As a Software Engineer at GSK, you play a vital role in the development and enhancement of software solutions that directly impact the company's ability to deliver innovative healthcare products. This position is crucial for ensuring that GSK's software systems are not only efficient but also capable of supporting the complex regulatory requirements inherent in the pharmaceutical industry. You will contribute to various teams responsible for applications that enhance research, streamline manufacturing processes, and improve patient outcomes. In this position, you'll find yourself working on projects that range from developing internal tools for operational efficiency to creating customer-facing applications that allow patients and healthcare providers to interact with GSK's services. The complexity of these projects demands not only technical expertise but also a strategic approach to problem-solving, making the role exciting and impactful. Expect to collaborate with cross-functional teams, including data scientists, product managers, and quality assurance specialists, to deliver solutions that align with GSK's commitment to improving health and well-being.
Behavioral Phone Screening
reportedInitial phone screening with a recruiter to evaluate behavioral fit.
What to demonstrate
- Initial phone screening with a recruiter to evaluate behavioral fit
- Depth in Python
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 phone screening above and write down what you would ask to confirm before it.
Online Technical Assessments
reportedAssessments that test coding abilities and understanding of relevant technologies.
What to demonstrate
- Assessments that test coding abilities and understanding of relevant technologies
- Depth in Python
How to prepare
- Answer aloud and timed: Can you explain how you would use Docker in a software deployment scenario?
- Answer aloud and timed: Discuss a challenging technical problem you encountered in a previous role and how you solved it.
One-on-One Interviews
reportedInterviews with hiring managers and team members to discuss background and technical skills.
What to demonstrate
- Interviews with hiring managers and team members to discuss background and technical skills
- Depth in Python
How to prepare
- Answer aloud and timed: What strategies do you use for debugging and optimizing code?
- Answer aloud and timed: Describe a time when you had to work collaboratively with a team to complete a project. What was your role?
Group Interviews
reportedInterviews that may include multiple candidates to assess collaborative problem-solving.
What to demonstrate
- Interviews that may include multiple candidates to assess collaborative problem-solving
- Depth in Python
How to prepare
- Answer aloud and timed: How do you handle constructive criticism or feedback from peers?
- Answer aloud and timed: Give an example of a situation where you had to manage conflicting priorities.
Coding Challenges
reportedChallenges that simulate real-world problem-solving scenarios.
What to demonstrate
- Challenges that simulate real-world problem-solving scenarios
- Depth in Python
How to prepare
- Answer aloud and timed: Tell me about a time when you had to learn a new technology quickly. How did you approach it?
- Answer aloud and timed: What motivates you to perform well in your role?
PracHub editorial advice for the preparation topics above.
Practice Coding
Regularly engage in coding challenges to sharpen your technical skills and problem-solving abilities.
Understand GSK's Values
Familiarize yourself with GSK’s mission and values to effectively demonstrate your alignment during interviews.
Be Ready for Behavioral Questions
Prepare specific examples from your past experiences that showcase your teamwork, adaptability, and leadership skills.
Engage with the Interviewer
Show enthusiasm and interest in the role and the company during your discussions with interviewers.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Can you solve this coding problem using Python? (You may be given a specific problem to work through.)
Can you solve this coding problem using Python? (You may be given a specific problem to work through.)
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 optimize an algorithm that is currently running in O(n^2) time complexity?
How would you optimize an algorithm that is currently running in O(n^2) time complexity?
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?
Write a function that determines if a string is a palindrome.
Write a function that determines if a string is a palindrome.
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?
Stop tag and share joins from fanning out a page
resource_tag is (resource_id, tag_id) with PK (resource_id, tag_id); resource_share is (resource_id, shared_with_user_id, permission). The tagged-and-shared listing inner-joins resource to both, filters tenant_id, tag_id = ANY($2) and shared_with_user_id = $3, orders by updated_at DESC and takes 50. Pages come back with fewer than 50 distinct resources and the total in the header is far too high. Explain the row multiplication, rewrite both the page query and the count query so each is correct, and name the index each one needs. PostgreSQL 16.
Approach
- Do the arithmetic against the predicates that are actually there. An inner join emits one row per matching child row, and both joins are filtered: tag_id = ANY($2) admits only the requested tags, shared_with_user_id = $3 admits one user's share rows. So a resource holding three of the requested tags and shared with $3 once yields three rows, not one — the multiplier is its count of matching tags times its share rows for that single user, and that second factor is 1 unless the table admits duplicate (resource_id, shared_with_user_id) pairs. LIMIT 50 then limits rows rather than resources, and COUNT(*) counts pairs — the header is the product, not the population.
- Reject DISTINCT as the fix. It deduplicates after the product has been built, so the planner must materialise and sort the fanned-out set before the LIMIT can apply, and it leaves any SUM or AVG in the same select list wrong.
- Rewrite both filters as semi-joins, keeping resource as the only row source: AND EXISTS (SELECT 1 FROM resource_tag rt WHERE rt.resource_id = r.resource_id AND rt.tag_id = ANY($2)) and the same shape against resource_share. A semi-join stops at the first match per resource and preserves the driving index order, so ORDER BY updated_at DESC, resource_id DESC LIMIT 50 still stops after 50 rows.
- Count with the same predicates and no join at all: SELECT count(*) FROM resource r WHERE r.tenant_id = $1 AND r.status = 'active' AND EXISTS (...) AND EXISTS (...). Nothing multiplies a resource, so the number is the population.
Follow-up
- The filter changes from 'any of these tags' to 'all of these tags'. Rewrite it and state what it costs relative to the ANY form.
- A resource can be shared with the same user twice under different permissions. Does your count change, and should it?
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?
What programming languages are you most proficient in, and how have you applied them in past projects?
What programming languages are you most proficient in, and how have you applied them in past 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?
Can you explain how you would use Docker in a software deployment scenario?
Can you explain how you would use Docker in a software deployment scenario?
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?
Discuss a challenging technical problem you encountered in a previous role and how you solved it.
Discuss a challenging technical problem you encountered in a previous role and how you solved it.
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?
If given a dataset with missing values, how would you handle it in your analysis?
If given a dataset with missing values, how would you handle it in your analysis?
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?
You are tasked with improving an existing application. What steps would you take to assess its current perform
You are tasked with improving an existing application. What steps would you take to assess its current performance and identify areas for improvement?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
How would you approach a situation where a project is falling behind schedule?
How would you approach a situation where a project is falling behind schedule?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
Describe a scenario where you had to analyze a complex problem and present your solution to stakeholders.
Describe a scenario where you had to analyze a complex problem and present your solution to stakeholders.
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 strategies do you use for debugging and optimizing code?
What strategies do you use for debugging and optimizing code?
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 GSK candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the GSK loop
- Write out the reported sequence: Behavioral Phone Screening, Online Technical Assessments, One-on-One Interviews, Group Interviews, Coding Challenges.
- 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 5 reported rounds, with the weakest marked.
02Work Python
- Spend the session on Python, which GSK candidates report being tested on.
- Write one worked example in Python and time yourself on it.
Deliverable: One timed worked example in Python.
03Work SQL
- Spend the session on SQL, which GSK candidates report being tested on.
- Write one worked example in SQL and time yourself on it.
Deliverable: One timed worked example in SQL.
04Work Programming/Algorithmic Problem Solving
- Spend the session on Programming/Algorithmic Problem Solving, which GSK candidates report being tested on.
- Write one worked example in Programming/Algorithmic Problem Solving and time yourself on it.
Deliverable: One timed worked example in Programming/Algorithmic Problem Solving.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: What programming languages are you most proficient in, and how have you applied them in past projects?
- Answer aloud, timed: Describe your experience with version control systems, particularly Git.
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a time when you had to work collaboratively with a team to complete a project. What was your role?
- Answer aloud, timed: How do you handle constructive criticism or feedback from peers?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
07Answer out loud: Problem-Solving / Case Studies
- Answer aloud, timed: If given a dataset with missing values, how would you handle it in your analysis?
- Answer aloud, timed: You are tasked with improving an existing application. What steps would you take to assess its current performance and identify areas for improvement?
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.
Describe your experience with version control systems, particularly Git.
Describe your experience with version control systems, particularly Git.
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 work collaboratively with a team to complete a project. What was your role?
Describe a time when you had to work collaboratively with a team to complete a project. What was your role?
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 constructive criticism or feedback from peers?
How do you handle constructive criticism or feedback from peers?
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?
Give an example of a situation where you had to manage conflicting priorities.
Give an example of a situation where you had to manage conflicting priorities.
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 when you had to learn a new technology quickly. How did you approach it?
Tell me about a time when you had to learn a new technology quickly. How did you approach 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?
What motivates you to perform well in your role?
What motivates you to perform well in your role?
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
Describe your experience with version control systems, particularly Git.
- 02
Describe a time when you had to work collaboratively with a team to complete a project. What was your role?
- 03
How do you handle constructive criticism or feedback from peers?
- 04
Give an example of a situation where you had to manage conflicting priorities.
How difficult are the interviews, and how much preparation time is typical?
The interviews are generally considered average to difficult, depending on the candidate's experience level. Candidates typically prepare for several weeks, focusing on both technical skills and understanding GSK's values.
GSK Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often demonstrate a strong technical foundation, excellent problem-solving skills, and a clear alignment with GSK's commitment to improving health.
GSK Software Engineer candidate reports ↗What is the culture and working style like at GSK?
GSK fosters a collaborative and inclusive culture that emphasizes teamwork and innovation. Employees are encouraged to share ideas and contribute to the company's mission.
GSK Software Engineer candidate reports ↗What is the typical timeline from the initial screen to the offer?
The timeline can vary, but candidates can expect the process to take anywhere from a few weeks to a couple of months, depending on the role and team.
GSK Software Engineer candidate reports ↗Are there remote work or hybrid expectations?
GSK has adopted flexible work arrangements, and candidates may have opportunities for remote or hybrid work depending on the team's needs.
GSK Software Engineer candidate reports ↗What topics does GSK test in interviews?
GSK interviews most often cover Python, Behavioral Interviewing, Time Management, Communication Skills, and Stakeholder Management. The exact emphasis depends on the specific role you apply for.
GSK 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.
- 01GSK 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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