The C4 Model: Visualizing Software Architecture • Simon Brown & Susanne Kaiser • GOTO 2026

This interview was recorded for the GOTO Book Club. #GOTOcon #GOTObookclub http://gotopia.tech/bookclub Check out more here: https://gotopia.tech/episodes/449 Simon Brown - Author & Creator of "The C4 Model" @simonbrown4821 Susanne Kaiser - Independent Tech Consultant & Author of "Architecture for Flow" @architectureforflow RESOURCES Simon https://simonbrown.je https://bsky.app/profile/simonbrown.je https://twitter.com/simonbrown https://linkedin.com/in/simonbrownjersey https://c4model.com Susanne https://bsky.app/profile/suksr.bsky.social https://mastodon.social/@suksr https://www.linkedin.com/in/susannekaiser1 https://susannekaiser.net Links https://structurizr.com https://youtu.be/3Gc5pN9sGzw https://youtu.be/5OjqD-ow8GE https://youtu.be/NwtE82Wzs_U https://youtu.be/b8WI1QYP0Zk https://youtu.be/Za1-v4Zkq5E https://youtu.be/FqTL-_tLf6I DESCRIPTION Simon Brown explains that the C4 Model started not as a grand design theory, but as a practical answer to an embarrassing problem: running a workshop on architecture diagramming, he realized he couldn't understand any of the diagrams being produced. The model formalized his own consulting practice of hierarchical handover documentation — context diagram at the top, containers below, components and code at the bottom — giving it a name and making it teachable. His core advice is to start with just the top two levels: context and container diagrams. These change infrequently, are quick to draw, and deliver immediate value. Levels three and four — components and code — are included for completeness but age rapidly with every commit, and in most cases aren't worth the maintenance overhead. Two especially practical insights emerge from the conversation. First, how to handle microservices: if your team owns all the services inside a system boundary, each service is a collection of C4 containers; if you depend on another team's service that you can't see inside, model it as an opaque software system. This maps naturally to how domain boundaries and team ownership actually work in practice. Second, the surprisingly important distinction between modeling and diagramming: C4's real value is the shared vocabulary — systems, containers, components, code — not the visual notation itself. Teams using entirely different tooling can communicate clearly because they've agreed on what the words mean. Simon is firm that there will be no C4 v2; the model is intentionally lightweight, and adding more would risk turning it into the next UML — comprehensive, heavy, and largely abandoned. TIMECODES 00:00 Intro 00:57 What problem Does the C4 Model solve? 02:04 The origin story: From workshop chaos to C4 Model 04:34 The 4 levels — And why you probably only need 2 07:03 Containers 07:44 Should architecture diagrams show technology? 09:51 How to get started with the C4 Model 19:23 How to model microservices in C4 21:55 Where does C4 not work? 24:07 What's the 1 thing to take away from the book? 26:15 Outro RECOMMENDED BOOKS Simon Brown • The C4 Model • https://amzn.to/4xB9V33 Susanne Kaiser • Adaptive Systems With Domain-Driven Design, Wardley Mapping & Team Topologies • https://amzn.to/3XTmNCc Nick Rozanski &, Eóin Woods • Software Systems Architecture • https://amzn.to/4cOLtTv van Kelle, Verschatse &Baas-Schwegler • Collaborative Software Design • https://amzn.to/4iv0N8I https://bsky.app/profile/gotocon.com https://twitter.com/GOTOcon https://www.linkedin.com/company/goto- https://www.instagram.com/goto_con https://www.facebook.com/GOTOConferences #SoftwareArchitecture #C4Model #Sturcturizr #Monolith #ModularMonolith #Microservices #UML #DDD #MessageDrivenArchitectures #Abstractions #Microfrontends #SimonBrown #SusanneKaiser #SoftwareEngineering #Programming #TodayInTech #BookClub CHANNEL MEMBERSHIP BONUS Join this channel to get early access to videos & other perks: https://www.youtube.com/channel/UCs_tLP3AiwYKwdUHpltJPuA/join Looking for a unique learning experience? Attend the next GOTO conference near you! Get your ticket at https://gotopia.tech Sign up for updates and specials at https://gotopia.tech/newsletter SUBSCRIBE TO OUR CHANNEL - new videos posted almost daily. https://www.youtube.com/user/GotoConferences/?sub_confirmation=1