+9Design a rate limiterSystem designDesign a service that limits how many requests each API client can make. It sits in front of every API endpoint at high traffic.
Reported by 1 member · Last asked Oct 2026
#distributed systems
- +9
Distributed mode and median across worker shardsCodingYou are given a cluster of k worker nodes, numbered 0 to k - 1. Each worker holds its own unsorted slice (shard) of a large integer dataset. A worker can read only its own shard…Last asked Sep 2026
Merge sorted arrays, then sort files too large for memoryCoding1. Merge two sorted arrays of integers into one sorted array. 2. The two inputs are now huge files that don't fit in memory. Merge them with bounded memory and buffered reads and…Last asked Sep 2026
Design a control plane for cloud clusters with host health checksSystem designDesign the management layer of a cloud platform that runs clusters of hosts (VMs or physical machines). It takes requests to create, resize and change clusters, decides which…Last asked Sep 2026
Design the metadata service of a strongly consistent distributed file systemSystem designDesign the namespace layer for a distributed file system: make directories, list them, put and get files, delete, and walk the tree recursively. A listing must reflect every write…Last asked Sep 2026
+1Count and map a cluster tree with message passingCodingA cluster of n machines is wired as a rooted tree (any number of children per node). Each machine knows only three things: its own id (a string such as "4"), its parent's id ("-1"…Last asked Sep 2026- +12Design a distributed job schedulerSystem designDesign a service that runs millions of scheduled and on-demand jobs (cron-like and one-off) reliably across a fleet of workers.Last asked Sep 2026
Recruiter screen with an AI interviewer: distributed systems experience and production debuggingBehavioralA short first screen run by an AI interviewer that asks questions quickly. Expect: 1. Your project experience with the stack in the job description (Go, Java, Spark…Last asked Sep 2026
Design an autonomous-vehicle simulatorSystem designDesign a simulation system for testing self-driving software: how scenarios are defined, how the vehicle software runs against simulated sensors and other actors, how many…Last asked Aug 2026
+4Design a distributed rate limiterSystem designDesign a rate limiter that enforces a token-bucket limit per client across a fleet of servers. Cover where the limiter sits, where the bucket state lives (a shared store, local…Last asked Aug 2026
Design an ad frequency capping serviceSystem designDesign the service that decides, at ad-serving time, whether a user may see another ad from a campaign, so that caps like "at most 3 per user per day" or "exactly once" hold…Last asked Aug 2026- Design a distributed crossword solverSystem designGiven a large crossword grid with about a hundred slots and a dictionary of around a million words, design a service that fills the grid. One machine cannot search the space fast…Last asked Aug 2026
Design a reliable job schedulerSystem designDesign a service that runs jobs at scheduled times at large scale, such as payment jobs that must run on time and exactly once in effect. Cover storing schedules, finding jobs…Last asked Aug 2026
Design a token-based rate limiter for AI agentsSystem designAI agents call paid services, and each call spends billing tokens. Design a limiter that caps how many tokens each agent or customer can spend over time, enforces the cap across…Last asked Aug 2026- Design a control plane that tracks hosts and assigns jobsSystem designDesign a central service that knows the live state of many compute hosts and hands jobs to them. Focus on how hosts and the service talk (heartbeats, push versus pull), where…Last asked Jun 2026
Design a durable cron job schedulerSystem designDesign a service that runs recurring jobs on cron-style schedules and does not lose them when machines fail. Cover how schedules are stored and turned into the next run time, how…Last asked Apr 2026
+1Web-scale crawl cleaning for pretraining dataSystem designDesign a staged batch pipeline that turns raw web crawl into a deduplicated, quality-filtered, decontaminated pretraining corpus on a fixed cluster and deadline. Reported on…Last asked Mar 2026
Debug performance problems in a distributed systemSystem designA distributed service has become slow. Walk through how you find out why: metrics, tracing and logs, finding the slow component, common causes (hot partitions, lock contention…Last asked Dec 2025
LFU cache, then distribute itCodingDesign and implement a least-frequently-used cache with get and put in O(1), evicting the least used key and, among ties, the least recently used. The input then becomes a stream…Last asked Nov 2025
Compare Paxos and RaftSystem designExplain how Paxos and Raft reach consensus and how they differ: leader election, log replication, how each handles failures and network partitions, and why Raft is considered…Last asked Sep 2025
Design a job schedulerSystem designDesign a service that runs jobs for other teams: jobs can run once, at a given time or on a recurring schedule. Cover how jobs are submitted and stored, how the scheduler finds…Last asked Sep 2025- Design a distributed counter for many usersSystem designMany users increment shared counters concurrently. Start with a correct single-process counter with locking, then design it for many servers: atomic increments in a database…Last asked Sep 2025
Guided system design fundamentals roundSystem designAn interviewer-led system design exercise covering requirements, architecture, storage, caching, async work, reliability and observability for a supplied scenario. Reported on…- Commit-to-production delivery pipelineSystem designDesign a CI/CD pipeline from commit to deployment covering source integration, builds, artifacts, quality gates, deployment and observability. Reported on 1point3acres' Baseten…
- Dense versus mixture-of-experts at fixed computeML designWith a fixed activated-parameter budget, compare a dense model against a mixture-of-experts on training cost, memory, communication, stability, inference and engineering effort…
- Design review: checkpointing a large training runAI system designYou are reviewing the checkpointing design for a month-long training run. Critique it: what fails, what it costs, what you would change, and what the doc does not cover. You have…