OCI Principal TPM — Technical Round
Data Center Infrastructure Delivery · Interviewer: Louis Chia
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📅 Tue, 29 Sep 2026 · 3:00 PM SGT · 60 min · Zoom · on camera · badge ready
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Round 1 ✓
Recruiter pre-screen
Round 2 — now
Technical (elimination)
Ahead
Further rounds (4–5 total)

🎯How to answer (every time)

(1) direct answer in one line → (2) the mechanism / how you ran it → (3) one concrete example → (4) stop.
Louis is a career TPM (ex-AWS). lead with the mechanism — cadence, who owned mitigations, how you escalated — not just the headline. Frame in AWS language: working backwards, operational readiness review, correction-of-errors, mechanisms over intentions. At the edge of your knowledge: say what you know, how you'd close the gap, who you'd pull in. Never bluff.

🧭Who you're facing — Louis Chia

1. Program rigor over name-dropping. He'll ask how you ran the risk register, not just that you had one.
2. Use the shared AWS DNA. Anchor your zero-downtime record as a mechanism you built, not luck.
3. Calm honesty at the edge scores high with someone who's held the seat. bluffing fails hardest here.

Source: contact-data aggregator — directional, not confirmed.

⭐Chirag's 6 questions → your story

Facts unchanged. framing is now a TPM's. gold terms are the ones Louis will recognize.

A failure & how you handled it
During integrated systems testing, the direct-to-chip loop failed its minimum test. I took single-threaded ownership and ran it as a correction-of-errors: root cause was water quality, construction debris in the loop. Real output was the mechanism — water-quality verification is now a standing acceptance gate in the commissioning ORR, so it can't recur.
RCA → permanent gate
LP: Dive Deep · Ownership · Highest Standards · Earn Trust
A success
Treated it as a two-way-door experiment, reversible, so we moved fast. Set the input metric I controlled, supply temp 25 → 27 across two 4.5 MW halls, measured the output metric, PUE. Landed 1.34, cited by IMDA at the Tropical DC Standard launch.
PUE 1.34 · cited by IMDA
LP: Deliver Results · Invent & Simplify · Earn Trust
Delivery was delayed & recovery
On the integrated master schedule, network move-in was gated by cable-tray completion, and it slipped. I called it a critical-path dependency, not a parallel task, escalated early with impact and options, re-sequenced around the real constraint, protected the cutover.
Go-live milestone held
LP: Bias for Action · Dive Deep · Deliver Results
Risk assessment / management
I run an active RAID log: each risk gets probability, impact, proximity, the milestone it threatens, an owner, a response with a fallback. Live halls beside active construction was high-proximity — whole-building view, ingress/access controls, sequencing, escalated the residual with the specific decision needed.
Zero contamination / safety incidents
LP: Ownership · Dive Deep · Earn Trust
Largest infrastructure project & your role
80 MW Malaysia campus, buildings A–D staged. Single-threaded owner from design reviews to handover. Working backwards from the readiness date, built the master schedule, managed long-lead procurement so the BOM never became the critical path, stood up the team from zero with RACI-clear roles.
80 MW campus · team from zero
LP: Ownership · Think Big · Hire & Develop · Deliver Results
How many projects at once
Up to 20 MW concurrent. two buildings rising together + a third where the hall was ready before the shell. Ran them as one portfolio against a single master schedule, allocated scarce resources by critical path and safety, held a separate operational-readiness review before each go-live.
20 MW under concurrent build
LP: Deliver Results · Dive Deep · Frugality

🗣️TPM language to weave in

Louis is ex-AWS — speak his OS. Three or four terms per answer, naturally. never use one you can't unpack.

Schedule & delivery
integrated master schedule (IMS) · critical path · dependency (vs parallel task) · gating · working backwards · cutover / go-live · input metric vs output metric
Ownership & decisions
single-threaded owner (STO) · RACI · DACI (for a decision) · two-way-door vs one-way-door (reversible = decide fast)
Risk & governance
RAID log · risk register (probability / impact / proximity) · escalation path · blameless postmortem
Amazon mechanisms (highest value)
COE = correction of errors, your RCA in his words · ORR = operational readiness review, your commissioning/handover gates · Mechanism = a process that enforces the fix so it doesn't rely on anyone remembering
Leadership principles to demonstrate
Ownership · Dive Deep · Deliver Results · Bias for Action · Insist on the Highest Standards · Earn Trust · Have Backbone, Disagree & Commit

🔧Technical domains — tap to open

1 · End-to-end delivery lifecycle +
"Walk me from lease signing to handover to operations. Where does it go wrong?"
Own the outcome across the full lifecycle: requirements & site selection → lease → design & reviews → construction → procurement → install (rack, network, cabling) → commissioning & SAT → acceptance → operational handover. It goes wrong at the seams between workstreams (tray not ready for network move-in; late access constraints; "complete" but not clean). Pull risks forward into design reviews; manage dependencies, not just boxes.
2 · Commissioning & acceptance +
"Walk me through commissioning. What does 'operationally ready' mean?"
Levelled: L1 FAT (pre-ship) → L2 delivery/component verification → L3 pre-functional/static → L4 functional performance → L5 integrated systems test (IST) — whole plant under load with failure & black-building / pull-the-plug tests. Operationally ready = passed IST + clean handover docs, MOP/SOP/runbooks, spares and trained ops.
3 · Power train & redundancy +
"Describe the power path from utility to rack, and redundancy."
Utility → MV switchgear → transformers → LV switchgear → UPS → PDU/RPP → busway/whips → rack PDU. Backup: standby gensets with ATS; dual-corded loads behind STS. Redundancy tiers: N, N+1, 2N. know which the design targets and why.
4 · Cooling (your strongest area) +
"How do you approach cooling? Experience with liquid cooling?"
Air: chilled water to CRAHs (or DX CRACs), hot/cold-aisle containment, economization where climate allows (hard in the tropics — why the Tropical DC Standard work mattered). High density (GPU/AI): direct-to-chip cold plates via a CDU isolating the IT loop from facility water; or immersion (single/two-phase). Your proof: 25→27 °C, PUE 1.34.
5 · Capacity & density +
"How do you think about rack density and capacity planning?"
Density = kW/rack, drives floor, power topology and cooling. Legacy 5–15 kW; AI/GPU 40–100+ kW → liquid not optional. Your 50 MW / 1,000+ racks = high-density GPU. Planning = match committed IT load to power & cooling headroom, stage building by building, forecast BOM & long-lead so procurement isn't the critical path.
6 · Network physical infra & cabling +
"How do you handle the network and cabling side?"
Physical network gates everything — no connectivity, no server bring-up — so it's a critical-path dependency. Structured cabling (copper/fibre/bulk), MMR/MDA layout, tray & pathways ahead of gear, clean labeling, ISP/circuits on time. You've lived the tray-vs-move-in failure and re-sequenced it. Your Pacnet/Telstra roots mean you read this layer fluently.
7 · Vendor, colocation / BTS & budget +
"How do you manage colo/vendor partners and the budget?"
Hyperscale runs through partners (colo, BTS, LV/fit-out) → lead by governance & accountability, not direct authority. Lock design before contracting, clean handoffs, manage fit-out & LV through commissioning. Own vendor selection/negotiation/governance, BOM & capacity forecasting, cost control & change management. Catch scope gaps early — a design gap costs a fraction of a handover gap.
8 · Risk management +
"How do you manage risk on a build? Give an example."
Active risk register: probability, impact, proximity, which milestone it threatens → owner + defined response (mitigate, with fallback for anything material). Escalate early with impact + options + the specific decision needed. Example: live halls beside active construction → whole-building view, ingress/access controls, deployment sequencing & safety plan → no contamination or safety incident.

✅Rehearsal tracker

🔒Lock before you speak

  • Say APAC, not APEC.
  • 50+ MW = Singapore · 80 MW = Malaysia · 20 MW concurrent.
  • 50 MW / 1,000+ racks = high-density GPU/AI. own it.
  • 15 yrs hands-on + CDCMP/CDFOM/CDCS, PMP in progress. don't volunteer "not an engineer."

❓Ask Louis

  • Biggest delivery constraint in the region right now — power, land, or talent?
  • How does OCI run operational-readiness reviews and correction-of-errors?
  • What separates a good Principal TPM from a great one on your team?

Prep hub for Bernard Tay · built for the OCI Principal TPM technical round · bernardtay.work