Coders Crushby Napplied AI
HARDBackend Engineer

Design a DNS Server

Build a DNS resolver with recursive resolution, zone file management, caching, and TTL-based invalidation

Estimated Time: 150 minutes

Solution Overview

DNS implements hierarchical name resolution. Recursive resolvers query root, TLD, and authoritative servers. Zone files store DNS records. LRU caching with TTL reduces queries. DNSSEC adds cryptographic validation.

Architecture Pattern

Hierarchical DNS resolution with caching and zone files

Key Concepts

Recursive ResolutionZone FilesTTL CachingDNS Record TypesDNSSEC

Used By Companies

CloudflareGoogle DNSAWS Route53

Learn Implementation Details

Explore a complete guide for building this system from scratch with step-by-step tutorials:

Solution Overview

DNS implements hierarchical name resolution. Recursive resolvers query root, TLD, and authoritative servers. Zone files store DNS records. LRU caching with TTL reduces queries. DNSSEC adds cryptographic validation.

Companies
  • •Cloudflare
  • •Google DNS
  • •AWS Route53
Key Concepts
  • •Recursive Resolution
  • •Zone Files
  • •TTL Caching
  • •DNS Record Types
  • •DNSSEC
Implementation Url

https://github.com/codecrafters-io/build-your-own-x#build-your-own-dns

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