The role of a Software Engineer at The Church of Jesus Christ of Latter-day Saints is pivotal in shaping the digital landscape of the Church’s services and outreach. As a Software Engineer, you will be tasked with creating and maintaining applications that facilitate the mission of the Church, enhancing the experience of users through technology. This role significantly impacts both the internal workings of the Church and the external services provided to its members worldwide. Your contributions will be directed toward various projects, including managing databases, developing web applications, and ensuring that the Church's online services are reliable and user-friendly. You will work alongside teams that are dedicated to advancing the Church's digital presence, including contributions to platforms like FamilySearch and other communal resources. The complexity and scale of the projects you will engage with make this role both challenging and rewarding, emphasizing the importance of your technical expertise and collaborative spirit. Expect to be involved in innovative problem-solving, utilizing cutting-edge technologies to build scalable solutions that align with the Church’s vision and values. This role not only demands technical proficiency but also a commitment to service and the mission of the Church.
Initial Screening
reportedThe process begins with an initial screening to evaluate candidate fit.
What to demonstrate
- The process begins with an initial screening to evaluate candidate fit
- Depth in Coding Skills (General)
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 programming skills.
What to demonstrate
- Candidates undergo technical assessments to evaluate their programming skills
- Depth in Coding Skills (General)
How to prepare
- Answer aloud and timed: Describe your experience with databases and how you have implemented them in past projects.
- Answer aloud and timed: Write a function to reverse a string in your preferred programming language.
Behavioral Interviews
reportedBehavioral interviews assess cultural fit and teamwork capabilities.
What to demonstrate
- Behavioral interviews assess cultural fit and teamwork capabilities
- Depth in Coding Skills (General)
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.
Coding Challenges
reportedCandidates complete coding challenges to demonstrate their problem-solving abilities.
What to demonstrate
- Candidates complete coding challenges to demonstrate their problem-solving abilities
- Depth in Coding Skills (General)
How to prepare
- Answer aloud and timed: Describe a challenging project you worked on and how you overcame difficulties.
- Answer aloud and timed: How do you prioritize tasks when managing multiple deadlines?
System Design Discussions
reportedDiscussions focus on system design principles and scalability.
What to demonstrate
- Discussions focus on system design principles and scalability
- Depth in Coding Skills (General)
How to prepare
- Answer aloud and timed: Can you give an example of how you have worked collaboratively within a team?
- Answer aloud and timed: How would you approach designing a new feature for an existing application?
PracHub editorial advice for the preparation topics above.
Understand the Mission
Familiarize yourself with the Church’s mission and values. This will help you align your responses with what the interviewers are looking for.
Practice Coding
Regularly practice coding challenges on platforms like LeetCode or HackerRank to sharpen your skills before the interview.
Prepare Questions
Prepare thoughtful questions to ask your interviewers about the team, projects, and company culture. This demonstrates your genuine interest in the role.
Show Your Process
During coding interviews, communicate your thought process clearly as you solve problems. This helps interviewers understand your approach and reasoning.
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 sorting algorithm for a large dataset?
How would you optimize a sorting algorithm for a large dataset?
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 a list of integers, write a function to find the two numbers that add up to a specific target.
Given a list of integers, write a function to find the 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?
Find version gaps and relay lag with window functions
outbox_event holds event_id, aggregate_type, aggregate_id, aggregate_version, event_type, payload, status ('pending','published','dead'), attempts, created_at, published_at. A projection is missing rows and you must decide whether the relay skipped events or the consumer dropped them. Write three queries over the last seven days: one listing every aggregate_id whose published aggregate_version sequence has a hole, one giving per-day counts with a running total, and one returning the newest published event per aggregate. For each, say where the window function is evaluated relative to WHERE and LIMIT. PostgreSQL 16.
Approach
- Gaps: compute lead(aggregate_version) OVER (PARTITION BY aggregate_id ORDER BY aggregate_version) in a subquery, then filter next_version <> aggregate_version + 1 in the outer query. Window functions are evaluated after WHERE, GROUP BY and HAVING and before the outer ORDER BY and LIMIT, so the predicate cannot sit in the same WHERE clause and PostgreSQL 16 has no QUALIFY.
- Say what the seven-day filter does to the answer: it truncates every partition, so the first row per aggregate has no predecessor inside the window and a hole spanning the boundary is invisible. Widen the window, or join to resource.version as the authority for the true maximum.
- Running total: SELECT date_trunc('day', created_at) AS d, count() AS n, sum(count()) OVER (ORDER BY date_trunc('day', created_at) ROWS UNBOUNDED PRECEDING). An aggregate inside a window call is legal because grouping runs before windowing. The grouping key is unique per row here so ROWS and RANGE agree, but write the frame anyway — over ungrouped rows with tied timestamps the default RANGE frame pulls in every peer row and the total jumps.
- Newest per aggregate: DISTINCT ON (aggregate_id) ... ORDER BY aggregate_id, aggregate_version DESC is the cheap PostgreSQL-only form when an index matches that order; row_number() OVER (PARTITION BY aggregate_id ORDER BY aggregate_version DESC) = 1 is the portable form and needs a subquery for the same evaluation-order reason as the gap query.
Follow-up
- Relay failover redelivers events. Does a duplicate break the gap query, and how would you detect one from this table alone?
- Turn the gap check into a continuous monitor rather than a query someone runs after an incident. What does it watch?
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?
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 difference between object-oriented and functional programming?
Can you explain the difference between object-oriented and functional 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 would you approach designing a new feature for an existing application?
How would you approach designing a new feature for an existing application?
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 encountered a bug that you couldn’t resolve immediately, what steps would you take?
If you encountered a bug that you couldn’t resolve immediately, what steps would you take?
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 design an API for a new service.
Describe how you would design an API for a new service.
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 considerations would you take into account when scaling a web application?
What considerations would you take into account when scaling a 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?
Listing latency scales with page size, not with filters
The tenant listing endpoint reads resource filtered by tenant_id and status, ordered by updated_at DESC, and returns each row plus the owner's display name from app_user and the actor of that resource's latest resource_revision. p99 is 55 ms at 10 rows per page and 1.4 s at 200. Database telemetry shows 401 statements per request, each under 1 ms, and nothing in the slow-query log. Diagnose the cause and give the fix, stating the statement count per request and the p99 you expect afterwards.
Approach
- Read the counters before forming a theory. 401 statements for 200 rows is one driver query plus two per row, and sub-millisecond execution with an empty slow-query log rules out a bad plan. The time is round trips, which is why it is invisible in every per-query metric and scales with rows returned rather than with filter selectivity.
- Name the two per-row statements from their normalised text: a single-row app_user lookup by user_id, and a resource_revision lookup by resource_id ordered by version DESC LIMIT 1. Confirm by dropping those two response fields and watching the statement count fall to one. That locates the calls in the serialisation layer, not the repository.
- Check that the arithmetic accounts for the whole gap. Measure one round trip to the replica in isolation; 400 trips at roughly 3 ms of network plus 0.2 ms of execution is about 1.3 s on top of a 55 ms baseline, which matches. If the multiplication had fallen short, the N+1 would only be part of the story and you would keep looking.
- Batch both lookups. Collect owner_user_ids and resource_ids from the driver query, then issue WHERE tenant_id = $1 AND user_id = ANY($2) for the users, and PostgreSQL's SELECT DISTINCT ON (resource_id) ... WHERE resource_id = ANY($2) ORDER BY resource_id, version DESC for the latest revision, which the UNIQUE (resource_id, version) index serves directly. On an engine without DISTINCT ON, use a lateral join or a row_number window. Three statements per request at any page size.
Follow-up
- The page size is capped at 200 today. What breaks first if it is raised to 2,000, and is it still this bug?
- How do you stop the next N+1 from reaching production, given that no individual query is slow and the endpoint's tests pass?
Built from the rounds and topics The Church of Jesus Christ of Latter-day Saints candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the The Church of Jesus Christ of Latter-day Saints loop
- Write out the reported sequence: Initial Screening, Technical Assessments, Behavioral Interviews, Coding Challenges, System Design 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 5 reported rounds, with the weakest marked.
02Work Coding Skills (General)
- Spend the session on Coding Skills (General), which The Church of Jesus Christ of Latter-day Saints candidates report being tested on.
- Write one worked example in Coding Skills (General) and time yourself on it.
Deliverable: One timed worked example in Coding Skills (General).
03Work Problem Solving
- Spend the session on Problem Solving, which The Church of Jesus Christ of Latter-day Saints candidates report being tested on.
- Write one worked example in Problem Solving and time yourself on it.
Deliverable: One timed worked example in Problem Solving.
04Work Database Design / Database Concepts
- Spend the session on Database Design / Database Concepts, which The Church of Jesus Christ of Latter-day Saints candidates report being tested on.
- Write one worked example in Database Design / Database Concepts and time yourself on it.
Deliverable: One timed worked example in Database Design / Database Concepts.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: What programming languages are you most comfortable with, and why?
- Answer aloud, timed: Can you explain the difference between object-oriented and functional programming?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Coding / Algorithms
- Answer aloud, timed: Write a function to reverse a string in your preferred programming language.
- Answer aloud, timed: How would you optimize a sorting algorithm for a large dataset?
Deliverable: Spoken answers to 2 reported Coding / Algorithms question(s), under time.
07Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a challenging project you worked on and how you overcame difficulties.
- Answer aloud, timed: How do you prioritize tasks when managing multiple deadlines?
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 your experience with databases and how you have implemented them in past projects.
Describe your experience with databases and how you have implemented them in past 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?
Describe a challenging project you worked on and how you overcame difficulties.
Describe a challenging project you worked on and how you overcame difficulties.
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 deadlines?
How do you prioritize tasks when managing multiple deadlines?
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 have worked collaboratively within a team?
Can you give an example of how you have worked collaboratively 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?
- 01
Describe your experience with databases and how you have implemented them in past projects.
- 02
Describe a challenging project you worked on and how you overcame difficulties.
- 03
How do you prioritize tasks when managing multiple deadlines?
- 04
Can you give an example of how you have worked collaboratively within a team?
How difficult are the interviews, and how much preparation time is typical?
The interviews vary in difficulty but generally require a solid understanding of technical concepts and problem-solving skills. Candidates typically spend 2-4 weeks preparing to ensure they are familiar with relevant technologies and interview formats.
The Church of Jesus Christ of Latter-day Saints Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates demonstrate not only technical expertise but also a strong alignment with the Church’s values, showcasing collaboration and a service-oriented mindset.
The Church of Jesus Christ of Latter-day Saints Software Engineer candidate reports ↗What is the culture like at The Church of Jesus Christ of Latter-day Saints?
The culture emphasizes teamwork, integrity, and a mission-driven approach. Employees are encouraged to support one another and work collectively towards common goals.
The Church of Jesus Christ of Latter-day Saints Software Engineer candidate reports ↗What is the typical timeline from the initial screen to an offer?
The process can vary, but candidates usually receive feedback within a few weeks after their initial interview. The entire process may take several weeks, depending on scheduling and availability.
The Church of Jesus Christ of Latter-day Saints Software Engineer candidate reports ↗Are remote work or hybrid options available?
While many positions are based on-site, there may be opportunities for remote or hybrid work, depending on the specific role and team requirements.
The Church of Jesus Christ of Latter-day Saints Software Engineer candidate reports ↗What topics does The Church of Jesus Christ of Latter-day Saints test in interviews?
The Church of Jesus Christ of Latter-day Saints interviews most often cover Problem Solving, Stakeholder Management, Communication Skills, Behavioral Interviewing, and Data Interpretation. The exact emphasis depends on the specific role you apply for.
The Church of Jesus Christ of Latter-day Saints 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.
- 01The Church of Jesus Christ of Latter-day Saints 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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