As a Software Engineer at Barco, you are at the intersection of high-end hardware innovation and mission-critical software solutions. Barco is a global leader in visualization and projection technology, and your role is to develop the software that powers these complex systems. Whether you are working on medical imaging, cinema projection, or control room solutions, your code directly impacts the reliability and performance of products that users rely on in high-stakes environments. This role requires a blend of deep technical expertise and a systems-thinking mindset. You will be expected to bridge the gap between low-level hardware interactions and high-level application logic. Because Barco products are often specialized and highly integrated, you will work in cross-functional teams where your ability to understand the full development lifecycle—from architecture and design to deployment—is essential. You aren't just writing features; you are building the backbone of technology that defines how the world sees information.
Initial Screening
reportedAn initial screening with either a recruiter or a hiring manager to assess basic qualifications.
What to demonstrate
- An initial screening with either a recruiter or a hiring manager to assess basic qualifications
- Depth in Data Structures and Algorithms (DSA)
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 rounds that may include coding assessments, system design discussions, or deep dives into previous work.
What to demonstrate
- One or more technical rounds that may include coding assessments, system design discussions, or deep dives into previous work
- Depth in Data Structures and Algorithms (DSA)
How to prepare
- Answer aloud and timed: Can you explain buildroot and how it compares to yocto?
- Answer aloud and timed: What are closures in JavaScript? Provide an example.
Behavioral Rounds
reportedInterviews focusing on project management experience and team collaboration.
What to demonstrate
- Interviews focusing on project management experience and team collaboration
- Depth in Data Structures and Algorithms (DSA)
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 rounds above and write down what you would ask to confirm before it.
PracHub editorial advice for the preparation topics above.
Own your resume
Every line on your resume is fair game. If you list a project, be prepared to explain the architecture, the bugs you fixed, and the lessons you learned.
Prepare for the "Why
Barco interviewers value candidates who understand the reasoning behind technical choices. Don't just provide a solution; provide the justification.
Practice your communication
Use the STAR method (Situation, Task, Action, Result) to structure your behavioral answers. This ensures your stories are concise and impactful.
Be ready for whiteboard/code sharing
Whether in-person or virtual, be prepared to write code or design systems while explaining your thought process aloud.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Explain the difference between Multiprocessing and Multithreading.
Explain the difference between Multiprocessing and Multithreading.
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?
What are closures in JavaScript? Provide an example.
What are closures in JavaScript? Provide an example.
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?
Explain the concept of Smart Pointers and virtual functions in C++.
Explain the concept of Smart Pointers and virtual functions 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?
Denormalise tenant onto revisions and backfill it live
resource_revision (revision_id, resource_id, version, actor_user_id, change_kind, patch, request_id, created_at) has 400M rows and no tenant column; tenant_id lives only on resource. Two reads need it: a tenant-scoped audit feed ordered by created_at DESC, and an offboarding purge. Both join back to resource today. Justify adding tenant_id to resource_revision against those two reads, name the anomaly the copy introduces and the constraint that prevents it, then give the ordered migration for a live table taking 1.2k writes/second — the lock each step takes, how the backfill is batched, and where each step stops being reversible. PostgreSQL 16.
Approach
- Justify from the access path rather than from taste. Without the column, the audit feed either scans resource_revision by created_at and discards other tenants' rows, or resolves the tenant's resource_ids first and probes with them — both proportional to the tenant's whole history rather than to one page. With (tenant_id, created_at DESC, revision_id DESC) it is a seek that stops at 50 rows, and the purge becomes a ranged delete instead of a join.
- Name the cost exactly: a second copy of a fact can disagree with the first. Make the disagreement unwritable rather than documented — add UNIQUE (resource_id, tenant_id) on resource so it can serve as a foreign-key target, then FOREIGN KEY (resource_id, tenant_id) REFERENCES resource (resource_id, tenant_id) on the revision table. A revision can then only ever carry its parent's tenant.
- Step one, expand: ALTER TABLE resource_revision ADD COLUMN tenant_id BIGINT NULL, with no default, so it is a catalogue change and no rewrite. It still needs ACCESS EXCLUSIVE for an instant, and that instant queues behind the longest open transaction on the table while every later query queues behind it — set lock_timeout to 2s and retry rather than wait.
- Step two, dual-write: deploy the writer that populates tenant_id on every new revision while reads still use the join. Reversible by redeploying the previous build, because nothing reads the column yet.
Follow-up
- The backfill is half finished and a rollback is required. What state is the table in, and what does the previous build do with a half-populated column?
- How do you verify the backfill actually finished, given rows are still being inserted while it runs?
Find version gaps and relay lag with window functions
outbox_event holds event_id, aggregate_type, aggregate_id, aggregate_version, event_type, payload, status ('pending','published','dead'), attempts, created_at, published_at. A projection is missing rows and you must decide whether the relay skipped events or the consumer dropped them. Write three queries over the last seven days: one listing every aggregate_id whose published aggregate_version sequence has a hole, one giving per-day counts with a running total, and one returning the newest published event per aggregate. For each, say where the window function is evaluated relative to WHERE and LIMIT. PostgreSQL 16.
Approach
- Gaps: compute lead(aggregate_version) OVER (PARTITION BY aggregate_id ORDER BY aggregate_version) in a subquery, then filter next_version <> aggregate_version + 1 in the outer query. Window functions are evaluated after WHERE, GROUP BY and HAVING and before the outer ORDER BY and LIMIT, so the predicate cannot sit in the same WHERE clause and PostgreSQL 16 has no QUALIFY.
- Say what the seven-day filter does to the answer: it truncates every partition, so the first row per aggregate has no predecessor inside the window and a hole spanning the boundary is invisible. Widen the window, or join to resource.version as the authority for the true maximum.
- Running total: SELECT date_trunc('day', created_at) AS d, count() AS n, sum(count()) OVER (ORDER BY date_trunc('day', created_at) ROWS UNBOUNDED PRECEDING). An aggregate inside a window call is legal because grouping runs before windowing. The grouping key is unique per row here so ROWS and RANGE agree, but write the frame anyway — over ungrouped rows with tied timestamps the default RANGE frame pulls in every peer row and the total jumps.
- Newest per aggregate: DISTINCT ON (aggregate_id) ... ORDER BY aggregate_id, aggregate_version DESC is the cheap PostgreSQL-only form when an index matches that order; row_number() OVER (PARTITION BY aggregate_id ORDER BY aggregate_version DESC) = 1 is the portable form and needs a subquery for the same evaluation-order reason as the gap query.
Follow-up
- Relay failover redelivers events. Does a duplicate break the gap query, and how would you detect one from this table alone?
- Turn the gap check into a continuous monitor rather than a query someone runs after an incident. What does it watch?
What is the Event Loop in JavaScript, and how do the call stack, microtask queue, and callback queue interact?
What is the Event Loop in JavaScript, and how do the call stack, microtask queue, and callback queue interact?
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 buildroot and how it compares to yocto?
Can you explain buildroot and how it compares to yocto?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
How do you implement Design Patterns in your projects?
How do you implement Design Patterns in your projects?
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?
Design a scalable API for handling user lifecycle events.
Design a scalable API for handling user lifecycle events.
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 create a High Availability (HA) web application hosting environment on-premises?
How would you create a High Availability (HA) web application hosting environment on-premises?
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 data modeling, versioning, and authentication in backend systems.
Describe your approach to data modeling, versioning, and authentication in backend systems.
Approach
- Say who the caller is and what they do when the call fails halfway.
- Define the identity of a request so a retry cannot double-apply it.
- Separate accepted, pending, failed and confirmed; they are different facts.
- 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?
Read latency spikes on a sixty-second sawtooth
The cached listing read path serves about 14k reads/second at an 85% hit rate. p99 sits at 35 ms for 57 seconds, jumps to 900 ms for 3, and repeats. During each spike the primary shows several hundred identical listing queries starting within the same millisecond, all carrying one large tenant's id. Cache entries use a 60-second TTL. Give the mechanism, the ordered checks, the fix, and the correctness hazard your fix must not introduce.
Approach
- Match the period to a configured number before theorising about load. A spike every 60 seconds against a 60-second TTL is an entry expiring, and you confirm it by correlating spike timestamps with the entry's write time rather than with the traffic curve. If the period had matched a cron or a GC interval instead, this is a different investigation.
- Establish the concurrency of the miss. Several hundred identical queries in one millisecond means the miss path has no coalescing: every request that arrives between expiry and repopulation recomputes. The herd size is that key's arrival rate times its recompute time, so at 1.2k reads/second for the hot key and a 250 ms recompute you expect about 300 concurrent misses, which matches what is observed.
- Add single-flight on the miss path so one caller per key recomputes under a short-lived lock while the rest wait for its result. Prefer stale-while-revalidate where the read tolerates it: return the expired value immediately and refresh asynchronously, which removes the latency spike rather than serialising it into a queue of waiters.
- De-synchronise the keys. Write TTLs with jitter, for example 60 seconds plus or minus 10%, so a deploy or a mass invalidation does not align every key on the same second and turn a per-key herd into a fleet-wide one.
Follow-up
- The same sawtooth appears on a key that is invalidated on write rather than expired. Is that the same bug?
- How does your answer change if the recompute takes 4 seconds instead of 250 ms?
Built from the rounds and topics Barco candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Barco loop
- Write out the reported sequence: Initial Screening, Technical Rounds, Behavioral Rounds.
- 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 Data Structures and Algorithms (DSA)
- Spend the session on Data Structures and Algorithms (DSA), which Barco candidates report being tested on.
- Write one worked example in Data Structures and Algorithms (DSA) and time yourself on it.
Deliverable: One timed worked example in Data Structures and Algorithms (DSA).
03Work JavaScript
- Spend the session on JavaScript, which Barco candidates report being tested on.
- Write one worked example in JavaScript and time yourself on it.
Deliverable: One timed worked example in JavaScript.
04Work System Design
- Spend the session on System Design, which Barco candidates report being tested on.
- Write one worked example in System Design and time yourself on it.
Deliverable: One timed worked example in System Design.
05Answer out loud: Technical & Domain Knowledge
- Answer aloud, timed: Explain the difference between Multiprocessing and Multithreading.
- Answer aloud, timed: What is the Event Loop in JavaScript, and how do the call stack, microtask queue, and callback queue interact?
Deliverable: Spoken answers to 2 reported Technical & Domain Knowledge question(s), under time.
06Answer out loud: System Design & Architecture
- Answer aloud, timed: Design a scalable API for handling user lifecycle events.
- Answer aloud, timed: How would you create a High Availability (HA) web application hosting environment on-premises?
Deliverable: Spoken answers to 2 reported System Design & Architecture question(s), under time.
07Answer out loud: Behavioral & Career Growth
- Answer aloud, timed: Where do you see yourself in 5 years?
- Answer aloud, timed: Tell me about a time you had to deal with a supplier or stakeholder who could not deliver on time.
Deliverable: Spoken answers to 2 reported Behavioral & Career Growth 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.
Where do you see yourself in 5 years?
Where do you see yourself in 5 years?
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 deal with a supplier or stakeholder who could not deliver on time.
Tell me about a time you had to deal with a supplier or stakeholder who could not deliver on time.
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 are you interested in joining Barco?
Why are you interested in joining Barco?
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 your last technical experience and the most challenging project you have worked on.
Tell me about your last technical experience and the most challenging project you have worked on.
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
Where do you see yourself in 5 years?
- 02
Tell me about a time you had to deal with a supplier or stakeholder who could not deliver on time.
- 03
Why are you interested in joining Barco?
- 04
Tell me about your last technical experience and the most challenging project you have worked on.
How long does the interview process usually take?
The process can vary significantly depending on the team and location, ranging from a few weeks to several months. Stay proactive and follow up if you haven't heard back within the expected timeframe.
Barco Software Engineer candidate reports ↗Is the technical interview focused on theory or practice?
It is a mix of both. You will face questions on core computer science theory, but you will also be asked to apply that knowledge to real-world scenarios or explain your own projects in detail.
Barco Software Engineer candidate reports ↗What is the best way to stand out during the interview?
Demonstrate a "systems mindset." Don't just answer the question; explain how your answer fits into the broader architecture of a product and why it is the most efficient or maintainable choice.
Barco Software Engineer candidate reports ↗Does Barco support remote work?
Expectations regarding remote or hybrid work vary by role and location. Always clarify the specific requirements for your position during the recruiter screen.
Barco Software Engineer candidate reports ↗What topics does Barco test in interviews?
Barco interviews most often cover Data-Driven Decision Making, Stakeholder Management, Problem Solving, Data Structures and Algorithms (DSA), and QA Engineering. The exact emphasis depends on the specific role you apply for.
Barco 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.
- 01Barco 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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