As a Software Engineer at Oncor Electric Delivery, you will play a pivotal role in the development and maintenance of software systems that support the delivery of electricity to millions of customers. Your contributions will directly impact the efficiency, reliability, and safety of energy distribution, making this role essential in a company that prioritizes innovation and sustainability in the energy sector. You will work on critical projects that involve real-time data analytics, system automation, and operational technology, ensuring that Oncor remains at the forefront of the utility industry. This position is not only about coding; it encompasses problem-solving and collaboration across various teams. You will engage with cross-functional teams to understand user requirements, design scalable solutions, and implement software solutions that enhance operational capabilities. Given the complexity and scale of Oncor's operations, your work will influence strategic decisions and drive improvements in customer service, operational efficiency, and regulatory compliance. Candidates can expect a challenging yet rewarding environment where your technical skills will be honed and your contributions recognized. You will have the opportunity to work on projects that are not only technically sophisticated but also socially impactful, contributing to a cleaner and more sustainable future.
Initial Screening
reportedConducted at a career fair or university recruitment event to assess candidate interest.
What to demonstrate
- Conducted at a career fair or university recruitment event to assess candidate interest
- Depth in Behavioral Interviewing
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.
On-Campus Interview
reportedMeet with engineers and managers to evaluate fit for the role.
What to demonstrate
- Meet with engineers and managers to evaluate fit for the role
- Depth in Behavioral Interviewing
How to prepare
- Answer aloud and timed: Explain a time when you had to adapt to significant changes at work.
- Answer aloud and timed: What programming languages are you most comfortable with, and why?
Onsite Interview
reportedMultiple sessions with different team members to interact and learn about projects.
What to demonstrate
- Multiple sessions with different team members to interact and learn about projects
- Depth in Behavioral Interviewing
How to prepare
- Answer aloud and timed: Can you explain the software development lifecycle you follow?
- Answer aloud and timed: Discuss any experience you have with data analytics or energy management systems.
PracHub editorial advice for the preparation topics above.
Prepare to Share Your Story
Be ready to discuss your experiences and how they relate to the role. This personal narrative helps interviewers connect with you.
Emphasize Teamwork
Oncor values collaboration, so highlight instances where you've successfully worked in a team environment.
Practice STAR Responses
Use the STAR (Situation, Task, Action, Result) method for structuring your answers to behavioral questions. This format helps convey your experiences clearly and effectively.
Show Enthusiasm for Sustainability
Given Oncor's commitment to sustainable energy solutions, expressing your passion for environmental issues can resonate positively with your interviewers.
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 in your preferred programming language.
Write a function to reverse a string in your preferred programming language.
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 a search algorithm?
How would you optimize a search algorithm?
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Explain the difference between a stack and a queue.
Explain the difference between a stack and a queue.
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?
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?
What programming languages are you most comfortable with, and why?
What programming languages are you most comfortable with, and why?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
Can you explain the software development lifecycle you follow?
Can you explain the software development lifecycle you follow?
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 any experience you have with data analytics or energy management systems.
Discuss any experience you have with data analytics or energy management systems.
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 you were tasked with improving system efficiency, where would you start?
If you were tasked with improving system efficiency, where would you start?
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 prioritize multiple projects with competing deadlines?
How would you prioritize multiple projects with competing deadlines?
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 approach debugging a complex software issue.
Describe how you would 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 Oncor Electric Delivery candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Oncor Electric Delivery loop
- Write out the reported sequence: Initial Screening, On-Campus Interview, Onsite Interview.
- 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 Behavioral Interviewing
- Spend the session on Behavioral Interviewing, which Oncor Electric Delivery candidates report being tested on.
- Write one worked example in Behavioral Interviewing and time yourself on it.
Deliverable: One timed worked example in Behavioral Interviewing.
03Work Leadership & Leadership Qualities
- Spend the session on Leadership & Leadership Qualities, which Oncor Electric Delivery candidates report being tested on.
- Write one worked example in Leadership & Leadership Qualities and time yourself on it.
Deliverable: One timed worked example in Leadership & Leadership Qualities.
04Work STAR Method (Situation-Task-Action-Result)
- Spend the session on STAR Method (Situation-Task-Action-Result), which Oncor Electric Delivery candidates report being tested on.
- Write one worked example in STAR Method (Situation-Task-Action-Result) and time yourself on it.
Deliverable: One timed worked example in STAR Method (Situation-Task-Action-Result).
05Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a time when you faced a conflict while working on a team. How did you handle it?
- Answer aloud, timed: Tell me about a situation where you demonstrated leadership in a project.
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
06Answer out loud: Technical / Domain Knowledge
- Answer aloud, timed: What programming languages are you most comfortable with, and why?
- Answer aloud, timed: Can you explain the software development lifecycle you follow?
Deliverable: Spoken answers to 2 reported Technical / Domain Knowledge question(s), under time.
07Answer out loud: Problem-Solving / Case Studies
- Answer aloud, timed: If you were tasked with improving system efficiency, where would you start?
- Answer aloud, timed: Describe how you would approach debugging a complex software issue.
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 a time when you faced a conflict while working on a team. How did you handle it?
Describe a time when you faced a conflict while working on a team. 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?
Tell me about a situation where you demonstrated leadership in a project.
Tell me about a situation where you demonstrated leadership in a project.
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?
Explain a time when you had to adapt to significant changes at work.
Explain a time when you had to adapt to significant changes at 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
Describe a time when you faced a conflict while working on a team. How did you handle it?
- 02
Tell me about a situation where you demonstrated leadership in a project.
- 03
Explain a time when you had to adapt to significant changes at work.
What is the difficulty level of the interviews?
The interviews at Oncor are generally considered moderate in difficulty, with a focus on behavioral and situational questions. Candidates should prepare by reflecting on past experiences and practicing their responses.
Oncor Electric Delivery Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates typically demonstrate strong technical skills, effective communication abilities, and a clear alignment with Oncor's values. They showcase a collaborative spirit and a proactive approach to problem-solving.
Oncor Electric Delivery Software Engineer candidate reports ↗What is the culture and working style at Oncor Electric Delivery?
Oncor promotes a collaborative and supportive work environment. The team culture emphasizes innovation, continuous learning, and a commitment to delivering exceptional service to customers.
Oncor Electric Delivery Software Engineer candidate reports ↗What is the typical timeline from initial interview to offer?
The interview process may take a few weeks, with initial screenings followed by onsite interviews. Candidates can expect a timely response regarding their status throughout the process.
Oncor Electric Delivery Software Engineer candidate reports ↗Are remote work or hybrid options available?
While specific policies may vary, Oncor is open to flexible work arrangements depending on the role and business needs. Candidates should inquire about these options during the interview process.
Oncor Electric Delivery Software Engineer candidate reports ↗What topics does Oncor Electric Delivery test in interviews?
Oncor Electric Delivery interviews most often cover Behavioral Interviewing, Project Management, STAR Method for Behavioral Response, Customer Interconnects (Transmission Engineering), and Leadership & Leadership Qualities. The exact emphasis depends on the specific role you apply for.
Oncor Electric Delivery 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.
- 01Oncor Electric Delivery 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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