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Teco Westinghouse Software Engineer Interview Guide

Teco Westinghouse Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

A Software Engineer at Teco Westinghouse occupies a highly specialized and critical role at the intersection of physical power systems, advanced control theory, and embedded software. Unlike traditional software roles focused on high-level web applications, software engineering here is deeply intertwined with heavy industrial hardware, power electronics, and data center infrastructure. You will design, develop, and optimize the firmware and control algorithms that govern massive electric motors, variable frequency drives, and high-capacity power distribution systems. Your work directly impacts the reliability and efficiency of critical infrastructure around the globe. From engineering smart control systems for mega-scale data centers to optimizing the performance of high-voltage industrial generators, your code dictates physical behavior in real-time.

This guide is scoped to a Software Engineer candidate at Teco Westinghouse.

Focus areas

  • Hardware description languages (HDL)
  • Verilog
  • VHDL

The Teco Westinghouse interview process

Teco Westinghouse candidates report 4 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

HR Vetting Call

Initial call to discuss your background, career goals, and alignment with the team's needs.

What to demonstrate

  • Initial call to discuss your background, career goals, and alignment with the team's needs
  • Depth in Hardware description languages (HDL)

How to prepare

  • Answer aloud and timed: Explain the process of writing a state machine in Verilog or VHDL and how to prevent race conditions during state transitions.
  • Answer aloud and timed: How do you handle clock domain crossing in a multi-clock FPGA design?

Technical Phone Screen

One-on-one phone or video discussion focusing on engineering principles and past design choices.

What to demonstrate

  • One-on-one phone or video discussion focusing on engineering principles and past design choices
  • Depth in Hardware description languages (HDL)

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.

Practical Assessment

Half-day project-based test involving review of board layout or writing a functional module in Verilog or VHDL.

What to demonstrate

  • Half-day project-based test involving review of board layout or writing a functional module in Verilog or VHDL
  • Depth in Hardware description languages (HDL)

How to prepare

  • Answer aloud and timed: Describe how you would debug a timing violation in a VHDL synthesis report.
  • Answer aloud and timed: During a board layout review, what critical steps do you take to isolate sensitive analog control lines from high-noise switching components?

In-Person Interview

Intensive interview at the Round Rock or Austin facility, presenting technical solutions and engaging in system-design discussions.

What to demonstrate

  • Intensive interview at the Round Rock or Austin facility, presenting technical solutions and engaging in system-design discussions
  • Depth in Hardware description languages (HDL)

How to prepare

  • Answer aloud and timed: How does parasitic inductance in a PCB layout affect the switching characteristics of power MOSFETs, and how do you compensate for this in software?
  • Answer aloud and timed: Explain how you would diagnose a suspected signal integrity issue on a high-speed communication bus.

Where candidates lose points

Showcase Your Lab Experience

Do not hesitate to talk about your hands-on laboratory experiences. Mentioning your familiarity with specific test equipment, physical debugging techniques, and safety protocols carries significant weight.

Prepare for the "Colloquium" Style

Expect long, deep discussions about engineering principles rather than rapid-fire technical trivia. Be ready to explain your design philosophy, defend your engineering choices, and listen constructively to alternative viewpoints.

Emphasize Safety

In high-power systems engineering, safety is a core value. Whenever you describe your past projects or solve hypothetical design problems, explicitly mention how you incorporated fail-safes, fault detection, and safety margins into your software.

Questions & practice

Explain the process of writing a state machine in Verilog or VHDL and how to prevent race conditions during st

Medium · Embedded Systems & Hardware Description

Explain the process of writing a state machine in Verilog or VHDL and how to prevent race conditions during state transitions.

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

How do you handle clock domain crossing in a multi-clock FPGA design?

Medium · Embedded Systems & Hardware Description

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Walk me through how you would write a driver to communicate with an external ADC over an SPI interface.

Medium · Embedded Systems & Hardware Description

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

What are the trade-offs between implementing a control loop in dedicated hardware (FPGA) versus software (micr

Medium · Embedded Systems & Hardware Description

What are the trade-offs between implementing a control loop in dedicated hardware (FPGA) versus software (microcontroller/DSP)?

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Find version gaps and relay lag with window functions

Medium · window functions · event tables · frame semantics

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

  1. 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.
  2. 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.
  3. 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.
  4. 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?

Keep soft-deleted accounts from blocking re-registration

Easy · soft delete · unique constraints · engine differences

app_user holds user_id, tenant_id, email CITEXT, password_hash (NULL for SSO principals), email_verified_at, auth_version, status ('invited','active','suspended','deactivated'), created_at, updated_at, deleted_at. Two live accounts for one address inside a tenant must be impossible, but an address freed by a soft delete must be reusable, and the same tenant may delete and re-register it repeatedly. Write the uniqueness DDL for PostgreSQL 16, then the equivalent for MySQL 8 where partial indexes do not exist, and say what each permits once three deleted rows already hold that address.

Approach

  1. Start from what is actually unique: not (tenant_id, email), but (tenant_id, email) among live rows. PostgreSQL says that directly — CREATE UNIQUE INDEX app_user_live_email ON app_user (tenant_id, email) WHERE deleted_at IS NULL. A full constraint over the same two columns burns the address permanently the first time someone deletes an account.
  2. Keep case-insensitivity in the type or the index, never in the application: CITEXT as given, or UNIQUE (tenant_id, lower(email)) as an expression index where the extension is unavailable. A case-sensitive unique column is exactly how two accounts for one human appear.
  3. For MySQL 8 the predicate has to move inside the key: add a discriminator column that is a constant 0 while the row is live and is set to user_id on delete, with UNIQUE (tenant_id, email, deleted_marker). Live rows share the constant and still collide; deleted rows differ from each other and stop colliding.
  4. State the NULL variant and its dependency: leaving the marker NULL for deleted rows also works, because a unique index treats NULLs as distinct — true in MySQL, and true in PostgreSQL only under the default NULLS DISTINCT, which PostgreSQL 15 lets you reverse. Check the polarity against the three existing deleted rows: constant-on-live is what preserves the collision you want, and reversing it silently admits duplicate live accounts.

Follow-up

  • A deleted account re-registers with the same address the next day. Do the old resource rows follow the new user_id, and how does the API keep the two principals apart?
  • How do you honour an erasure request while resource_revision.actor_user_id still references this table?

During a board layout review, what critical steps do you take to isolate sensitive analog control lines from h

Medium · Board Layout & Hardware Co-Design

During a board layout review, what critical steps do you take to isolate sensitive analog control lines from high-noise switching components?

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 does parasitic inductance in a PCB layout affect the switching characteristics of power MOSFETs, and how d

Medium · Board Layout & Hardware Co-Design

How does parasitic inductance in a PCB layout affect the switching characteristics of power MOSFETs, and how do you compensate for this in software?

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Explain how you would diagnose a suspected signal integrity issue on a high-speed communication bus.

Medium · Board Layout & Hardware Co-Design

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 key parameters do you look for when analyzing an oscilloscope capture of a noisy SPI data line?

Medium · Board Layout & Hardware Co-Design

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Explain the difference between scalar control (V/Hz) and vector control (Field Oriented Control) in AC inducti

Medium · Power Electronics & Control Systems Prin

Explain the difference between scalar control (V/Hz) and vector control (Field Oriented Control) in AC induction motors.

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 mathematically model and tune a PID controller for a system with significant thermal inertia?

Medium · Power Electronics & Control Systems Prin

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 the operating principles of a three-phase inverter and how space vector pulse width modulation

Medium · Power Electronics & Control Systems Prin

Walk us through the operating principles of a three-phase inverter and how space vector pulse width modulation (SVPWM) is used to control it.

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 approach designing system architecture when the hardware specifications are still highly fluid or i

Medium · Behavioral & Engineering Philosophy

How do you approach designing system architecture when the hardware specifications are still highly fluid or incomplete?

Approach

  1. Fix the scope first: who calls this, how often, and what they do when it fails.
  2. Name the read and write paths separately; they rarely have the same bottleneck.
  3. Choose a partition key and say what query it makes expensive.
  4. 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?

Describe how you would debug a timing violation in a VHDL synthesis report.

Medium · Embedded Systems & Hardware Description

Approach

  1. Establish what changed and when, before forming any theory.
  2. Pick a bisection that eliminates candidates whichever way it turns out.
  3. Check the instrumentation before believing the symptom.
  4. 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?

Suggested practice checklist

Built from the rounds and topics Teco Westinghouse candidates report.

Day 1 — Map the Teco Westinghouse loop

  • Write out the reported sequence: HR Vetting Call, Technical Phone Screen, Practical Assessment, In-Person 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 4 reported rounds, with the weakest marked.

Day 2 — Work Hardware description languages (HDL)

  • Spend the session on Hardware description languages (HDL), which Teco Westinghouse candidates report being tested on.
  • Write one worked example in Hardware description languages (HDL) and time yourself on it.

Deliverable: One timed worked example in Hardware description languages (HDL).

Day 3 — Work Verilog

  • Spend the session on Verilog, which Teco Westinghouse candidates report being tested on.
  • Write one worked example in Verilog and time yourself on it.

Deliverable: One timed worked example in Verilog.

Day 4 — Work VHDL

  • Spend the session on VHDL, which Teco Westinghouse candidates report being tested on.
  • Write one worked example in VHDL and time yourself on it.

Deliverable: One timed worked example in VHDL.

Day 5 — Answer out loud: Embedded Systems & Hardware Description Languages (HDL)

  • Answer aloud, timed: Explain the process of writing a state machine in Verilog or VHDL and how to prevent race conditions during state transitions.
  • Answer aloud, timed: How do you handle clock domain crossing in a multi-clock FPGA design?

Deliverable: Spoken answers to 2 reported Embedded Systems & Hardware Description Languages (HDL) question(s), under time.

Day 6 — Answer out loud: Board Layout & Hardware Co-Design

  • Answer aloud, timed: During a board layout review, what critical steps do you take to isolate sensitive analog control lines from high-noise switching components?
  • Answer aloud, timed: How does parasitic inductance in a PCB layout affect the switching characteristics of power MOSFETs, and how do you compensate for this in software?

Deliverable: Spoken answers to 2 reported Board Layout & Hardware Co-Design question(s), under time.

Day 7 — Answer out loud: Power Electronics & Control Systems Principles

  • Answer aloud, timed: Explain the difference between scalar control (V/Hz) and vector control (Field Oriented Control) in AC induction motors.
  • Answer aloud, timed: How do you mathematically model and tune a PID controller for a system with significant thermal inertia?

Deliverable: Spoken answers to 2 reported Power Electronics & Control Systems Principles question(s), under time.

Behavioural preparation

Behavioural rounds judge the decision you made and what it cost.

How do you handle anti-windup in an integral controller when the actuator reaches saturation?

Medium · Power Electronics & Control Systems Prin

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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 time you disagreed with a hardware engineer regarding whether a system failure was caused by a soft

Medium · Behavioral & Engineering Philosophy

Describe a time you disagreed with a hardware engineer regarding whether a system failure was caused by a software bug or a physical component defect. How did you resolve it?

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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 complex technical problem you solved where you had to rely purely on first-principles physics

Medium · Behavioral & Engineering Philosophy

Tell me about a complex technical problem you solved where you had to rely purely on first-principles physics rather than documentation or standard procedures.

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. 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?