As a Software Engineer at DEX, your role is pivotal in shaping the technology that drives our innovative products. You will be tasked with designing, developing, and maintaining software solutions that enhance user experiences and streamline internal operations. This position is essential not only for building robust systems but also for contributing to the overall strategy and vision of DEX as we aim to remain at the forefront of the industry. The impact of this role extends across various domains, from developing scalable applications to optimizing existing infrastructure. You will work on diverse projects that may involve cloud computing, data analytics, and machine learning, collaborating with cross-functional teams to ensure that our solutions are both effective and aligned with the company’s objectives. As a Software Engineer, you will have the opportunity to tackle complex challenges and influence the direction of our products, making your contributions both meaningful and rewarding. In this dynamic environment, you can expect to engage with cutting-edge technologies and methodologies, fostering continuous learning and professional growth. The role is designed for individuals who are not only technically proficient but also passionate about creating impactful software that resonates with our users.
Initial Screening
reportedThe process begins with an initial screening to evaluate your basic qualifications and fit.
What to demonstrate
- The process begins with an initial screening to evaluate your basic qualifications and fit
- Depth in Analog Circuit Analysis
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 Assessments
reportedCandidates undergo technical assessments to evaluate their technical skills and problem-solving abilities.
What to demonstrate
- Candidates undergo technical assessments to evaluate their technical skills and problem-solving abilities
- Depth in Analog Circuit Analysis
How to prepare
- Answer aloud and timed: Describe how RESTful APIs work and their importance.
- Answer aloud and timed: Can you discuss a time when you optimized an application for performance?
Behavioral Interviews
reportedFinal stage involves behavioral interviews to assess cultural fit and interpersonal competencies.
What to demonstrate
- Final stage involves behavioral interviews to assess cultural fit and interpersonal competencies
- Depth in Analog Circuit Analysis
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 interviews above and write down what you would ask to confirm before it.
PracHub editorial advice for the preparation topics above.
Practice Coding
Regularly engage in coding challenges to sharpen your skills and improve your problem-solving abilities.
Understand Company Values
Familiarize yourself with DEX’s mission and values to effectively communicate how you align with the company culture.
Mock Interviews
Conduct mock interviews with peers or mentors to build confidence and receive constructive feedback.
Engage with the Community
Participate in relevant forums and discussions on platforms like Reddit or online interview communities to gain insights from other candidates’ experiences.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Write a function that reverses a string.
Write a function that reverses a string.
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 the time complexity of your solution.
Explain the time complexity of your solution.
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 an algorithm to sort a list of numbers?
How would you implement an algorithm to sort a list of numbers?
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 involving data structures, such as linked lists or trees.
Solve a problem involving data structures, such as linked lists or trees.
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 you would approach a coding challenge on a platform like LeetCode.
Explain how you would approach a coding challenge on a platform like LeetCode.
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 are the differences between SQL and NoSQL databases?
What are the differences between SQL and NoSQL databases?
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?
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?
Explain the difference between analog and digital circuits.
Explain the difference between analog and digital circuits.
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 are the key principles of object-oriented programming?
What are the key 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?
Describe how RESTful APIs work and their importance.
Describe how RESTful APIs work and their importance.
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 hypothetical scenario, outline your approach to developing a new feature.
Given a hypothetical scenario, outline your approach to developing a new feature.
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 how you would scale an application to handle increased user traffic.
Describe how you would scale an application to handle increased user traffic.
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 technical challenge you faced and how you resolved it.
Discuss a technical challenge you faced and how you resolved 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?
How would you troubleshoot a system that is running slowly?
How would you troubleshoot a system that is running slowly?
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?
How do you approach debugging a piece of software?
How do you approach debugging a piece of software?
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 DEX candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the DEX loop
- Write out the reported sequence: Initial Screening, Technical Assessments, Behavioral 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 Analog Circuit Analysis
- Spend the session on Analog Circuit Analysis, which DEX candidates report being tested on.
- Write one worked example in Analog Circuit Analysis and time yourself on it.
Deliverable: One timed worked example in Analog Circuit Analysis.
03Work Digital Circuit Analysis
- Spend the session on Digital Circuit Analysis, which DEX candidates report being tested on.
- Write one worked example in Digital Circuit Analysis and time yourself on it.
Deliverable: One timed worked example in Digital Circuit Analysis.
04Work Basic Electronics Laws
- Spend the session on Basic Electronics Laws, which DEX candidates report being tested on.
- Write one worked example in Basic Electronics Laws and time yourself on it.
Deliverable: One timed worked example in Basic Electronics Laws.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: Explain the difference between analog and digital circuits.
- Answer aloud, timed: What are the key principles of object-oriented programming?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Behavioral / Leadership Questions
- Answer aloud, timed: Describe a challenging project you worked on. How did you handle it?
- Answer aloud, timed: How do you prioritize tasks when working on multiple projects?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership Questions question(s), under time.
07Answer out loud: Problem-solving / Case Studies
- Answer aloud, timed: How would you troubleshoot a system that is running slowly?
- Answer aloud, timed: Given a hypothetical scenario, outline your approach to developing a new feature.
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.
Can you discuss a time when you optimized an application for performance?
Can you discuss a time when you optimized an application for performance?
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 challenging project you worked on. How did you handle it?
Describe a challenging project you worked on. 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 working on multiple projects?
How do you prioritize tasks when working on 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?
Tell me about a time you worked in a team. What was your role, and how did you contribute?
Tell me about a time you worked in a team. What was your role, and how did you contribute?
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 disagreements with team members?
How do you handle disagreements with team members?
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 do your best work?
What motivates you to do 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?
- 01
Can you discuss a time when you optimized an application for performance?
- 02
Describe a challenging project you worked on. How did you handle it?
- 03
How do you prioritize tasks when working on multiple projects?
- 04
Tell me about a time you worked in a team. What was your role, and how did you contribute?
What is the interview difficulty and how much preparation time is typical?
The interview process can vary in difficulty, but candidates should prepare for a mix of technical and behavioral questions. A preparation time of 2-4 weeks is recommended to brush up on relevant skills and engage in mock interviews.
DEX Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often demonstrate a deep understanding of software engineering principles, strong problem-solving skills, and the ability to communicate effectively with team members.
DEX Software Engineer candidate reports ↗What is the culture and working style at DEX?
DEX promotes a collaborative and innovative culture, emphasizing teamwork and open communication. Employees are encouraged to share ideas and contribute to the continuous improvement of processes.
DEX Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The timeline may vary, but candidates can expect the process to take 3-6 weeks from initial screening to receiving an offer.
DEX Software Engineer candidate reports ↗Are there remote work or hybrid expectations?
DEX supports flexible work arrangements, including remote and hybrid options, depending on team needs and individual preferences.
DEX Software Engineer candidate reports ↗What topics does DEX test in interviews?
DEX interviews most often cover Analog electronics fundamentals, Account Executive role fundamentals, Analog Circuit Analysis, Digital electronics fundamentals, and Digital Circuit Analysis. The exact emphasis depends on the specific role you apply for.
DEX 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.
- 01DEX 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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