As a Software Engineer at SciTec, you will play a vital role in building advanced software systems for national security, defense, and scientific applications. This position demands a combination of rigorous engineering principles and domain-specific knowledge, often involving complex data processing, numerical algorithms, and real-time mission support systems. Your work directly enables teams to process large volumes of sensor and operational data quickly and accurately. The role covers a diverse spectrum of problem spaces, ranging from core C++ and Rust application development to cloud infrastructure, DevSecOps, and numerical algorithm design. Because SciTec operates heavily within defense contracting and technical R&D, you will often collaborate with scientists, systems engineers, and defense stakeholders. You'll work on projects that require high performance, reliability, and precision, making this an ideal environment if you enjoy solving difficult algorithmic and structural problems. Expect a fast-moving, technically demanding workplace where engineering rigor is paramount. While projects can be complex, you will find a collaborative culture of smart peers who care deeply about mission execution. Success in this role requires strong foundational computer science skills, adaptability across modern tech stacks, and a readiness to dive deep into both low-level implementation details and high-level architecture.
Phone Screen
reportedInitial phone screening to evaluate candidate's background and fit for the role.
What to demonstrate
- Initial phone screening to evaluate candidate's background and 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 Coding Assignment
reportedCandidates complete a technical coding assignment to demonstrate their skills.
What to demonstrate
- Candidates complete a technical coding assignment to demonstrate their skills
- Depth in C++
How to prepare
- Answer aloud and timed: 1–2 sentences introducing the category and what it tests.
- Answer aloud and timed: Bullet list of realistic example questions: How would you architect a scalable ingestion pipeline for high-throughput sensor data? What strategies do you use for containerizing and deploying applications securely in a cloud environment? How do you design distributed systems that maintain resilience under intermittent network connectivity? Explain your approach to designing a modular software framework that accommodates rapidly changing scientific requirements.
In-Person Interviews
reportedSuccessful candidates participate in in-person interviews with technical challenges and behavioral assessments.
What to demonstrate
- Successful candidates participate in in-person interviews with technical challenges and behavioral assessments
- Depth in C++
How to prepare
- Answer aloud and timed: 1–2 sentences introducing the category and what it tests.
- Answer aloud and timed: Bullet list of realistic example questions: Can you walk me through your background and highlight a project where you solved a complex technical bottleneck? Tell me about a time when project requirements were ambiguous. How did you proceed? How do you handle disagreements on technical direction within a multidisciplinary team? Describe a situation where you had to balance delivery speed with engineering quality.
PracHub editorial advice for the preparation topics above.
Treat the take-home project as a production artifact
Write clean, readable code, include clear documentation or README files, and ensure your submission handles edge cases gracefully, as reviewers examine this work closely.
Be ready to discuss trade-offs
Interviewers appreciate candidates who can articulate why they chose a particular data structure, memory management strategy, or architectural pattern over alternatives.
Brush up on language specifics
Whether your interview focuses on C++, Rust, or Python, ensure you know the language's modern idioms, memory safety rules, and performance characteristics inside and out.
Communicate your thought process
During live technical or behavioral rounds, explain your assumptions out loud so the panel can follow your reasoning, especially when tackling ambiguous problems.
Connect your experience to the mission
Highlight past projects where you handled complex data pipelines, high-throughput systems, or demanding performance constraints to show direct relevance to SciTec's work.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
1–2 sentences introducing the category and what it tests.
1–2 sentences introducing the category and what it tests.
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?
Bullet list of realistic example questions: What are the access modifiers in C++ and how do they affect inheri
Bullet list of realistic example questions: What are the access modifiers in C++ and how do they affect inheritance? Can you explain the difference between stack and heap allocation in C++ or Java? How do you manage memory safety and lifetimes when writing concurrent code in Rust? What are some common pitfalls when dealing with numerical precision and floating-point arithmetic? How do you optimize a data-transformation pipeline for performance in C++ or Python?
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?
Identify the heaviest tenants in a five-minute window under memory pressure
The edge service handles about 3,000 requests per second across roughly 50,000 tenants, peaking near 9,000. Expose the 50 heaviest tenants by request count over the trailing five minutes so limits can be tightened before one tenant's backfill starves the fleet. You may not retain five minutes of raw records. Give the exact solution and its memory, then the bounded-memory approximation with its error stated as a formula, and say which you would ship and at what tenant cardinality that choice changes.
Approach
- Do the exact version first, because it is affordable at this cardinality: a ring of 300 one-second counters per tenant, advanced lazily, is 1,200 bytes of counters per tenant and roughly 60 to 90 MB for 50,000 tenants with overhead. Carry a running total and subtract the bucket you overwrite so a window read is O(1) rather than 300 adds.
- Extract the top 50 with a size-k min-heap over the tenant sums: O(d log k) for d tenants, against O(d log d) to sort them all. Maintaining the heap continuously instead of on query requires a tenant-to-heap-index map, because incrementing a count already inside the heap means sifting from a known position, and without that map you rebuild the heap on every request.
- State the approximation precisely rather than gesturing at sketches. Misra-Gries with m counters retains every item whose true count exceeds N/(m+1), and each retained count underestimates the truth by at most N/(m+1). With m = 1,000 and N = 900,000 requests in the window the error is roughly 900 requests, which is fine for spotting a tenant sending 50,000 and useless for ranking two tenants 200 apart.
- Say what breaks when the window slides: Misra-Gries and Space-Saving are insert-only and cannot be decremented as records age out. The workable construction is one summary per sub-window, say ten seconds, with 30 summaries merged at query time, and the merged error is the sum of the per-summary errors, so the bound degrades linearly in the number of sub-windows.
Follow-up
- The heaviest tenant is heavy because of one export job rather than user traffic. Should the limiter treat those as the same tenant?
- Two tenants sit tied at the boundary of the top 50. Does your answer flap, and does the flapping matter?
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?
Write the update path that detects a concurrent edit
resource carries version INT NOT NULL DEFAULT 1. resource_revision holds revision_id, resource_id, version, actor_user_id, change_kind, patch JSONB, request_id, created_at with UNIQUE (resource_id, version). outbox_event holds aggregate_type, aggregate_id, aggregate_version, event_type, payload, status. A PUT carries the version the client read. Write the exact statements for the single transaction that applies the edit, records the revision and enqueues 'resource.updated', and give the handler's branch on zero affected rows. Then say what PostgreSQL 16 does under READ COMMITTED when two of these updates hit one row at once.
Approach
- One transaction, three writes, no network call inside it: UPDATE resource SET title = $3, version = version + 1, updated_at = now() WHERE resource_id = $1 AND tenant_id = $4 AND version = $2; then INSERT the resource_revision row at version $2 + 1; then INSERT the outbox_event row at the same aggregate_version. The event goes to a table rather than a broker because no transaction spans both.
- Branch on the affected-row count before doing anything else. Zero has three causes — stale version, wrong tenant, row gone — so re-read once and map to 409 carrying the current version, or 404 for an id outside the caller's tenant, which also stops the endpoint confirming that another tenant's id exists.
- State the engine behaviour instead of assuming it. Under READ COMMITTED the second UPDATE blocks on the row lock, and when the first commits PostgreSQL re-evaluates the WHERE clause against the newly committed row, so the version predicate now fails and the statement reports zero rows. Under REPEATABLE READ the identical collision raises SQLSTATE 40001 instead, so the handler must fold both shapes into one conflict response.
- Keep UNIQUE (resource_id, version) even though the predicate already serialises writers. It is what makes a lost update unwritable if any other path ever reaches the revision table, and it converts a logic bug into 23505 rather than into a silently missing history row.
Follow-up
- A client sends the version it read ten minutes ago and the resource has moved three versions. What is in your 409 so it can resolve the conflict without a full re-fetch?
- Two editors, two disjoint fields, no overlap. Does your answer still refuse the second write, and should it?
1–2 sentences introducing the category and what it tests.
1–2 sentences introducing the category and what it tests.
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?
Bullet list of realistic example questions: How would you architect a scalable ingestion pipeline for high-thr
Bullet list of realistic example questions: How would you architect a scalable ingestion pipeline for high-throughput sensor data? What strategies do you use for containerizing and deploying applications securely in a cloud environment? How do you design distributed systems that maintain resilience under intermittent network connectivity? Explain your approach to designing a modular software framework that accommodates rapidly changing scientific requirements.
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?
Edge instances grow 400 MB per hour until the nightly restart
Edge API instances start at 700 MB resident and grow about 400 MB/hour; a nightly rolling restart has hidden it for weeks. Growth continues unchanged when request rate halves overnight, p99 degrades in the last hours before an instance is recycled, and heap used immediately after a forced full GC rises monotonically. The service holds no product state. Name the discriminating measurement that separates the plausible causes, give the most likely cause, and give the fix and how you would verify it.
Approach
- Separate resident memory from live heap first, because they fail differently. Resident size can grow from fragmentation, native buffers or thread stacks while the heap is flat; heap used after a full GC rising monotonically is the measurement that says objects are reachable and not being released. You already have it, so this is retention, not fragmentation, and that closes off half the candidate list.
- Use the rate's independence from traffic as the discriminator. Growth that continues at half the request rate rules out per-request objects that are merely slow to collect and points at a structure that grows with distinct values observed rather than with call volume. Write the candidates that have that property: a metrics registry keyed on a high-cardinality label, an unevicted cache, an interner, a per-key lock map.
- Take two heap snapshots an hour apart and diff by retained size, reading the dominator tree, not by allocation count or instance count. Expect one root holding a map with millions of entries, then follow the reference chain to the code that inserts and never removes. Allocation profilers point at churn, which is the wrong signal here.
- The candidate that fits this service is an observability label carrying an identifier, such as a request path recorded before templating so that /v1/resources/48213 becomes its own metric series. That grows with distinct ids seen, is independent of rate, and explains the late p99 degradation, since GC cost rises with the size of the live set.
Follow-up
- Post-GC heap is now flat but resident size still creeps. What are you looking at, and does it matter?
- How would you have detected this before an OOM, given the nightly restart masked the trend?
Built from the rounds and topics SciTec candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the SciTec loop
- Write out the reported sequence: Phone Screen, Technical Coding Assignment, In-Person Interviews.
- 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 C++
- Spend the session on C++, which SciTec candidates report being tested on.
- Write one worked example in C++ and time yourself on it.
Deliverable: One timed worked example in C++.
03Work Take-home coding assessments
- Spend the session on Take-home coding assessments, which SciTec candidates report being tested on.
- Write one worked example in Take-home coding assessments and time yourself on it.
Deliverable: One timed worked example in Take-home coding assessments.
04Work DevSecOps
- Spend the session on DevSecOps, which SciTec candidates report being tested on.
- Write one worked example in DevSecOps and time yourself on it.
Deliverable: One timed worked example in DevSecOps.
05Answer out loud: Technical and Language Fundamentals
- Answer aloud, timed: 1–2 sentences introducing the category and what it tests.
- Answer aloud, timed: Bullet list of realistic example questions: What are the access modifiers in C++ and how do they affect inheritance? Can you explain the difference between stack and heap allocation in C++ or Java? How do you manage memory safety and lifetimes when writing concurrent code in Rust? What are some common pitfalls when dealing with numerical precision and floating-point arithmetic? How do you optimize a data-transformation pipeline for performance in C++ or Python?
Deliverable: Spoken answers to 2 reported Technical and Language Fundamentals question(s), under time.
06Answer out loud: System Design and Architecture
- Answer aloud, timed: 1–2 sentences introducing the category and what it tests.
- Answer aloud, timed: Bullet list of realistic example questions: How would you architect a scalable ingestion pipeline for high-throughput sensor data? What strategies do you use for containerizing and deploying applications securely in a cloud environment? How do you design distributed systems that maintain resilience under intermittent network connectivity? Explain your approach to designing a modular software framework that accommodates rapidly changing scientific requirements.
Deliverable: Spoken answers to 2 reported System Design and Architecture question(s), under time.
07Answer out loud: Behavioral and Background Discussion
- Answer aloud, timed: 1–2 sentences introducing the category and what it tests.
- Answer aloud, timed: Bullet list of realistic example questions: Can you walk me through your background and highlight a project where you solved a complex technical bottleneck? Tell me about a time when project requirements were ambiguous. How did you proceed? How do you handle disagreements on technical direction within a multidisciplinary team? Describe a situation where you had to balance delivery speed with engineering quality.
Deliverable: Spoken answers to 2 reported Behavioral and Background Discussion 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.
1–2 sentences introducing the category and what it tests.
1–2 sentences introducing the category and what it tests.
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?
Bullet list of realistic example questions: Can you walk me through your background and highlight a project wh
Bullet list of realistic example questions: Can you walk me through your background and highlight a project where you solved a complex technical bottleneck? Tell me about a time when project requirements were ambiguous. How did you proceed? How do you handle disagreements on technical direction within a multidisciplinary team? Describe a situation where you had to balance delivery speed with engineering quality.
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?
Turn a code review disagreement into a decision
A colleague's change updates a row with UPDATE resource SET version = version + 1 WHERE resource_id = $1 AND version = $2 and treats an affected-row count of zero as a successful no-op. You read that as a silently lost update; they think returning 200 is friendlier to clients than returning a conflict. Describe how you have handled a review disagreement of this shape: what goes in the comment, when you leave the thread, and who decides. Then write the comment you would leave here, in under 80 words.
Approach
- Sort the disagreement before writing anything. A silently discarded write is a correctness claim about data; the choice between 409 and 412 is taste. Only the first justifies blocking a merge, and saying which one you are doing is most of the value of the comment.
- Make the claim reproducible in the comment itself with an interleaving rather than a principle: A reads version 7, B reads version 7, B commits version 8, A's predicate matches zero rows, A is told it succeeded and A's edit is gone.
- Offer the alternative with its cost attached: return 409 carrying the current version and the revision that won, so the client can re-read and re-apply. Note that automatic retry is not the fix, because a retry re-reads the winner's state and reapplies an intent formed against data that no longer exists.
- Apply an escalation rule you can state: two round trips on the thread, then a call, and the service's owner decides rather than the reviewer. A reviewer who cannot be overruled is a bottleneck with extra steps.
Follow-up
- Where would you put the test that fails if someone reintroduces the swallowed zero rowcount?
- The author says clients cannot handle a 409. How do you check whether that is true?
- 01
1–2 sentences introducing the category and what it tests.
- 02
Bullet list of realistic example questions: Can you walk me through your background and highlight a project where you solved a complex technical bottleneck? Tell me about a time when project requirements were ambiguous. How did you proceed? How do you handle disagreements on technical direction within a multidisciplinary team? Describe a situation where you had to balance delivery speed with engineering quality.
- 03
A colleague's change updates a row with UPDATE resource SET version = version + 1 WHERE resource_id = $1 AND version = $2 and treats an affected-row count of zero as a successful no-op. You read that as a silently lost update; they think returning 200 is friendlier to clients than returning a conflict. Describe how you have handled a review disagreement of this shape: what goes in the comment, when you leave the thread, and who decides. Then write the comment you would leave here, in under 80 words.
How difficult is the interview process and how much preparation time should I expect?
The interview process is moderately rigorous, requiring a solid grasp of programming fundamentals, a time investment for a take-home coding project, and panel discussions. Expect to spend several hours on the take-home assessment alone, alongside time reviewing core language features and system design principles.
SciTec Software Engineer candidate reports ↗What distinguishes successful candidates from those who are not selected?
Successful candidates demonstrate deep technical competence in their primary language—such as C++ or Rust—alongside clean, well-documented code in their take-home assignments. They also communicate their problem-solving rationale clearly and show genuine enthusiasm for the complex domain problems tackled at SciTec.
SciTec Software Engineer candidate reports ↗What is the company culture like for engineering teams?
The culture is mission-focused, collaborative, and grounded in engineering rigor. Teams consist of dedicated professionals working on specialized technical challenges, creating an environment where technical depth and intellectual curiosity are highly valued.
SciTec Software Engineer candidate reports ↗What is the typical hiring timeline from initial screen to final offer?
While the process can sometimes move swiftly, candidates should be prepared for potential variability in scheduling and communication timelines. It is advisable to maintain proactive communication with your recruiting contact regarding status updates and next steps.
SciTec Software Engineer candidate reports ↗Are there remote or hybrid work options available?
Work arrangements depend heavily on the specific team, project requirements, and security clearance needs. Many roles are centered around office locations like Boulder, Colorado, while certain infrastructure or cloud positions may offer flexible or remote configurations.
SciTec Software Engineer candidate reports ↗What topics does SciTec test in interviews?
SciTec interviews most often cover Change Management, Windows Server Administration, C++, STIGs (Security Technical Implementation Guides), and Program/Project Management. The exact emphasis depends on the specific role you apply for.
SciTec 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.
- 01SciTec 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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