The role of a Software Engineer at Diligent Tec is pivotal to the company's mission of delivering high-quality, innovative technology solutions to its clients. As a Software Engineer, you will be responsible for designing, developing, and maintaining complex software systems that enhance the functionality and efficiency of Diligent Tec's products. This role is essential not only for technical execution but also for influencing product direction and user experience, making it a critical position within the organization. You will directly impact various teams and projects, contributing to products that serve a diverse range of clients across multiple sectors. From enhancing API functionalities to optimizing data infrastructures, your work will shape how users interact with technology. Expect to tackle challenges that require both creativity and analytical thinking, as you'll be involved in projects that demand high scalability and performance. This position is an excellent opportunity for candidates eager to work on complex systems and make a tangible difference in the technology landscape.
Initial Phone Screen
reportedFirst stage to assess candidate's background and fit for the role.
What to demonstrate
- First stage to assess candidate's background and fit for the role
- Depth in AWS (Amazon Web Services)
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
reportedIncludes coding assessments, system design discussions, and behavioral interviews.
What to demonstrate
- Includes coding assessments, system design discussions, and behavioral interviews
- Depth in AWS (Amazon Web Services)
How to prepare
- Answer aloud and timed: How do you ensure the security of an API?
- Answer aloud and timed: Explain the concept of microservices and its advantages.
Final Discussions
reportedConcludes the interview process with discussions about the role and candidate fit.
What to demonstrate
- Concludes the interview process with discussions about the role and candidate fit
- Depth in AWS (Amazon Web Services)
How to prepare
- Answer aloud and timed: What are common performance bottlenecks in software applications?
- Answer aloud and timed: Design a URL shortening service. What components would you include?
PracHub editorial advice for the preparation topics above.
Understand the Company’s Values
Familiarize yourself with Diligent Tec’s mission and values, and be prepared to discuss how you embody them in your work.
Practice Coding
Use platforms like LeetCode or HackerRank to sharpen your coding skills, as technical interviews often include live coding sessions.
Be Ready to Collaborate
Emphasize your ability to work in teams and engage in discussions about technology and solutions.
Prepare Questions
Have thoughtful questions ready for your interviewers that demonstrate your interest in the role and the company culture.
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 string. Discuss its complexity.
Write a function to reverse a string. Discuss its 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?
How would you implement a search algorithm for a sorted array?
How would you implement a search algorithm for a sorted array?
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 problem using dynamic programming and explain your reasoning.
Solve a problem using dynamic programming and explain your reasoning.
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?
What data structure would you use to implement a LRU cache?
What data structure would you use to implement a LRU cache?
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?
Can you write a code snippet for merging two sorted linked lists?
Can you write a code snippet for merging two sorted linked lists?
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?
What factors do you consider when designing a database schema?
What factors do you consider when designing a database schema?
Approach
- Name the grain you start from and join outward from it.
- Check whether any join is one-to-many before aggregating, or the sums inflate.
- Say which index the query would use, and what makes it unusable.
- Handle the rows that do not match: that is usually the actual question.
Follow-up
- How does the query change if that join becomes one-to-many?
- What happens to this when the table is ten times larger?
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 the differences between REST and SOAP API architectures.
Describe the differences between REST and SOAP API architectures.
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?
What are the principles of object-oriented programming?
What are the principles of object-oriented programming?
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 ensure the security of an API?
How do you ensure the security of an API?
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 concept of microservices and its advantages.
Explain the concept of microservices and its advantages.
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 are common performance bottlenecks in software applications?
What are common performance bottlenecks in software applications?
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 URL shortening service. What components would you include?
Design a URL shortening service. What components would you include?
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 structure a data storage solution for a high-traffic web application?
How would you structure a data storage solution for a high-traffic web 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 how you would handle user authentication in a distributed system.
Discuss how you would handle user authentication in a distributed system.
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?
Explain how you would approach load balancing in a cloud environment.
Explain how you would approach load balancing in a cloud environment.
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 have a performance issue in a web application. How would you diagnose it?
You have a performance issue in a web application. How would you diagnose 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?
Given a dataset, how would you analyze it to extract meaningful insights?
Given a dataset, how would you analyze it to extract meaningful 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 an existing piece of code?
What steps would you take to optimize an existing piece of code?
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 given a new feature request. How would you assess its impact on the current system?
You are given a new feature request. How would you assess its impact on the current system?
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 debugging a critical issue in a production environment?
How would you approach debugging a critical issue in a production environment?
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 Diligent Tec candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Diligent Tec loop
- Write out the reported sequence: Initial Phone Screen, Technical Interviews, Final Discussions.
- 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 AWS (Amazon Web Services)
- Spend the session on AWS (Amazon Web Services), which Diligent Tec candidates report being tested on.
- Write one worked example in AWS (Amazon Web Services) and time yourself on it.
Deliverable: One timed worked example in AWS (Amazon Web Services).
03Work Cloud Architecture
- Spend the session on Cloud Architecture, which Diligent Tec candidates report being tested on.
- Write one worked example in Cloud Architecture and time yourself on it.
Deliverable: One timed worked example in Cloud Architecture.
04Work Data Infrastructure
- Spend the session on Data Infrastructure, which Diligent Tec candidates report being tested on.
- Write one worked example in Data Infrastructure and time yourself on it.
Deliverable: One timed worked example in Data Infrastructure.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: Describe the differences between REST and SOAP API architectures.
- Answer aloud, timed: What are the principles of object-oriented programming?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: System Design / Architecture
- Answer aloud, timed: Design a URL shortening service. What components would you include?
- Answer aloud, timed: How would you structure a data storage solution for a high-traffic web 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 challenge in a project. How did you handle it?
- Answer aloud, timed: How do you prioritize tasks when managing multiple projects?
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.
Describe a time when you faced a significant challenge in a project. How did you handle it?
Describe a time when you faced a significant challenge in a project. How did you handle 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 tasks when managing multiple projects?
How do you prioritize tasks when managing multiple 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 contributed to a team’s success?
Can you give an example of how you contributed to a team’s success?
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 do you do to ensure effective communication within a team?
What do you do to ensure effective communication within a 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?
Describe a situation where you had to resolve a conflict with a coworker.
Describe a situation where you had to resolve a conflict with a coworker.
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 a time when you faced a significant challenge in a project. How did you handle it?
- 02
How do you prioritize tasks when managing multiple projects?
- 03
Can you give an example of how you contributed to a team’s success?
- 04
What do you do to ensure effective communication within a team?
How difficult is the interview process, and how much preparation time should I expect?
The interview process at Diligent Tec is thorough and challenging, requiring significant preparation. Candidates typically spend several weeks preparing, focusing on both technical skills and behavioral aspects.
Diligent Tec Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often demonstrate a strong understanding of technical concepts, effective problem-solving skills, and a collaborative mindset. They also align well with the company’s values and culture.
Diligent Tec Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The entire process can take anywhere from 4 to 6 weeks, depending on the scheduling of interviews and the number of candidates being considered.
Diligent Tec Software Engineer candidate reports ↗What is the culture and working style like at Diligent Tec?
Diligent Tec fosters a collaborative environment that values innovation and teamwork. Engineers are encouraged to share ideas and participate in decision-making processes.
Diligent Tec Software Engineer candidate reports ↗Are there opportunities for remote work or flexible arrangements?
Yes, Diligent Tec offers flexible working arrangements, including remote work options depending on the team's needs and project requirements.
Diligent Tec Software Engineer candidate reports ↗What is the interview process loop for Diligent Tec Software Engineer, and what happens in each stage?
Diligent Tec’s Software Engineer process starts with an initial phone screen to assess background and fit. Next comes technical interviews that include coding assessments, system design discussions, and behavioral interviews. The loop ends with final discussions focused on role and candidate fit.
Diligent Tec Software Engineer candidate reports ↗How hard is the Diligent Tec Software Engineer interview compared to other roles, and what should I prepare for?
Candidates report Diligent Tec interviews as more difficult than average, with the highest impact coming from technical and system-level evaluation. For preparation, prioritize coding plus system design and architecture topics that connect to cloud and infrastructure, because those appear most often in the role’s tested focus.
Diligent Tec Software Engineer candidate reports ↗What technical topics does Diligent Tec test for Software Engineer interviews?
Expect emphasis on AWS and cloud architecture, plus data infrastructure and solution or infrastructure architecture. API design, data engineering, and tooling engineering also show up among the top topics, so be ready to discuss both implementation and design choices.
Diligent Tec Software Engineer candidate reports ↗What coding and public sample questions should I expect for Diligent Tec Software Engineer?
Public sample questions include “Merge Two Sorted Linked Lists” and a performance-focused problem: “Owning a Critical Performance Bottleneck.” If you practice, also make sure you can explain time and space complexity and discuss how you would identify and fix performance issues during execution.
Diligent Tec Software Engineer candidate reports ↗How many questions are in the Diligent Tec Software Engineer interview question set, and what should that imply for my prep?
The question bank size is 25, so the interview is likely to draw from a relatively bounded set of patterns rather than entirely random topics. Focus your prep on the repeated themes, especially the listed cloud, API, data infrastructure, and architecture areas, and on the coding and performance discussion patterns shown in the public samples.
Diligent Tec 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.
- 01Diligent Tec 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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