Instacart Coding & Algorithms interview questions focus on practical problem solving, clear implementation, and communication under time pressure. What’s distinctive is the company’s frequent use of platform-based screens (CodeSignal/HackerRank) and multi-part coding problems where later parts build on earlier work; interviewers often look for readable, testable code and an ability to iterate when requirements change. Expect 45–60 minute coding rounds (usually two), with system-design and behavioral rounds for senior roles. Interviewers evaluate correctness, time/space complexity reasoning, debugging, and trade-off awareness as much as raw algorithmic cleverness. For effective interview preparation, practice timed, language-idiomatic solutions to common data-structure patterns (arrays, strings, trees/graphs, hashing, heaps, two-pointers, and DP) and rehearse explaining complexity and edge cases aloud. Work on writing modular, well-tested code and doing end-to-end runs in a CodeSignal-like environment. Do at least a few full mock interviews that mirror the multi-step format you may face, and be prepared to discuss trade-offs and concise optimizations during follow-up questions.