Fractal Architecture

Why is software development so difficult? A major reason is that you spend more time reading than writing code. If you can decrease the time required to read existing code, you can increase productivity. You can decrease the time you waste reading complicated code by writing code that's easy to read - code that fits in your head. Code should fit in your head at all levels of abstraction. At the entry point, at the business logic level, and at the lowest levels of detail. This is fractal architecture - code that is organised according to that principle of self-similarity. Key to achieve fractal architecture are encapsulation, aggressive thresholds, and referential transparency. Code examples will be in C# - written in a style also readable to developers working in Java, TypeScript, C++, etc.

Design Video

 Event-Driven Architectures Done Right

Far from a controversial choice, Kafka is now a technology developers and architects are adopting with enthusiasm. And it’s often not just a good choice, but a technology enabling meaningful improvements in complex, evolvable systems that need to respond to the world in real time. But surely it's possible to do wrong! In this talk, we'll look at common mistakes in event-driven systems built on top of Kafka: -Deploying Kafka when an event-driven architecture is not the best choice. -Ignoring schema management. Events are the APIs of event-driven systems! -Writing bespoke consumers when stream processing is a better fit. -Using stream processing when you really need a database. -Trivializing the task of elastic scaling in all parts of the system. It's highly likely for medium- and large-scale systems that an event-first perspective is the most helpful one to take, but it's early days, and it's still possible to get this wrong. Come to this talk for a survey of mistakes not to make. Lecture took place on Wednesday 25th August 2021 at 13:30 in Room 1 Tim Berglund is a teacher, author, and technology leader with Confluent, where he serves as the Senior Director of Developer Advocacy. He can frequently be found at speaking at conferences in the United States and all over the world. He is the co-presenter of various training videos on topics ranging from Git to Distributed Systems to Apache Kafka. He tweets as @tlberglund, blogs very occasionally at http://timberglund.com, and lives in Littleton, CO, USA with his wife, their three children having grown up. Topics covered: -What is Event-Driven Architecture -Data Mesh Principles -Scaling -State management

Architecture Best Practices Event Sourcing Video

 Introduction to Domain Modeling

DDD Design Video

 Strategic Domain-Driven Design

If you’re a software developer or architect who wants to play a more influential role in ensuring your software systems are optimised to support business goals, then you need to learn about the benefits and techniques of modern strategic domain-driven design. Many people think that DDD is about software design patterns, but that’s only a small part, and the least important part of DDD. In fact, Eric Evans wishes he’d focused more on the strategic aspects of DDD in his famous book (Domain-Driven Design: Tackling Complexity in the Heart of Software) and pushed the tactical coding patterns to the back! Strategic domain-driven design is about truly understanding the business domain. It involves collaboratively modelling business processes using advanced modelling techniques, like Event Storming and Domain Storytelling, with domain experts on an ongoing basis. One of the core outcomes of strategic DDD is identifying cohesive modules, known as bounded context. Bounded contexts help you to create a maintainable, comprehensible codebase by isolating dependencies and delineating concepts that reference different classes of business value. In this talk, you’ll see many of the most effective bounded context design heuristics, recurring patterns in the wild, and you’ll learn how to facilitate those vital modelling sessions so you can lead the adoption of strategic DDD in your organisation.

DDD Design Video

 A Case for Outside In Design

Software architecture should enable business agility, but often it does not happen because of the mismatch between product design and software architecture. In this talk, Sandro will describe how a software design approach, focused on behavior and also driven by external interactions and business flows, can enable better collaboration between business and technology. This talk shows techniques (used in real projects) to bring product and software design together, at the same time, produce an Agile architecture that is more resilient, focused, and fully aligned to business goals.

Architecture Design Video

 ES Evolving a Pragmatic, Clean Architecture - A Craftsman's Guide

Are you in a mood for a brainstorm? Join this critical review of the major decisions taken in a typical enterprise application architecture and learn to balance pragmatism with your design goals. Find out how to do just-in-time design to keep as much use-cases as simple as possible. The core purpose of this presentation is to learn to strike a **balance between pragmatism and maintainability** in your design. Without continuous refactoring, a simple design will inevitably degenerate into a Big Ball of Mud, under the assault of the new features and bugfixes. On the other hand, very highly-factored code can burden the take-off of the development and end up freezing the mindset in some rigid 'a-priori' design. The end goal of this talk is to challenge you to rethink critically the architecture of your own systems, and seek ways to simplify it to match your actual needs, with a pragmatic mindset. "Architecture is the art of postponing decisions", said Uncle Bob. This talk takes this idea further and explains an optimal mindset about designing enterprise applications: Evolving (Continuously Refactoring) a Pragmatic (Simple), Clean (aka Onion) Architecture, aiming to provide Developer Safety™️ and Comfort™️. It’s the philosophy that Victor distilled over the past 5 years, designing and implementing 9 applications as IBM Lead Architect, and delivering trainings and advises to many other companies. You’ll learn how to break data into pieces (Fit Entities, Value Objects, Data Transfer Objects), how to keep the logic simple (Facades, Domain Services, logic extraction patterns, Mappers, AOP), layering to enforce boundaries (keeping DTOs out of your logic, Dependency Inversion Principle), and many more, all in a dynamic, interactive and extremely entertaining session.

Design Hexagonal Architecture Video

 Breaking Dependencies: The SOLID Principles

SOLID is an abbreviation for five of the most important software design principles: - (S)ingle Responsibility Principle - (O)pen-Closed Principle - (L)iskov Substitution Principle - (I)nterface Segregation Principle - (D)ependency Inversion Principle For almost two decades, these principles have proven to be a valuable set of guidelines to cope with software dependencies. Although initially introduced as guidelines for object-oriented programming, they have become a universal set of guidelines that can be used equally well for procedural, functional or generic programming. In this talk I'll recap the SOLID principles and explain why they form such a valuable set of universal design guidelines. Also, I'll go into detail about several common misconceptions.

SOLID Video

 Engineering You • Martin Thompson

What are the characteristics of a good software engineer? It's a topic many people would argue endlessly about. This is not surprising given we are effectively living in the era of software alchemy. Some of the best programmers draw on strong scientific and engineering backgrounds and combine this with craft-like coding skills in a virtuous feedback cycle. In this talk, we explore the individual practices and techniques that can help bring out the engineer in you.

Design Philosophy Video

 Django structure for scale and longevity

Why? Django is great. But as we add new features, as our dev team grows and the software needs to be stable on production, things can get quite messy. We are going to look at some common patterns, derived from experience, on how to structure your Django project for scale and longevity. What? Main topics are: Django service layer or where should business logic live? Using Django Rest Framework in a clean and repeatable way and combining it with the service layer. Testing everything that matters, without repeating ourselves in different tests. We are going to talk about when to rely on existing abstraction so it's actually helpful and when to avoid existing abstraction, and code things ourselves. The examples showed in this talk are derived from working with Django in the last 5 years on projects with: Daily production usage and production deploys. Dozens of apps. Hundreds of models and APIs. Tens of integrations working simultaneously. Teams of 5 to 10 people. Who? Key takeaways from the talk: Increased productivity when developing with Django. Deeper understanding of the software development process with Django. Demo project with everything mentioned in it. The talk is great for all levels of Django knowledge - from beginners to advanced users and teams. How The main way of getting the point across is going to be by showing regular code, talking how it can get messy and then following up with examples of improving that code. Hopefully this talk will start a lot of discussion afterwards. Breakdown of the talk: Django service layer: Fat models or fat views? Where do I put my business logic? What is a service and what goes into a service? What is a selector and what goes into a selector? General Django structure: How many apps should I have? Structuring your code so youр team can be more productive and have less conflicts. Common modules and utilities. Doing APIs with Django Rest Framework: Splitting APIs in 2 groups - "giving data" and "taking data" Using a lot of generics for "give data" When do to selectors? Using no generics for "take data" (APIView + Services) Handling errors from services Inlining serializers and avoiding serializers reuse A neat inline_serializer util Introducing general error formatting for your API Testing all of that - what should be and not be tested?

Design Django Python Video

 The Pillars of Domain-Driven Design

Domain-Driven Design is neither a method nor a technology, it is a culture, a way of thinking about the needs of the customers first and putting an emphasis on their language and human interactions. The promise of DDD is to tackle complexity in the heart of software, and the means are plentiful and can be overwhelming. There are three pillars though, on which the whole approach stands. A focus on learning, language, and empathy. With the right mindset, it becomes simple to derive good models, keep them pure and aligned with the business. Simple is not easy, but done right Domain-Driven Design transforms everything in your organization from code to culture, from agile to architecture.

DDD Event Sourcing Video