Once upon a time, software was simple. You built a website, connected it to a database, and you were done. Then customers started asking for APIs, mobile apps, notification emails, realtime chat… Today, cloud hosting lets us build “elastic” systems – websites that automatically scale up to handle demand; message queues and publish/subscribe patterns to handle spikes in traffic and workload without impacting your end users.

If you’re just starting out with distributed systems design, the possibilities can be overwhelming. APIs, message queueing, REST, GraphQL, gRPC… what should you choose, how does it work, how do you get started?

This workshop gives you a hands-on introduction to the most important messaging patterns used in modern application development. Using C# and .NET, we’ll build a series of small example apps and services, wire them together using these patterns, and discuss how – and when – you’d apply the same patterns in your own applications.

Course Structure and Contents

Introduction

• What are “distributed systems”?
• Monoliths and microservices
• Common integration patterns
• Principles of distributed architecture

Connecting Components using HTTP

• HTTP architectural patterns – XMLRPC, REST, GraphQL
• Designing HTTP APIs
• HTTP frameworks: WebAPI, NancyFX, ServiceStack
• Working with HTTP APIs: testing and tooling
• Scaling HTTP APIs: caching strategies
• Exercise: building an HTTP API client and server

Message queues and pub/sub

• Principles of message queues
• Message queueing in .NET – Redis, MSMQ, EasyNetQ
• Queueing strategies and error handling
• Advanced architectural patterns: CQRS, event sourcing
• Exercise: building a pub/sub system using .NET

Protocol Buffers and gRPC

• History of RPC on .NET – SOAP, DISCO, WSDL, WCF
• Introduction to Protocol Buffers
• Contract-first development
• Advantages of gRPC
• Exercise: high-performance architecture using gRPC

Connecting to the Web

• Integrating browsers with distributed systems
• The “Backends for Frontends” pattern
• Working with SignalR
• Exercise: real-time browser notifications using SignalR

Target Audience and Prerequisites

This workshop is aimed at developers with some experience writing applications using C# and Microsoft .NET.

Attendees will be writing and running .NET code during the workshop, so will need a computer running Windows, macOS or Linux, and ideally install the Microsoft .NET SDK from https://dotnet.microsoft.com/download.

Exercises can be done in .NET Framework 4.6+ or .NET Core 2.0+