A Software Engineer at RSG - Resource Systems Group plays a critical role in developing innovative solutions that support complex resource management and decision-making processes. This position is integral to designing and implementing software that impacts a range of projects, from transportation and energy modeling to environmental management. Your work will not only enhance the efficiency of operations but also contribute significantly to the sustainability efforts that define RSG’s mission. In this role, you will collaborate with multidisciplinary teams to create robust software systems that process large datasets and facilitate advanced modeling techniques. You will contribute to products that serve a diverse user base, including government agencies and private sector clients, ultimately helping them make informed decisions based on data-driven insights. As a Software Engineer, you will face unique challenges that require a blend of technical expertise, problem-solving skills, and a passion for sustainability.
Initial Phone Screen
reportedCandidates begin with an initial phone screen to assess basic qualifications and fit.
What to demonstrate
- Candidates begin with an initial phone screen to assess basic qualifications and fit
- Depth in Python
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.
In-Depth Technical Interview
reportedA more detailed technical interview follows, focusing on technical skills and problem-solving abilities.
What to demonstrate
- A more detailed technical interview follows
- Focusing on technical skills and problem-solving abilities
How to prepare
- Answer aloud and timed: Describe a challenging technical problem you faced and how you resolved it.
- Answer aloud and timed: What experience do you have with data processing and analysis?
Final Round Discussions
reportedCandidates may have discussions with senior leadership or potential team members to evaluate cultural fit.
What to demonstrate
- Candidates may have discussions with senior leadership or potential team members to evaluate cultural fit
- Depth in Python
How to prepare
- Answer aloud and timed: How do you ensure code quality and maintainability in your projects?
- Answer aloud and timed: Describe a time you worked on a team project. What was your role, and how did you contribute to the team’s success?
PracHub editorial advice for the preparation topics above.
Research the Company
Understanding RSG's mission and current projects will help you tailor your responses and demonstrate your interest.
Practice Coding
If applicable, be sure to practice coding problems and familiarize yourself with data structures and algorithms.
Be Ready to Discuss Your Impact
Prepare concrete examples of how your work has made a difference in past roles, particularly in collaborative settings.
Embrace the Challenge
Approach the interviews with a positive mindset, viewing them as an opportunity to showcase your skills and learn more about RSG.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Write a function in Python that performs a specific data transformation.
Write a function in Python that performs a specific data transformation.
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 and any trade-offs involved.
Explain the time complexity of your solution and any trade-offs involved.
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?
Here is a coding challenge: [insert specific challenge].
Here is a coding challenge: [insert specific challenge].
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 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?
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?
What programming languages are you most comfortable with, and how have you used them in past projects?
What programming languages are you most comfortable with, and how have you used them in past projects?
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 concept of activity-based modeling and its application in software development?
Can you explain the concept of activity-based modeling and its application in software development?
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 a challenging technical problem you faced and how you resolved it.
Describe a challenging technical problem 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?
What experience do you have with data processing and analysis?
What experience do you have with data processing and analysis?
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 code quality and maintainability in your projects?
How do you ensure code quality and maintainability in your projects?
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 optimizing a software system for better performance?
How would you approach optimizing a software system for better performance?
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?
Walk us through your thought process in designing a solution for a specific user need.
Walk us through your thought process in designing a solution for a specific user need.
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 faced with a tight deadline, how would you prioritize tasks?
If faced with a tight deadline, how would you prioritize tasks?
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?
Edge instances grow 400 MB per hour until the nightly restart
Edge API instances start at 700 MB resident and grow about 400 MB/hour; a nightly rolling restart has hidden it for weeks. Growth continues unchanged when request rate halves overnight, p99 degrades in the last hours before an instance is recycled, and heap used immediately after a forced full GC rises monotonically. The service holds no product state. Name the discriminating measurement that separates the plausible causes, give the most likely cause, and give the fix and how you would verify it.
Approach
- Separate resident memory from live heap first, because they fail differently. Resident size can grow from fragmentation, native buffers or thread stacks while the heap is flat; heap used after a full GC rising monotonically is the measurement that says objects are reachable and not being released. You already have it, so this is retention, not fragmentation, and that closes off half the candidate list.
- Use the rate's independence from traffic as the discriminator. Growth that continues at half the request rate rules out per-request objects that are merely slow to collect and points at a structure that grows with distinct values observed rather than with call volume. Write the candidates that have that property: a metrics registry keyed on a high-cardinality label, an unevicted cache, an interner, a per-key lock map.
- Take two heap snapshots an hour apart and diff by retained size, reading the dominator tree, not by allocation count or instance count. Expect one root holding a map with millions of entries, then follow the reference chain to the code that inserts and never removes. Allocation profilers point at churn, which is the wrong signal here.
- The candidate that fits this service is an observability label carrying an identifier, such as a request path recorded before templating so that /v1/resources/48213 becomes its own metric series. That grows with distinct ids seen, is independent of rate, and explains the late p99 degradation, since GC cost rises with the size of the live set.
Follow-up
- Post-GC heap is now flat but resident size still creeps. What are you looking at, and does it matter?
- How would you have detected this before an OOM, given the nightly restart masked the trend?
Built from the rounds and topics RSG - Resource Systems Group candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the RSG - Resource Systems Group loop
- Write out the reported sequence: Initial Phone Screen, In-Depth Technical Interview, Final Round 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 Python
- Spend the session on Python, which RSG - Resource Systems Group candidates report being tested on.
- Write one worked example in Python and time yourself on it.
Deliverable: One timed worked example in Python.
03Work Activity-based modeling
- Spend the session on Activity-based modeling, which RSG - Resource Systems Group candidates report being tested on.
- Write one worked example in Activity-based modeling and time yourself on it.
Deliverable: One timed worked example in Activity-based modeling.
04Work Scripting (general)
- Spend the session on Scripting (general), which RSG - Resource Systems Group candidates report being tested on.
- Write one worked example in Scripting (general) and time yourself on it.
Deliverable: One timed worked example in Scripting (general).
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: What programming languages are you most comfortable with, and how have you used them in past projects?
- Answer aloud, timed: Can you explain the concept of activity-based modeling and its application in software development?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a time you worked on a team project. What was your role, and how did you contribute to the team’s success?
- Answer aloud, timed: How do you handle conflicts or disagreements with team members?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
07Answer out loud: Problem-solving / Case Studies
- Answer aloud, timed: How would you approach optimizing a software system for better performance?
- Answer aloud, timed: Walk us through your thought process in designing a solution for a specific user need.
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 you worked on a team project. What was your role, and how did you contribute to the team’s suc
Describe a time you worked on a team project. What was your role, and how did you contribute to the 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?
How do you handle conflicts or disagreements with team members?
How do you handle conflicts or 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?
Can you give an example of a time when you had to adapt quickly to a change in project requirements?
Can you give an example of a time when you had to adapt quickly to a change in project requirements?
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 know about RSG, and why do you want to work here?
What do you know about RSG, and why do you want to work here?
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 you worked on a team project. What was your role, and how did you contribute to the team’s success?
- 02
How do you handle conflicts or disagreements with team members?
- 03
Can you give an example of a time when you had to adapt quickly to a change in project requirements?
- 04
What do you know about RSG, and why do you want to work here?
How difficult is the interview process, and how much preparation time is typical?
The interview process can be challenging, with a strong emphasis on both technical skills and cultural fit. Candidates typically spend several weeks preparing, focusing on relevant technologies and behavioral questions.
RSG - Resource Systems Group Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often exhibit a strong alignment with RSG's values, technical expertise in relevant areas, and the ability to communicate effectively with diverse teams.
RSG - Resource Systems Group Software Engineer candidate reports ↗What is the culture and working style at RSG - Resource Systems Group?
The culture at RSG is collaborative and focused on sustainability. Employees are encouraged to work together across disciplines and prioritize innovative solutions to complex challenges.
RSG - Resource Systems Group Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The timeline can vary, but candidates can expect the process to take several weeks, including multiple rounds of interviews and assessments.
RSG - Resource Systems Group Software Engineer candidate reports ↗Are there remote work or hybrid expectations?
RSG supports flexible work arrangements, and candidates should inquire about specific policies during their interviews.
RSG - Resource Systems Group Software Engineer candidate reports ↗What topics does RSG - Resource Systems Group test in interviews?
RSG - Resource Systems Group interviews most often cover Data Analysis, Market Research, Business Analysis, Python, and Financial Analysis. The exact emphasis depends on the specific role you apply for.
RSG - Resource Systems Group 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.
- 01RSG - Resource Systems Group 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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