Flipkart DevOps System Design & Architecture interview questions

Stateless does not mean there is no state. It means the state is not in the instance, which is what lets you kill any instance at any time. Every scaling and deployment property people want depends on that one thing.

The Indian e-commerce interview question, and autoscaling is the wrong first answer. A 10x spike arriving in seconds outruns any scaling loop, so the design has to absorb rather than scale.

The catalog is the easy half. The scored half is stampede dynamics: one hot key expiring can multiply origin load by a thousand in a second, and there are three distinct fixes.

The most rehearsed design question, which is exactly why the interesting parts are the ones blog posts skip: redirect semantics, key generation under failure, and analytics kept off the hot path.

The vocabulary question hiding real depth: which primitive replaces ORDER BY, why sharding by player is wrong, and what a 45,000 updates-per-second storm actually costs.

Two contracts in one system: an OTP with a 30-second promise and a sale announcement reaching fifty million phones without burning providers. Priority lanes and double-layer dedup decide the grade.

Sharding buys write headroom and bills you in joins, foreign keys, and every future migration. The key choice is a query-pattern bet; the resharding choreography separates operators from diagram artists.

Type-ahead is a latency budget wearing a search costume: keystrokes arrive every 200 milliseconds, so anything slower feels broken. Prefix indexes, freshness tiers, and typo tolerance are the scored parts.

Everyone sizes a metrics system by samples per second and everyone is wrong. The constraint that actually kills these platforms is a single label added on a Friday.

Size stored sessions from expiry and creation rates, then decide how quickly logout must take effect and what failover may forget.

Dual-writing from application code is the answer that fails quietly six months in. Change data capture, per-entity ordering, and a reindex you could run on a Tuesday are what interviewers score.

Ladders and player logic are the warm-up. Cache topology, egress arithmetic, and knowing which quality metric actually predicts churn are what separate the answers.

Trace a retry through the broker, database and external provider. The guarantee changes at each boundary, and a recorded intent does not prove a payment or email completed.

Queue time and build time are separate problems with separate fixes, and most teams spend a quarter optimising the one that is not hurting. Size the fleet from arrival rate, then attack the build with caching and graph awareness.

The design round where the honest answer is mostly about data. Stateless traffic across regions is straightforward; the database is where active-active is either solved or pretended.

The Google-style NALSD round in miniature. The boxes are easy; what is being scored is whether the numbers fall out of Little's law before you draw them.

Drawing an agent that polls a server is the easy third. The interview is about partial applies, fleet-versus-world state, and why rollback must be a pointer flip, never a reverse edit.

It converts a synchronous failure into a delay. That is the whole benefit and the whole cost, because the caller now gets an answer before the work has happened and somebody has to tell them when it did.

The classic napkin-math question. The number in the prompt is the question. Drawing the architecture before doing the arithmetic produces a design the physics forbids, and the arithmetic takes a minute.

The migration question, and the trap is answering with a target architecture. What is being scored is sequencing: how you get there without a rewrite and without a release freeze.