Archlify LogoArchlify
ChallengesTrails
Sign upSign in

System Design Challenges

Choose a challenge and prove your architecture skills

Browse freely. You can draw without an account; we only ask you to sign up when you want your score.

Create free account →

26 micro-challenges · 5 min

One concept per exercise. The fastest way to start.

27 full challenges

Full interview-style system design, from junior to staff.

MICRO · build the skill

Single-concept, 5-minute exercises. Build your skills one piece at a time.

Start here•5 min

Add a Cache-Aside Layer

Pick a micro to practice a single concept in 5 minutes.

5 min•Caching

Add a Write-Through Cache

5 min•Scalability

Scale an API Horizontally

5 min•Asynchrony

Decouple Services with a Message Queue

5 min•Asynchrony

Add a Dead Letter Queue

5 min•Asynchrony

Fan Out an Event to Multiple Services

5 min•API Design

Add Rate Limiting to a Public API

5 min•Observability

Add Distributed Tracing

5 min•Security

Replace Body-Supplied Identity with JWT

5 min•Scalability

Make Sessions Stateless for Horizontal Scaling

5 min•Data Modeling

Move BLOBs to Object Storage

5 min•Data Modeling

Separate OLTP and OLAP Stores

5 min•API Design

Introduce an API Gateway

5 min•Reliability

Add a Failover Replica

5 min•Scalability

Shard a Hot Database

5 min•Scalability

Scale Reads with Replicas

5 min•Performance

Offload Static Assets to a CDN

5 min•Decoupling

Break a Shared Database

5 min•Reliability

Coordinate a Distributed Transaction

5 min•Observability

Aggregate Logs & Metrics

5 min•Security

Protect a Public API at the Edge

5 min•Scalability

Go Multi-Region

5 min•API Design

Replace Polling with Push

5 min•Data Modeling

Event-Source the Write Path

5 min•Distributed Systems

Leader Election with a Coordination Service

5 min•Observability

Metrics Collection and Alerting

Micros train one concept in 5 min; challenges bring it all together in a real problem.

CHALLENGES · prove the skill

Sort by:
Tags:

27 challenges

Junior30 min

Design a URL Shortener

API Design

HashingKey-Value StoreREST API
Junior30 min

Design a Paste Service

Storage Systems

Object StorageTTLREST API
Junior25 min

Design a Link-in-Bio Service

API Design

CRUD APICachingSlugs+1
Junior25 min

Design an Image Resizing Service

Storage Systems

Object StorageAsync ProcessingCDN+1
Junior30 min

Design a Log Collection Agent

Data Pipelines

Log IngestionAppend-OnlyBuffering+1
Mid-Level50 min

Design a Notification System

Real-Time Systems

Push NotificationsEvent-DrivenMessage Queues+1
Mid-Level45 min

Design a Distributed Job Scheduler

Distributed Systems

CronDistributed LockingAt-Least-Once+1
Mid-Level45 min

Design a Feature Flag Service

Distributed Systems

ConfigurationGradual RolloutTargeting+1
Mid-Level50 min

Design a Metrics Storage System

Data Pipelines

Time-SeriesCompressionAggregation+1
Mid-Level45 min

Design a Product Catalog Service

Search Systems

Faceted SearchCachingInventory+1
Mid-Level45 min

Design a Geolocation Service

Location Services

GeospatialIP LookupProximity+1
Mid-Level50 min

Design a File Sharing Service

Storage Systems

Object StorageCDNPresigned URLs+1
Mid-Level55 min

Design an API Gateway

Distributed Systems

Reverse ProxyRoutingAuth+2
Senior65 min

Design an ML Feature Store

Data Pipelines

Feature EngineeringPoint-in-Time CorrectnessLow-Latency
Senior65 min

Design an Event Sourcing / CQRS System

Distributed Systems

Event SourcingCQRSProjections+2
Senior60 min

Design a Multi-Tenant SaaS Platform

SaaS Architecture

Multi-TenancyData IsolationRBAC+2
Senior70 min

Design a Collaborative Text Editor

Real-Time Systems

CRDTOperational TransformWebSockets+1
Senior60 min

Design a Ticket Sale Launch

Scalability

TicketingTraffic SpikesQueues+3
Senior60 min

Design a Distributed Config Management Service

Distributed Systems

ConsistencyWatch APIVersioning+1
Senior60 min

Design an Audit Log System

Data Pipelines

Append-OnlyTamper-ProofCompliance+2
Senior65 min

Design a Service Mesh

Distributed Systems

Sidecar ProxymTLSCircuit Breaker+1
Senior65 min

Design a Distributed Search Engine

Search Systems

Inverted IndexShardingBM25 Ranking+1
Staff+80 min

Design a Data Lake Platform

Data Pipelines

LakehousePartitioningSchema Evolution+2
Staff+85 min

Design a Distributed Key-Value Store

Distributed Systems

Consistent HashingQuorumGossip Protocol+1
Staff+80 min

Design a Global Identity and Access Management System

Distributed Systems

RBACABACPolicy Evaluation+2
Staff+80 min

Design a Secret Management Service

Distributed Systems

EncryptionKey ManagementAudit+2
Staff+85 min

Design a Multi-Region Database

Distributed Systems

Multi-MasterConflict ResolutionCRDT+2