🎓 GM Interview Prep — both applied roles

TS Battery State Estimation (JR-202611969) + Sr Sub-System Lead Engineer, HV Battery Mgmt (JR-202612558) · built 2026-07-07 · companion to GM applications

0. The 30-second frame (say this, in your words)

"I spent 10+ years at GM on battery / EV validation — I know the systems, the process, and the people. What's different now is that I ship working software fast using AI: data pipelines, validation automation, analysis tooling. I'm a senior engineer who closes the loop from requirement to running code, not just spec." Two anchors carry every answer: deep GM battery/validation credibility + AI-accelerated delivery.

1. Role A — Technical Specialist, Battery State Estimation

JR-202611969 · Milford MI · hybrid 3x/week · senior IC

Owns SOC / SOH / SOP state estimation for HV battery systems: estimation algorithms + embedded implementation + validation + the battery data pipeline/analytics.

Quals mapping (point-by-point)

Role needsSam brings
HV battery domain (SOC/SOH/SOP)10+ yr GM battery/EV validation — lived the failure modes, cell behavior, aging, thermal. Estimation targets are the numbers you already validated against.
Algorithm developmentMS EE + DFSS Blackbelt = the math/stats spine (state estimation is Kalman-filter / model-based; DOE + variance reduction is your language).
Validation + correlationCore strength — you built/ran the validation that estimation algorithms get graded against. You know what "good" looks like on real hardware.
Battery data pipeline + analyticsAI-accelerated data tooling is your edge (see below) — ingest, clean, feature-extract, dashboard test data fast.
Embedded C/C++ (required)Lighter spot — honest framing below.
AI differentiator (concrete, judgment-forward — NOT "I use AI a lot"):
C/C++ embedded gap — honest framing (don't hide it, don't apologize):

Likely questions + answer bullets (Role A)

1. Walk me through how you'd validate an SOC estimation algorithm.
define truth reference (coulomb counting + reference cell tests) → test matrix across temp/SOC/current/aging → error metrics (RMSE, worst-case, drift over cycle) → edge cases (cold, high-rate, near-empty) → correlate model vs hardware → sign-off criteria. Tie to real GM validation you ran.
2. SOH is drifting in the field but not in the lab. How do you chase it?
data-first: pull field vs lab data, segment by usage/temp/age → hypothesize (cell aging model gap, sensor bias, unmodeled load) → reproduce in a targeted test → isolate. Emphasize the data-pipeline speed you bring.
3. How do you think about SOC vs SOH vs SOP — where do they conflict?
SOC = energy now; SOH = capacity/resistance vs new; SOP = instantaneous power limit (temp + SOC + aging dependent). Conflict: SOP must be conservative as SOH degrades to protect the pack; over-conservatism costs performance. It's a validated trade-off, not a formula.
4. Tell me about a hard battery problem you owned end to end.
SAM-FILL a real GM story — STAR: Situation, Task, Action (what YOU did), Result (number). Pick one with a measurable outcome.
5. How would you use AI/ML in this role responsibly?
ML for pattern/anomaly detection + data-driven aging models; AI for tooling/automation. Guardrail: physics-based models stay authoritative for safety-critical limits; ML augments, doesn't replace validated safety logic. Shows judgment, not hype.
6. You're light on production C/C++. Why you?
Use the honest-framing bullets above.
7. Describe your validation-to-requirements discipline.
DFSS mindset: requirement → measurable spec → test that proves it → traceability. You've done DFMEA + DOE; you validate against intent, not just pass/fail.
8. How do you work with the embedded + controls teams?
Hand off a validated reference model + clear acceptance criteria; stay in the loop through bring-up; translate between physics/algorithm and code. Senior IC glue.
9. Why come back to GM (and via a gap)?
Honest + forward: built an independent services business (real shipped software + trades), sharpened AI-accelerated delivery, and want to bring that back to the battery problems you know at GM scale. Eligible again as of 7/1.
10. Where do you want to grow?
Deeper on production embedded + estimation algorithm ownership; long-term technical leadership on battery software.

2. Role B — Senior Sub-System Lead Engineer, HV Battery Management

JR-202612558 · Milford MI · hybrid 3x/week · senior IC across the full lifecycle

Owns a battery-management sub-system across the V: requirements (Requirements-First / BDD / Given-When-Then), SSTS/BTS, DFMEA, MBSE, agile/Scrum, embedded controls + calibration.

Quals mapping (point-by-point)

Role needs (req/preferred)Sam brings
SAFe / agile (PREFERRED)SAFe 5 certified — lead with this; it's an explicit preferred qual. You've run cadence/PI-style delivery.
Requirements-First / BDD / Given-When-ThenMatches how you already work — requirements rigor + acceptance criteria. Frame validation as executable requirements.
SSTS / BTS documents, traceabilityGM systems + validation background = you've authored/consumed sub-system technical specs and traced them to test.
DFMEADFSS Blackbelt — DFMEA is core toolkit; you've led risk analyses.
MBSESystems-thinking + your validation modeling; ramp on the specific toolchain.
Embedded controls + calibrationCalibration/controls experience + validation; safety-critical / ISO 26262 familiarity (preferred qual you hit).
AI differentiator (framed for a systems-lead role):

Likely questions + answer bullets (Role B)

1. How do you take a battery sub-system from requirements to validated delivery?
Requirements-first (SSTS) → decompose to testable specs (BDD/GWT) → DFMEA to surface risk → design + calibration → validation traced to each requirement → sign-off. Walk the V.
2. Give an example of leading a sub-system across teams.
SAM-FILL a GM story — cross-functional (hardware/controls/validation), your leadership, the outcome.
3. How do you run DFMEA and act on it?
Structured severity/occurrence/detection, prioritize by RPM/AP, drive detection/mitigation into design + test, close the loop. DFSS discipline.
4. How does SAFe/agile work for safety-critical embedded?
Cadence + backlog + PI planning for flow; but safety artifacts (requirements, DFMEA, ISO 26262 work products) stay rigorous — agile organizes the work, it doesn't skip the safety case.
5. Requirements-First / BDD — what does that mean to you in practice?
Write the acceptance scenario (Given-When-Then) before the design; it defines "done" and becomes the test. Prevents scope drift + makes traceability automatic.
6. Walk me through a calibration problem you solved.
SAM-FILL — controls/cal example; method + validation + result.
7. How do you handle a requirement conflict between sub-systems?
Surface early via interface specs + MBSE model; quantify the trade; escalate with data + a recommendation, not just the conflict.
8. ISO 26262 — how have you touched functional safety?
Frame your real exposure honestly (safety-critical validation, FMEA, requirements traceability); note it's a preferred (not required) qual and you're ramping the formal work-products.
9. Why you for a senior sub-system lead seat?
Systems + validation + requirements rigor + SAFe + the AI-accelerated delivery that makes traceability + tooling actually stay current. Senior IC who ships.
10. How do you mentor / raise the team's bar?
SAM-FILL — example of leveling up peers/process; the AI-tooling you'd share.

3. Smart questions for Sam to ASK (both roles)

4. Logistics + reminders

SAM-FILL before interviews: pick + rehearse 3-4 real STAR stories (bank below) · application confirmation #s + recruiter/HM names once they reach out · whether you messaged Luke + Adam · interview dates.

5. STAR-story bank SAM + CLAUDE TO FILL

Fill 4–5 of these with real GM examples (work them with Claude). Each is reusable across many questions — a strong story bank beats memorizing answers. Format: Situation (context, 1 line) → Task (what was on you) → Action (what YOU specifically did) → Result (a NUMBER if possible). Keep each to ~60–90 seconds spoken.

Slot 1 — Validation root-cause win
A hard battery/validation problem you chased to root cause. Answers: Role A Q1/Q2/Q4, "hardest problem," "how you validate."
S: [SAM+CLAUDE] · T: [__] · A: [what you did — the method] · R: [number: error reduced, defect caught, time saved]
Slot 2 — Led a project / sub-system across teams
You owned a sub-system or program element end to end. Answers: Role B Q1/Q2/Q9, "leadership," "cross-functional."
S: [SAM+CLAUDE] · T: [__] · A: [how you led + coordinated hardware/controls/validation] · R: [shipped / milestone / outcome]
Slot 3 — DFSS / DFMEA catch
A risk your DFSS/DFMEA discipline surfaced + drove into the design/test. Answers: Role B Q3, "DFMEA," "requirements rigor."
S: [SAM+CLAUDE] · T: [__] · A: [the analysis + the mitigation you drove] · R: [failure avoided / detection improved]
Slot 4 — Data / AI-accelerated delivery
You shipped a tool/pipeline/analysis fast using AI — the differentiator, concrete. Answers: both roles' AI Qs, "why you."
S: [SAM+CLAUDE] · T: [__] · A: [what you built + how AI multiplied it; you owned correctness] · R: [time cut / capability added]
Slot 5 — Cross-functional / conflict resolved
A requirement conflict or team disagreement you resolved with data. Answers: Role B Q7, "conflict," "influence."
S: [SAM+CLAUDE] · T: [__] · A: [how you quantified the trade + drove alignment] · R: [decision made / relationship kept]
GM interview prep · 2026-07-07 · role details from the JR-202611969 + JR-202612558 postings · Sam's private page (noindex) · Same Solutions substrate.