Microsoft Low Level Design Round Interview Questions Asked in 2026
Microsoft have introduced AI assisted Low Level Design round. This is a new unique and interactive pair-programming round split into three distinct phases. Rather than just writing code from scratch, You have to architect a system, prompt an AI model (ChatGPT/Gemini) to generate it, and then critically audit the AI's output.
Complete list of microsoft LLD round Questions:
https://codezym.com/lld/microsoft
If you are looking for Microsoft DS & Algo round questions then you can find them here:
https://codezym.com/lld/microsoft-dsa
LLD rounds are there for SDE-2. Also there may be more than one LLD rounds scheduled. Expect concurrency discussions in LLD questions like cache or configuration management service etc.
LRU cache can be asked either in DSA or LLD rounds
https://leetcode.com/problems/lru-cache/description/
Microsoft interviewers prefer asking DSA based design questions like Design LRU Cache, Design Tic-Tac-Toe, Design Google Search Autocomplete etc in their Low Level design rounds.
If you use Java then know about synchronized keyword and how you can use it to make your solution thread-safe.-
Design a Job Scheduler
Design a scheduler for a massively parallel distributed system. Machines expose capabilities, and every job may be assigned only to a machine that contains all of its required capabilities.
Support multiple assignment criteria, such as choosing the machine with the fewest unfinished jobs or the most finished jobs. Keep the selection logic extensible, update counters when a job finishes and use a deterministic lexicographical tie-breaker.
https://codezym.com/question/22-design-job-scheduler -
Design Configuration Management Service
Design a configuration-management service that keeps configuration data behind a clean interface instead of spreading configuration logic throughout the application.
Focus on modelling configuration records and operations clearly, validating state changes and keeping the service easy to extend when new configuration behavior or storage responsibilities are introduced.
https://codezym.com/question/319-config-management-service -
AI - Design an Excel-Like Autofill Engine
Design an autofill engine similar to Microsoft Excel. Given seed cell values and a requested cell count, the engine should recognize a supported series and generate the remaining values.
Support numeric progressions and character-based patterns while keeping their logic separate and extensible. Preserve important input rules such as case, negative values and valid number formatting.
https://codezym.com/question/320-excel-like-autofill-engine -
Design Document Comment Service
Design an in-memory comment service initialized with a set of document IDs. Reviewers can add comments only to existing documents and retrieve all comments for a selected document.
Preserve insertion order, reject comments for unknown documents and model documents, reviewers and comment data without adding unnecessary complexity.
https://codezym.com/question/326-document-comment-service -
Search Matching Lines in a Document
Design a document search service that returns the IDs of lines containing every word in a query. Matching is case-insensitive, words may appear in any order and each query term must match a whole word.
Support persistent line deletion while keeping original line IDs stable. Return matches in increasing ID order and choose data structures that make repeated searches and deletions easy to reason about.
https://codezym.com/question/327-search-matching-lines-in-document -
Design a Parking Lot
Design a parking lot with multiple floors and separate spaces for two-wheelers and four-wheelers. Support parking, vehicle removal, vehicle lookup by registration number or ticket ID and free-space counts.
Implement alternative allocation rules, including the globally lowest indexed compatible spot and a strategy that first chooses the floor with the most compatible free spaces. Resolve every tie deterministically.
https://codezym.com/question/7-design-a-parking-lot -
Design Vending Machine With Exact Payment
Design a vending machine that manages products, prices and available stock. A purchase succeeds only when the selected product is available and the customer provides the exact required payment.
Handle invalid selections, insufficient stock and incorrect payment amounts without corrupting inventory. Keep selection, payment validation and dispensing responsibilities cleanly separated.
https://codezym.com/question/335-vending-machine-with-exact-payment -
Design Runtime Data Source Access Layer
Design a data access layer that retrieves and updates key-value data while allowing its underlying source to change at runtime. Supported sources include a database, an API and a file, each with independent records.
Use Strategy to isolate source-specific behavior and a Factory to create the correct implementation. Business logic should use one stable interface and remain independent of the active data source.
https://codezym.com/question/338-runtime-data-source-access-layer -
Design Multi-Module Logging Framework
Design a logging framework shared by three application modules. Each accepted log contains a sequence number, module, destination, level and activity data, then enters a shared buffer before being streamed to a file or tool.
Acknowledge a log only after a successful write. Also support deterministic retrieval by destination, module, level and an inclusive sequence-number range while discussing producer-consumer coordination and thread safety.
https://codezym.com/question/340-multi-module-logging-framework -
Design Notification System
Design an in-memory notification system with supported channels such as email, SMS and push. Registered users subscribe to event types on one or more channels and may later unsubscribe.
Deliver one notification per unique user-and-channel subscription, prevent duplicates and maintain each user's inbox in delivery order. Keep returned results deterministic and make new channels easy to add.
https://codezym.com/question/133-design-notification-system -
Design an Elevator System - Request Feasibility (Single Lift)
Build the controller for a single lift that immediately accepts or rejects ride requests. Every accepted plan must respect lift capacity and guarantee that each rider reaches the destination within the allowed number of intermediate stops.
Evaluate new requests without violating promises made to existing riders. Treat upward and downward passes independently, define stop counting precisely and test overlapping routes where capacity or stop limits force rejection.
https://codezym.com/question/23-elevator-system-request-feasibility-single-lift