At Thorson Baker & Associates (TBA), a Software Engineer—often integrated within our Technology Project Engineer and engineering automation tracks—plays a critical role in bridging the gap between software development and physical engineering disciplines. Unlike traditional tech companies, TBA is a premier consulting engineering firm. This means our engineering software teams design, build, and optimize the computational tools, BIM (Building Information Modeling) workflows, and custom automation scripts that our structural, mechanical, and electrical design teams use to engineer complex building systems. Your work directly impacts the safety, efficiency, and execution of major structural and MEP (Mechanical, Electrical, Plumbing) projects across the United States. Whether you are developing custom APIs to automate load calculations or building internal tools to streamline structural design methods, your software ensures that our physical engineering designs are accurate, scalable, and delivered on schedule. This role requires a unique dual-minded professional: someone who possesses strong software development capabilities while maintaining a deep respect and baseline understanding of core engineering principles. You will collaborate directly with multidisciplinary teams, translating physical engineering requirements—such as structural load distributions and electrical system designs—into elegant, maintainable code.
Resume Review
reportedInitial evaluation of candidate's resume to determine fit for the role.
What to demonstrate
- Initial evaluation of candidate's resume to determine fit for the role
- Depth in Engineering rationale / design justification
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.
Phone Screen
reportedBrief phone screen or direct invitation to the office following resume review.
What to demonstrate
- Brief phone screen or direct invitation to the office following resume review
- Depth in Engineering rationale / design justification
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-site Interview
reportedComprehensive interview conducted by a panel of senior engineers in a collaborative setting.
What to demonstrate
- Comprehensive interview conducted by a panel of senior engineers in a collaborative setting
- Depth in Engineering rationale / design justification
How to prepare
- Answer aloud and timed: Explain the concept of tributary area and how you would structure an algorithm to calculate it.
- Answer aloud and timed: Walk us through a shear-moment diagram and describe how you would programmatically represent these shear and moment forces.
Technical Assessment
reportedHands-on technical assessment focused on engineering fundamentals following the verbal interview.
What to demonstrate
- Hands-on technical assessment focused on engineering fundamentals following the verbal interview
- Depth in Engineering rationale / design justification
How to prepare
- Answer aloud and timed: How would you structure a database to manage building components and their respective engineering properties?
- Answer aloud and timed: Describe your approach to validating the accuracy of a software tool designed to calculate structural loads.
Company Tour
reportedTour of the company floor to observe engineering departments and team collaboration.
What to demonstrate
- Tour of the company floor to observe engineering departments and team collaboration
- Depth in Engineering rationale / design justification
How to prepare
- Answer aloud and timed: Why do you want to work specifically for Thorson Baker & Associates rather than a generic software firm?
- Answer aloud and timed: Describe a situation where you had to collaborate with professionals from a different technical discipline. How did you ensure clear communication?
PracHub editorial advice for the preparation topics above.
Research Our Projects
TBA has a highly informative website showcasing our involvement in diverse commercial, retail, educational, and institutional projects. Be ready to discuss specific projects that interest you and why you want to contribute to our firm's portfolio.
Brush Up on the Basics
Do not let simple structural or mechanical concepts slip your mind. Spend an hour reviewing basic statics, load distributions, and beam diagrams before your interview.
Be Conversational
Our principals want to see how you would fit into our collaborative office environment. Treat the interview as a dialogue about engineering design rather than a stiff question-and-answer session.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Explain the concept of tributary area and how you would structure an algorithm to calculate it.
Explain the concept of tributary area and how you would structure an algorithm to calculate it.
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?
Diff a projection against the primary without per-row point reads
The listing projection has drifted and some rows show a stale version. The primary holds 40,000,000 resource rows across 12,000 tenants while serving 1,200 writes and 14,000 reads per second. The obvious repair, reading each resource row and comparing its version against the projection, is correct and would eventually finish. Explain precisely why it is unacceptable here, then give a diff that finds the differing rows, state its complexity, and make it safe to run against a live primary. Replication lag is usually under 100 ms and is not bounded.
Approach
- Quantify the naive cost rather than calling it slow: 40,000,000 point reads at even 0.5 ms each is over five hours serialised, and the only lever is concurrency, which is exactly what you cannot spend. The primary's pool is sized for the write path, and 40,000,000 random reads evict the buffer cache that sustains the 85 percent cache hit rate, so the audit degrades the system it is auditing.
- Replace random access with one ordered pass per side. Both sides can be read in (tenant_id, resource_id) order, which is a sequential scan on each and a merge join in O(n) time and O(1) memory. For a dense diff that is the whole answer, and it reads the primary once instead of 40,000,000 times.
- For the expected sparse case, compare range hashes instead of rows: partition the key space, compute per range an order-independent aggregate over hash(resource_id, version), compare aggregates, and descend only into ranges that differ. With d differing rows and branching factor B, at most d ranges mismatch per level, so the drill-down examines O(d log_B(n/d)) ranges and reads full rows only in mismatching leaves.
- Aggregate with a sum modulo 2^64 or a multiset hash, never XOR. XOR is order-independent but self-cancelling, so two rows wrong in the same way, or a row duplicated on one side, leave the range aggregate matching and the range is declared clean.
Follow-up
- The diff reports 900 stale rows. How do you decide between patching those rows and rebuilding the projection from resource_revision?
- Same job, but the projection lives in a search index that cannot be scanned in key order. What changes?
Find overlapping job attempts and peak concurrency from lease records
A day of job_run history yields about 50,000,000 attempt records: (job_run_id, job_type, attempt, started_at, finished_at which is NULL when the worker died, lease_expires_at). Leases expire on a clock, so a job that outran its lease ran twice. Produce (a) every job_run_id whose attempts overlapped in wall-clock time and (b) the peak number of simultaneously running attempts per job_type with the minute it occurred. Target O(n log n). State how you treat a NULL finished_at and what clock skew does to your answer.
Approach
- Define the interval before sorting anything: an attempt occupies [started_at, COALESCE(finished_at, lease_expires_at)). finished_at is observed and lease_expires_at is only a promise, so every attempt without a finish contributes an estimate and the whole result is a lower bound on overlap rather than an exact count.
- For peak concurrency, sweep: emit 2n endpoints, sort by (timestamp, kind) with ends ordered before starts at equal timestamps, then walk the sequence maintaining a counter per job_type and record each type's maximum with its timestamp. O(n log n) dominated by the sort, O(n) space, or O(1) extra if the sort is external and the walk streams.
- For overlap detection, do not compare attempts pairwise. A single global sort by (job_run_id, started_at) gives both the grouping and the order; within a group, keep the maximum end seen so far and report an overlap exactly when the next start is less than that running maximum, which is one linear pass after the sort.
- Half-open intervals matter and are easy to get wrong: with closed intervals an attempt ending at the same millisecond another begins reads as concurrency two, and across 50,000,000 records that artefact swamps the real signal.
Follow-up
- A handler is not idempotent and you have found 400 overlapping jobs. Which of them actually caused damage, and what would you query to find out?
- Peak concurrency for one job_type is 4 against a configured cap of 4. Is the cap working, or is the data hiding attempts that never started?
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?
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?
Walk me through a complex technical project on your resume and explain your specific contributions.
Walk me through a complex technical project on your resume and explain your specific contributions.
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 programming languages and development environments are you most comfortable using, and why?
What programming languages and development environments are you most comfortable using, 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?
Walk us through a shear-moment diagram and describe how you would programmatically represent these shear and m
Walk us through a shear-moment diagram and describe how you would programmatically represent these shear and moment forces.
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 structure a database to manage building components and their respective engineering properties?
How would you structure a database to manage building components and their respective engineering properties?
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 your approach to validating the accuracy of a software tool designed to calculate structural loads.
Describe your approach to validating the accuracy of a software tool designed to calculate structural loads.
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?
Exports duplicate a row range about once a week
Roughly once a week an export writes a file containing a duplicated range of rows. The affected job_run rows show attempt = 1, status = succeeded, one started_at, and a lease_owner naming a different host from the one whose logs show the job starting. Leases last 30 seconds and are heartbeated every 10 from inside the handler; lease_expires_at is computed on the worker and compared against the database's now(). Find the mechanism, and give a fix that holds even if you cannot fix the clocks.
Approach
- Start from the fact that eliminates the obvious answer. attempt = 1 means no retry was recorded, so this is not a re-run after failure; two workers ran the same row concurrently and the takeover path never touched the counter. lease_owner naming a host other than the one that started the job is the same statement from the other side.
- Enumerate the mechanisms that cause a premature takeover, then find the signal that separates them. Either the lease genuinely expired because the heartbeat did not fire, which is what happens when the heartbeat runs on the handler's own thread and the handler makes a long blocking call, or it only appeared expired because two clocks disagree, since lease_expires_at is written from the worker's clock and evaluated against the database's. The discriminator is the distribution: incidents clustered on the longest exports indict the heartbeat, incidents clustered on one host indict skew. Measure both, and measure each host's offset against the database directly.
- Read the reclaim query precisely. In PostgreSQL now() is transaction start time, not statement time, so a reclaimer holding a long transaction compares against an older timestamp than expected; clock_timestamp() is the statement-time function. This is worth ruling in or out before you redesign anything, because it changes which rows look expired.
- Remove the second clock rather than trying to synchronise it. Issue and extend the lease in the database, with lease_expires_at = now() + interval '30 seconds' in both the claim and the heartbeat, so exactly one clock is ever compared and worker skew stops mattering to this predicate.
Follow-up
- The displaced worker has already streamed half the file to object storage. What makes that side effect safe to repeat?
- You now count takeovers. What alert fires on that counter, and at what threshold?
Built from the rounds and topics Thorson Baker & Associates candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Thorson Baker & Associates loop
- Write out the reported sequence: Resume Review, Phone Screen, On-site Interview, Technical Assessment, Company Tour.
- 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 Engineering rationale / design justification
- Spend the session on Engineering rationale / design justification, which Thorson Baker & Associates candidates report being tested on.
- Write one worked example in Engineering rationale / design justification and time yourself on it.
Deliverable: One timed worked example in Engineering rationale / design justification.
03Work Building components design
- Spend the session on Building components design, which Thorson Baker & Associates candidates report being tested on.
- Write one worked example in Building components design and time yourself on it.
Deliverable: One timed worked example in Building components design.
04Work Structural analysis concepts
- Spend the session on Structural analysis concepts, which Thorson Baker & Associates candidates report being tested on.
- Write one worked example in Structural analysis concepts and time yourself on it.
Deliverable: One timed worked example in Structural analysis concepts.
05Answer out loud: Resume & Professional Experience
- Answer aloud, timed: Walk me through a complex technical project on your resume and explain your specific contributions.
- Answer aloud, timed: Describe a time when you had to translate a highly technical, non-software requirement into a functional software tool.
Deliverable: Spoken answers to 2 reported Resume & Professional Experience question(s), under time.
06Answer out loud: Engineering Fundamentals & Design Rationale
- Answer aloud, timed: Explain the concept of tributary area and how you would structure an algorithm to calculate it.
- Answer aloud, timed: Walk us through a shear-moment diagram and describe how you would programmatically represent these shear and moment forces.
Deliverable: Spoken answers to 2 reported Engineering Fundamentals & Design Rationale question(s), under time.
07Answer out loud: Behavioral & Alignment Questions
- Answer aloud, timed: Why do you want to work specifically for Thorson Baker & Associates rather than a generic software firm?
- Answer aloud, timed: Describe a situation where you had to collaborate with professionals from a different technical discipline. How did you ensure clear communication?
Deliverable: Spoken answers to 2 reported Behavioral & Alignment Questions 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 had to translate a highly technical, non-software requirement into a functional softw
Describe a time when you had to translate a highly technical, non-software requirement into a functional software tool.
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 working with legacy systems or undocumented internal tools?
How do you handle working with legacy systems or undocumented internal tools?
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?
Why do you want to work specifically for Thorson Baker & Associates rather than a generic software firm?
Why do you want to work specifically for Thorson Baker & Associates rather than a generic software firm?
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 collaborate with professionals from a different technical discipline. Ho
Describe a situation where you had to collaborate with professionals from a different technical discipline. How did you ensure clear communication?
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 tight deadlines and shifting priorities in a fast-paced project environment?
How do you handle tight deadlines and shifting priorities in a fast-paced project environment?
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 interests you most about the intersection of software development and physical building design?
What interests you most about the intersection of software development and physical building design?
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 had to translate a highly technical, non-software requirement into a functional software tool.
- 02
How do you handle working with legacy systems or undocumented internal tools?
- 03
Why do you want to work specifically for Thorson Baker & Associates rather than a generic software firm?
- 04
Describe a situation where you had to collaborate with professionals from a different technical discipline. How did you ensure clear communication?
How technical is the physical engineering assessment for a software role?
The assessment focuses on fundamental engineering principles rather than highly advanced formulas. You should be comfortable with basic mechanics, such as calculating tributary areas, drawing shear-moment diagrams, and understanding how forces travel through building components.
Thorson Baker & Associates Software Engineer candidate reports ↗What is the interview format like?
The interview is highly conversational and typically takes place in person with two or three senior engineers or principals. Expect to discuss your resume, walk through your design rationale for past projects, take a short paper-and-pencil engineering quiz, and tour the office floor. Some candidates find the presence of multiple founding principals in the room intimidating. Remember that they are there to gauge your communication and problem-solving process, not to trip you up. Stay calm, speak clearly, and walk through your logic step-by-step.
Thorson Baker & Associates Software Engineer candidate reports ↗How fast does the hiring team make decisions?
Thorson Baker & Associates is known for an efficient hiring process. Successful candidates frequently receive job offers within five business days of their on-site interview.
Thorson Baker & Associates Software Engineer candidate reports ↗Is there a hybrid or remote option for this role?
Our technology and engineering teams work closely together to coordinate project deliveries. While some flexibility exists, our culture heavily emphasizes on-site collaboration and mentoring, which is why the interview process includes an in-person office tour.
Thorson Baker & Associates Software Engineer candidate reports ↗What topics does Thorson Baker & Associates test in interviews?
Thorson Baker & Associates interviews most often cover Electrical systems design (buildings), Engineering rationale / design justification, Construction administration, Building components design, and AutoCAD. The exact emphasis depends on the specific role you apply for.
Thorson Baker & Associates 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.
- 01Thorson Baker & Associates 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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