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Home Depot senior / L5 system design interview: what to expect in 2026

backend_bekah · 5 replies

got asked to write this up after a few DMs. went through the senior SWE (which they call something like Staff/Senior depending on team) system design round at Home Depot in spring 2026. here's what i know.

first, their system design interview is retail-domain-aware. you're not designing abstract generic systems. the prompt i got was roughly: design the order management system that handles online purchase through to store pickup (BOPIS). they really care that you understand the store-as-a-fulfillment-center model, which is core to their operational strategy.

what they looked for: walking through requirements before jumping to diagrams. they dinged someone i know who just started drawing boxes. thinking about scale: Home Depot does something like 2B+ transactions a year, so naive designs get challenged fast. resilience and failure modes. what happens when a store's inventory system goes offline during peak hours? how do you degrade gracefully? operational complexity, not just technical elegance. they want to know you've shipped something that had to actually work in the real world.

what they did NOT care about: memorized frameworks or 'typical' system design interview scripts. if you recite the 'first clarify requirements, then estimate scale, then...' script robotically they just kind of stare at you. specific tech choices. kafka vs kinesis didn't matter much. reasoning mattered.

i spent maybe 10 minutes on requirements/constraints, 30 minutes on the core design, and then 15-20 minutes being grilled on edge cases and failure scenarios. the interviewers were two staff engineers and they were both very engaged.

one thing worth knowing: Home Depot has invested heavily in their in-house platform (they call it their interconnected retail platform or something adjacent). knowing that they're not just using off-the-shelf solutions is relevant context. they want people who can work with complex, partially-legacy infrastructure.

dm me if you want to talk through the design problem specifically.

5 replies

staff_steph

the BOPIS design is such a good interview prompt for retail eng. so many interesting tradeoffs. did they want you to handle the 'oversell' problem where inventory shows available but item is actually gone?

infra_ines

yes, explicitly. i proposed a soft reserve with a TTL during checkout flow, plus a reconciliation job. they pushed on what happens when the reconciliation is delayed during a sale event. that's where the real conversation got interesting.

remote_swe_42

this matches what i saw. they care more about you having opinions and defending them than getting to the 'right' answer.

visa_vik

do they typically give you choice of topic or is it always a retail-specific scenario? asking because i have more distributed systems background than retail domain knowledge.

infra_ines

in my experience it's always retail-flavored but the underlying distributed systems concepts are the same. don't worry about not knowing Home Depot operations in detail. the fundamentals carry you, the domain details come up naturally in discussion.