correct and would eventually finish. Explain precisely why it is unacceptable here, then give a diff that finds the differing rows, state its complexity, and make it safe to run against a live primary. Replication lag is usually under 100 ms and is not bounded.
Approach
- Quantify the naive cost rather than calling it slow: 40,000,000 point reads at even 0.5 ms each is over five hours serialised, and the only lever is concurrency, which is exactly what you cannot spend. The primary's pool is sized for the write path, and 40,000,000 random reads evict the buffer cache that sustains the 85 percent cache hit rate, so the audit degrades the system it is auditing.
- Replace random access with one ordered pass per side. Both sides can be read in (tenant_id, resource_id) order, which is a sequential scan on each and a merge join in O(n) time and O(1) memory. For a dense diff that is the whole answer, and it reads the primary once instead of 40,000,000 times.
- For the expected sparse case, compare range hashes instead of rows: partition the key space, compute per range an order-independent aggregate over hash(resource_id, version), compare aggregates, and descend only into ranges that differ. With d differing rows and branching factor B, at most d ranges mismatch per level, so the drill-down examines O(d log_B(n/d)) ranges and reads full rows only in mismatching leaves.
- Aggregate with a sum modulo 2^64 or a multiset hash, never XOR. XOR is order-independent but self-cancelling, so two rows wrong in the same way, or a row duplicated on one side, leave the range aggregate matching and the range is declared clean.
Follow-up
- The diff reports 900 stale rows. How do you decide between patching those rows and rebuilding the projection from resource_revision?
- Same job, but the projection lives in a search index that cannot be scanned in key order. What changes?
Replace offset paging on the resource feed with keyset
resource holds resource_id, tenant_id, owner_user_id, title, body_ref, version, status ('draft','active','archived','deleted'), created_at, updated_at, deleted_at, with an index on (tenant_id, status, updated_at DESC, resource_id DESC). The listing endpoint returns active resources for one tenant, newest update first, 50 per page, today with LIMIT 50 OFFSET n. Tenants reach page 400 and rows are created while they read. Write the keyset query, define what the cursor carries and how it is encoded, and say which part of the index each predicate uses. Assume PostgreSQL 16.
Approach
- Name the two failures separately. OFFSET 20000 makes the server produce and discard 20,000 rows, so page cost grows with depth rather than with page size. Independently, any write that changes how many rows sort above the offset moves the window between two fetches, and the direction decides which anomaly you get: an insert lands at the head of updated_at DESC and pushes already-returned rows down past the boundary, so they are returned a second time; a delete above the offset, or a row whose updated_at is bumped above the cursor, pulls rows up and one is never returned at all. Nothing in the response reveals either.
- Write the seek: WHERE tenant_id = $1 AND status = 'active' AND (updated_at, resource_id) < ($2, $3) ORDER BY updated_at DESC, resource_id DESC LIMIT 50. The row-value comparison is one index range rather than a disjunction, and both columns are NOT NULL, which is what makes that comparison well defined.
- Map each predicate onto the index: tenant_id and status are equality on the leading columns, (updated_at, resource_id) is the range, and the ORDER BY matches the index order so no Sort node appears and the scan stops after 50 rows. The DESC in the definition only matters for mixed directions — a plain ascending btree on the same columns is read backwards for this query.
- Put both sort columns in the cursor and nothing the client can tamper with into another tenant: base64 of (updated_at, resource_id), validated server-side, with tenant_id taken from the principal.
Follow-up
- The client asks for 'jump to page 400'. What do you offer instead, and what does the honest version cost?
- Sort order becomes user-selectable across four columns. How many indexes is that, and which would you refuse to add?
Hold a per-tenant active cap against concurrent creates
A tenant on the standard plan may hold at most 50 resources with status='active'. The create handler runs SELECT count(*) FROM resource WHERE tenant_id = $1 AND status = 'active', compares to 50, then inserts. Two creates arrive 3 ms apart on different instances and the tenant lands at 51. Name the anomaly, say whether PostgreSQL 16 READ COMMITTED or REPEATABLE READ prevents it and why, then give an implementation that holds the cap at READ COMMITTED with the exact statements. Finally, say what changes when the cap is 'at most one running export per tenant' on job_run.
Approach
- Name it: write skew. The two transactions read an overlapping set and write disjoint rows, so there is no row-level conflict for the engine to detect and each commit is individually legal.
- Rule out the levels precisely. READ COMMITTED takes a fresh snapshot per statement and takes no lock on the counted rows, so both see 49. PostgreSQL's REPEATABLE READ is snapshot isolation: it removes non-repeatable reads and phantoms within the snapshot but still admits write skew, because the anomaly is not a re-read of a changed row, it is a read of a set that a concurrent transaction invalidates. Only SERIALIZABLE closes it, by tracking the read dependency and aborting one transaction with SQLSTATE 40001 — a guarantee that exists only if the application re-runs the whole transaction from the read.
- Convert the set predicate into a single-row conflict: keep tenant.active_resource_count and run UPDATE tenant SET active_resource_count = active_resource_count + 1 WHERE tenant_id = $1 AND active_resource_count < 50 in the same transaction as the INSERT. Zero affected rows is the cap, returned as 409. The row lock serialises the decision at any isolation level, and contention is bounded to one tenant's row — which is also the fair-scheduling unit, unlike a global counter that would convoy every tenant behind one row.
- State the cost you just took on: a counter is a second source of truth that can drift, so every path that changes status must adjust it inside the same transaction, and a periodic reconciliation has to exist, with resource_revision as the authority for what the count should have been.
Follow-up
- A resource moves from archived back to active. Which statements change, and what breaks if the counter update and the status change land in different transactions?
- The cap becomes plan-dependent and a plan can change mid-month. Where does the number 50 live, and who reads it?
Explain the difference between a class and an object, inheritance, and polymorphism.
Explain the difference between a class and an object, inheritance, and polymorphism.
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?
What are your favorite design patterns and when do you apply them?
What are your favorite design patterns and when do you apply them?
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 the basic concepts of aircraft electronics or simulator architecture?
Can you explain the basic concepts of aircraft electronics or simulator architecture?
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?
How would you design a software solution if the project scope was initially unclear?
How would you design a software solution if the project scope was initially unclear?
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?
How do you manage trade-offs between system performance, cost, and development time?
How do you manage trade-offs between system performance, cost, and development time?
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 a complex project from your past experience and your specific contribution to it.
Walk me through a complex project from your past experience and your specific contribution to it.
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?
How would you approach debugging a performance bottleneck in a real-time system?
How would you approach debugging a performance bottleneck in a real-time system?
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 Cae candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Cae loop
- Write out the reported sequence: Screening Call, Technical Rounds, Behavioral Discussion, Final 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.
02Work C++
- Spend the session on C++, which Cae candidates report being tested on.
- Write one worked example in C++ and time yourself on it.
Deliverable: One timed worked example in C++.
03Work JavaScript
- Spend the session on JavaScript, which Cae candidates report being tested on.
- Write one worked example in JavaScript and time yourself on it.
Deliverable: One timed worked example in JavaScript.
04Work Problem-solving (coding assessment)
- Spend the session on Problem-solving (coding assessment), which Cae candidates report being tested on.
- Write one worked example in Problem-solving (coding assessment) and time yourself on it.
Deliverable: One timed worked example in Problem-solving (coding assessment).
05Answer out loud: Technical and Domain Knowledge
- Answer aloud, timed: Explain the difference between a class and an object, inheritance, and polymorphism.
- Answer aloud, timed: How do you manage memory in C++?
Deliverable: Spoken answers to 2 reported Technical and Domain Knowledge question(s), under time.
06Answer out loud: Behavioral and Situational
- Answer aloud, timed: Tell me about a time you had to deal with an unrealistic project deadline.
- Answer aloud, timed: How do you handle conflict or differing technical opinions within your team?
Deliverable: Spoken answers to 2 reported Behavioral and Situational question(s), under time.
07Answer out loud: System Design and Problem Solving
- Answer aloud, timed: How would you design a software solution if the project scope was initially unclear?
- Answer aloud, timed: How do you manage trade-offs between system performance, cost, and development time?
Deliverable: Spoken answers to 2 reported System Design and Problem Solving 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 a time you had to deal with an unrealistic project deadline.
Tell me about a time you had to deal with an unrealistic project deadline.
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 conflict or differing technical opinions within your team?
How do you handle conflict or differing technical opinions within your team?
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 project where you faced a significant technical hurdle; how did you overcome it?
Describe a project where you faced a significant technical hurdle; how did you overcome 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?
If you realize a project cannot be completed on time, what is your immediate plan of action?
If you realize a project cannot be completed on time, what is your immediate plan of action?
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?
What do you value most in a workplace culture?
What do you value most in a workplace culture?
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 a time you had to deal with an unrealistic project deadline.
- 02
How do you handle conflict or differing technical opinions within your team?
- 03
Describe a project where you faced a significant technical hurdle; how did you overcome it?
- 04
If you realize a project cannot be completed on time, what is your immediate plan of action?
Is the technical interview very difficult?
The difficulty is generally moderate. The goal is not to stump you with "trick" questions, but to gauge your fundamental understanding of programming and your ability to think logically.
Cae Software Engineer candidate reports ↗How long does the hiring process take?
Timelines can vary significantly based on location and security requirements. Expect a few weeks from the initial screen to a final decision, though background checks can extend this period.
Cae Software Engineer candidate reports ↗Is there a lot of travel involved?
Depending on the specific team, some roles may require travel to simulator installation sites. It is perfectly acceptable to ask about this during your interview.
Cae Software Engineer candidate reports ↗What should I do if I don't know the answer to a technical question?
Be honest about your knowledge gap but show your thought process. Explain how you would go about finding the answer or what principles you would use to approach the problem.
Cae Software Engineer candidate reports ↗What topics does Cae test in interviews?
Cae interviews most often cover Communication Skills, Stakeholder Management, Time Management, Problem Solving, and JavaScript. The exact emphasis depends on the specific role you apply for.
Cae 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.
- 01Cae 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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