As a Software Engineer at TOPSYS IT, you play a pivotal role in delivering innovative technology solutions that directly impact our clients, products, and overall business success. This position is critical not just for the technical skills you bring, but also for your ability to collaborate across various teams to solve complex problems. The work you do affects millions of users and contributes to the ongoing development of our cutting-edge products, such as enterprise software solutions and integration platforms. In a fast-paced environment that emphasizes agility and quality, you will engage with dynamic teams focused on creating scalable software that meets high standards. The complexity of our projects, combined with the strategic influence of your contributions, makes this role both challenging and rewarding. You will not only refine your technical expertise but also enhance your capability to drive significant business outcomes.
Initial Screening
reportedThe first step involves a review of the candidate's application and background.
What to demonstrate
- The first step involves a review of the candidate's application and background
- Depth in .NET
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 Interviews
reportedCandidates undergo multiple technical interviews assessing their coding skills and system design abilities.
What to demonstrate
- Candidates undergo multiple technical interviews assessing their coding skills and system design abilities
- Depth in .NET
How to prepare
- Answer aloud and timed: Explain the differences between Agile and Waterfall methodologies.
- Answer aloud and timed: How do you approach debugging a complex software issue?
Behavioral Assessments
reportedInterviews focus on past experiences and cultural fit within the company.
What to demonstrate
- Interviews focus on past experiences and cultural fit within the company
- Depth in .NET
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 assessments above and write down what you would ask to confirm before it.
Final Interviews
reportedCandidates may engage with various team members, including technical leads and HR representatives.
What to demonstrate
- Candidates may engage with various team members
- Including technical leads and HR representatives
How to prepare
- Answer aloud and timed: What factors do you consider when choosing a database for a new application?
- Answer aloud and timed: Describe a situation where you had to refactor a significant portion of your codebase. What were the challenges, and how did you approach them?
PracHub editorial advice for the preparation topics above.
Prepare for coding challenges
Practice coding problems regularly, focusing on algorithms and data structures to enhance your problem-solving skills.
Showcase your projects
Be ready to discuss your past projects in detail, emphasizing your contributions and the impact on the team or organization.
Align with company values
Familiarize yourself with TOPSYS IT's core values and be prepared to discuss how you embody these in your work.
Ask insightful questions
Prepare thoughtful questions for your interviewers to demonstrate your interest in the role and the company.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
How would you approach a project with ambiguous requirements?
How would you approach a project with ambiguous requirements?
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 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?
Given an array of integers, find two numbers that add up to a specific target.
Given an array of integers, find two numbers that add up to a specific target.
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 how hash tables work and provide an example of their usage.
Explain how hash tables work and provide an example of their usage.
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?
Solve a binary tree traversal problem (e.g., in-order, pre-order).
Solve a binary tree traversal problem (e.g., in-order, pre-order).
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?
Discuss time and space complexity in the context of your solutions.
Discuss time and space complexity in the context of your solutions.
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?
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?
Explain why the owner filter ignores the listing index
The only index on resource is (tenant_id, status, updated_at DESC, resource_id DESC). A new endpoint returns one user's resources across all statuses, newest created first: WHERE tenant_id = $1 AND owner_user_id = $2 ORDER BY created_at DESC LIMIT 20. On a tenant with 2M rows it takes 900 ms and EXPLAIN shows a sort above a large scan. Explain precisely why the existing index cannot serve it, give the index that can, and state which of these the new index still will not help: owner_user_id alone across tenants; the same query ordered by updated_at. PostgreSQL 16.
Approach
- Separate the two jobs an index does. For filtering, a composite btree is seekable only on a left prefix, so with no predicate on status the scan can at best range over tenant_id and test owner_user_id per row; PostgreSQL 16 has no btree skip scan to jump the unconstrained column.
- For ordering, the index is sorted by (status, updated_at) within a tenant and not by created_at, so the LIMIT cannot stop early: every matching row is read and then sorted. That is the 'Sort Method: top-N heapsort' line, and it is why the plan reads 2M rows to answer with 20.
- Derive the replacement from the access path — equality, equality, then the ordering column: CREATE INDEX CONCURRENTLY ON resource (tenant_id, owner_user_id, created_at DESC). The scan seeks to the (tenant, owner) range and walks 20 entries in order, so the Sort node disappears along with the row-read.
- Treat INCLUDE (title, status) as conditional, not free. An index-only scan still visits the heap for any row whose page is not marked all-visible, so on a table taking 1.2k writes/second the win depends on autovacuum keeping the visibility map current, and the wider index costs more on every insert.
Follow-up
- 90% of rows are status='active'. Would a partial index WHERE status = 'active' change your answer, and for which of the three queries?
- A dashboard runs this for 40 owners in one page load. What changes about the design?
Describe the principles of RESTful API design.
Describe the principles of RESTful API design.
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?
Explain the differences between Agile and Waterfall methodologies.
Explain the differences between Agile and Waterfall methodologies.
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 walk us through a recent project where you utilized.NET technologies?
Can you walk us through a recent project where you utilized.NET technologies?
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 to handle millions of transactions per day?
How would you design a system to handle millions of transactions per day?
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?
What factors do you consider when choosing a database for a new application?
What factors do you consider when choosing a database for a new 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?
Describe a situation where you had to refactor a significant portion of your codebase. What were the challenge
Describe a situation where you had to refactor a significant portion of your codebase. What were the challenges, and how did you approach them?
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?
Can you explain the microservices architecture and its benefits over a monolithic structure?
Can you explain the microservices architecture and its benefits over a monolithic structure?
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 ensure high availability and fault tolerance in your applications?
How do you ensure high availability and fault tolerance 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?
You are given a performance issue in a production system. How would you diagnose and resolve it?
You are given a performance issue in a production system. How would you diagnose and resolve 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?
Imagine you need to implement a new feature within a tight deadline. What steps would you take to ensure its s
Imagine you need to implement a new feature within a tight deadline. What steps would you take to ensure its success?
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?
Analyze this code snippet and identify potential bugs or areas for improvement.
Analyze this code snippet and identify potential bugs or 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?
If tasked with optimizing an existing application, what metrics would you consider?
If tasked with optimizing an existing application, what metrics would you consider?
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 approach debugging a complex software issue?
How do you approach debugging a complex software issue?
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 TOPSYS IT candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the TOPSYS IT loop
- Write out the reported sequence: Initial Screening, Technical Interviews, Behavioral Assessments, Final 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 4 reported rounds, with the weakest marked.
02Work .NET
- Spend the session on .NET, which TOPSYS IT candidates report being tested on.
- Write one worked example in .NET and time yourself on it.
Deliverable: One timed worked example in .NET.
03Work Software Engineering
- Spend the session on Software Engineering, which TOPSYS IT candidates report being tested on.
- Write one worked example in Software Engineering and time yourself on it.
Deliverable: One timed worked example in Software Engineering.
04Work Software Development
- Spend the session on Software Development, which TOPSYS IT candidates report being tested on.
- Write one worked example in Software Development and time yourself on it.
Deliverable: One timed worked example in Software Development.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: What is your experience with Mulesoft, and can you explain how it integrates with other systems?
- Answer aloud, timed: Describe the principles of RESTful API design.
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: System Design / Architecture
- Answer aloud, timed: How would you design a system to handle millions of transactions per day?
- Answer aloud, timed: What factors do you consider when choosing a database for a new application?
Deliverable: Spoken answers to 2 reported System Design / Architecture question(s), under time.
07Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a time when you faced a significant technical challenge. How did you overcome it?
- Answer aloud, timed: How do you handle conflicts within your team?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership 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.
What is your experience with Mulesoft, and can you explain how it integrates with other systems?
What is your experience with Mulesoft, and can you explain how it integrates with other systems?
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 faced a significant technical challenge. How did you overcome it?
Describe a time when you faced a significant technical challenge. How did you overcome it?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
How do you handle conflicts within your team?
How do you handle conflicts within your team?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
What role do you typically take in team projects?
What role do you typically take in team projects?
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 how you mentored a colleague?
Can you give an example of how you mentored a colleague?
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?
Discuss a time when you received constructive criticism. How did you respond?
Discuss a time when you received constructive criticism. How did you respond?
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
What is your experience with Mulesoft, and can you explain how it integrates with other systems?
- 02
Describe a time when you faced a significant technical challenge. How did you overcome it?
- 03
How do you handle conflicts within your team?
- 04
What role do you typically take in team projects?
How difficult is the interview process at TOPSYS IT?
The interview process is rigorous and designed to assess both technical and soft skills. Candidates typically find it challenging, but thorough preparation can significantly enhance your confidence and performance.
TOPSYS IT Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often demonstrate a strong combination of technical expertise, effective communication, and a collaborative spirit. They also show a proactive approach to problem-solving and a willingness to learn.
TOPSYS IT Software Engineer candidate reports ↗What is the company culture like at TOPSYS IT?
The culture is collaborative, innovative, and values continuous learning. Employees are encouraged to share ideas and drive change, making it a dynamic environment to work in.
TOPSYS IT Software Engineer candidate reports ↗How long does the interview process usually take?
From the initial screening to the final offer, the process typically takes 4-6 weeks, depending on the availability of interviewers and candidates.
TOPSYS IT Software Engineer candidate reports ↗Are there remote work options available?
TOPSYS IT offers a hybrid model, allowing flexibility in work arrangements. However, specific policies may depend on team requirements and project needs.
TOPSYS IT Software Engineer candidate reports ↗What topics does TOPSYS IT test in interviews?
TOPSYS IT interviews most often cover.NET, Software Engineering, Software Development, MuleSoft, and Programming Languages (C#/.NET ecosystem). The exact emphasis depends on the specific role you apply for.
TOPSYS IT 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.
- 01TOPSYS IT 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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