The role of a Software Engineer at North Highland is pivotal in driving innovative technology solutions that meet complex client needs. As a Software Engineer, you will engage in the design, development, and implementation of software applications that enhance user experiences and streamline operations. Your work directly impacts the effectiveness of North Highland's offerings, influencing everything from internal processes to customer-facing products. This position is critical as it not only involves coding but also encompasses problem-solving, collaboration with cross-functional teams, and a deep understanding of business processes. You will work on exciting projects that may include developing scalable applications, integrating systems, or optimizing existing platforms. The dynamic environment at North Highland allows for both personal and professional growth, challenging you to push boundaries and innovate in the tech space.
Phone Screen
reportedInitial phone screen with a recruiter to assess background and fit for the role.
What to demonstrate
- Initial phone screen with a recruiter to assess background and fit for the role
- Depth in Database Querying / SQL
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 Phone Interview
reportedA technical phone interview to evaluate your technical capabilities.
What to demonstrate
- A technical phone interview to evaluate your technical capabilities
- Depth in Database Querying / SQL
How to prepare
- Answer aloud and timed: What programming languages are you most proficient in, and why?
- Answer aloud and timed: Explain the concept of RESTful APIs and provide an example of their use.
On-site Interviews
reportedA full day of on-site interviews with team members and management to assess collaboration and communication.
What to demonstrate
- A full day of on-site interviews with team members and management to assess collaboration and communication
- Depth in Database Querying / SQL
How to prepare
- Answer aloud and timed: Discuss your experience with cloud technologies, such as AWS or Azure.
- Answer aloud and timed: Can you give an example of a time you faced a conflict in a team setting? How did you resolve it?
PracHub editorial advice for the preparation topics above.
Research the company
Understanding North Highland’s mission and values will help you articulate how you align with them during your interview.
Practice coding challenges
Familiarize yourself with common coding problems and practice your solutions to demonstrate your technical proficiency.
Prepare examples
Be ready to discuss specific projects or experiences that highlight your skills and contributions.
Engage in mock interviews
Conduct practice interviews with peers to build confidence and improve your communication skills.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Write a function to reverse a linked list.
Write a function to reverse a linked list.
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?
How would you implement a binary search algorithm?
How would you implement a binary search algorithm?
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?
Given a set of integers, find all unique triplets that sum to zero.
Given a set of integers, find all unique triplets that sum to zero.
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 time complexity and provide an example of O(n log n).
Explain time complexity and provide an example of O(n log n).
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?
Keep soft-deleted accounts from blocking re-registration
app_user holds user_id, tenant_id, email CITEXT, password_hash (NULL for SSO principals), email_verified_at, auth_version, status ('invited','active','suspended','deactivated'), created_at, updated_at, deleted_at. Two live accounts for one address inside a tenant must be impossible, but an address freed by a soft delete must be reusable, and the same tenant may delete and re-register it repeatedly. Write the uniqueness DDL for PostgreSQL 16, then the equivalent for MySQL 8 where partial indexes do not exist, and say what each permits once three deleted rows already hold that address.
Approach
- Start from what is actually unique: not (tenant_id, email), but (tenant_id, email) among live rows. PostgreSQL says that directly — CREATE UNIQUE INDEX app_user_live_email ON app_user (tenant_id, email) WHERE deleted_at IS NULL. A full constraint over the same two columns burns the address permanently the first time someone deletes an account.
- Keep case-insensitivity in the type or the index, never in the application: CITEXT as given, or UNIQUE (tenant_id, lower(email)) as an expression index where the extension is unavailable. A case-sensitive unique column is exactly how two accounts for one human appear.
- For MySQL 8 the predicate has to move inside the key: add a discriminator column that is a constant 0 while the row is live and is set to user_id on delete, with UNIQUE (tenant_id, email, deleted_marker). Live rows share the constant and still collide; deleted rows differ from each other and stop colliding.
- State the NULL variant and its dependency: leaving the marker NULL for deleted rows also works, because a unique index treats NULLs as distinct — true in MySQL, and true in PostgreSQL only under the default NULLS DISTINCT, which PostgreSQL 15 lets you reverse. Check the polarity against the three existing deleted rows: constant-on-live is what preserves the collision you want, and reversing it silently admits duplicate live accounts.
Follow-up
- A deleted account re-registers with the same address the next day. Do the old resource rows follow the new user_id, and how does the API keep the two principals apart?
- How do you honour an erasure request while resource_revision.actor_user_id still references this table?
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?
Describe a challenging technical problem you solved.
Describe a challenging technical problem you solved.
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 programming languages are you most proficient in, and why?
What programming languages are you most proficient in, and why?
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?
Explain the concept of RESTful APIs and provide an example of their use.
Explain the concept of RESTful APIs and provide an example of their use.
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 design a system for an online bookstore?
How would you design a system for an online bookstore?
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?
Given a dataset, how would you identify trends and insights?
Given a dataset, how would you identify trends and insights?
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 steps would you take to optimize a slow-running application?
What steps would you take to optimize a slow-running application?
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 messaging service for a mobile application?
How would you architect a messaging service for a mobile application?
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?
Discuss the trade-offs between microservices and monolithic architectures.
Discuss the trade-offs between microservices and monolithic architectures.
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 ensure data integrity and security in your applications?
How would you ensure data integrity and security in your applications?
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 how you would scale a web application to handle millions of users.
Describe how you would scale a web application to handle millions of users.
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 approach debugging an application?
How do you approach debugging an application?
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 North Highland candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the North Highland loop
- Write out the reported sequence: Phone Screen, Technical Phone Interview, On-site 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 Database Querying / SQL
- Spend the session on Database Querying / SQL, which North Highland candidates report being tested on.
- Write one worked example in Database Querying / SQL and time yourself on it.
Deliverable: One timed worked example in Database Querying / SQL.
03Work Technical Phone Screen
- Spend the session on Technical Phone Screen, which North Highland candidates report being tested on.
- Write one worked example in Technical Phone Screen and time yourself on it.
Deliverable: One timed worked example in Technical Phone Screen.
04Work Recruiter/HR Phone Screen
- Spend the session on Recruiter/HR Phone Screen, which North Highland candidates report being tested on.
- Write one worked example in Recruiter/HR Phone Screen and time yourself on it.
Deliverable: One timed worked example in Recruiter/HR Phone Screen.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: Describe a challenging technical problem you solved.
- Answer aloud, timed: How do you approach debugging an application?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Can you give an example of a time you faced a conflict in a team setting? How did you resolve it?
- Answer aloud, timed: How do you prioritize your work when facing multiple deadlines?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
07Answer out loud: Problem-Solving / Case Studies
- Answer aloud, timed: How would you design a system for an online bookstore?
- Answer aloud, timed: Given a dataset, how would you identify trends and insights?
Deliverable: Spoken answers to 2 reported Problem-Solving / Case Studies 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.
Discuss your experience with cloud technologies, such as AWS or Azure.
Discuss your experience with cloud technologies, such as AWS or Azure.
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?
Can you give an example of a time you faced a conflict in a team setting? How did you resolve it?
Can you give an example of a time you faced a conflict in a team setting? How did you resolve 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?
How do you prioritize your work when facing multiple deadlines?
How do you prioritize your work when facing multiple deadlines?
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 time when you had to adapt quickly to changes in project scope.
Describe a time when you had to adapt quickly to changes in project scope.
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 motivates you to perform your best work?
What motivates you to perform your best work?
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 ensure effective communication with non-technical stakeholders?
How do you ensure effective communication with non-technical stakeholders?
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 time when you had to make a decision with limited information.
Describe a time when you had to make a decision with limited information.
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
Discuss your experience with cloud technologies, such as AWS or Azure.
- 02
Can you give an example of a time you faced a conflict in a team setting? How did you resolve it?
- 03
How do you prioritize your work when facing multiple deadlines?
- 04
Describe a time when you had to adapt quickly to changes in project scope.
What is the typical interview difficulty for this role?
The interview process is generally considered average in difficulty, focusing on both technical skills and cultural fit. Candidates should prepare thoroughly to demonstrate their capabilities.
North Highland Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates are those who not only possess strong technical skills but also align well with the company's culture and values. Effective communication and problem-solving abilities are equally important.
North Highland Software Engineer candidate reports ↗What is the culture like at North Highland?
North Highland fosters a collaborative and innovative environment where team members are encouraged to share ideas and support one another. The company values integrity, respect, and a commitment to excellence.
North Highland Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The process can vary, but candidates often receive feedback within a few weeks after completing the final interview. Prompt communication is a priority for North Highland.
North Highland Software Engineer candidate reports ↗Are there remote work options?
North Highland offers hybrid work arrangements, allowing for flexibility in work locations while still maintaining a strong team culture.
North Highland Software Engineer candidate reports ↗What topics does North Highland test in interviews?
North Highland interviews most often cover Analytical Problem Solving, Data Modeling, Time Management, Stakeholder Coordination, and Requirements Gathering. The exact emphasis depends on the specific role you apply for.
North Highland 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.
- 01North Highland 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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