Architecture And The Agile Approach - A Contradiction? - Reloaded

Mit Softwarearchitektur werden häufig übermächtige, starre und langfristige Modelle assoziiert. Nicht zuletzt vor diesem Hintergrund wird das Thema Architektur im Umfeld agiler Methoden kritisch beäugt. Der Vortrag startet mit einer persönlichen Erfahrung zu diesem Thema – ein Architekturprojekt in einem agilen Unternehmen. Ausgehend davon wird diskutiert, welchen Stellenwert Softwarearchitekturen im agilen Umfeld besitzen und welche Ansätze existieren, um dennoch Softwarearchitekturen und deren Akzeptanz zu etablieren. Am Ende erfolgt eine Betrachtung der Rolle "Softwarearchitekt" im Kontext agiler Vorgehensmodelle.

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1. Architecture And The Agile Movement A Contradiction?
2. "Technology enthusiast, org development fanatic and strong advocate on modern leadership. Motivated by 'Y'! Love to work at @Misterspex, acting as CTO” – @devpg
3. What is Agile? ▪ Iterations ▪ Transparency ▪ Potentially shippable code ▪ Continuous improvement
4. What is architecture? "The highest level concept of a system in its environment. The architecture of a software system (at a given point in time) is its organization or structure of significant components interacting through interfaces, those components being composed of successively smaller components and interfaces." – IEEE Recommended Practice for Architectural Description, IEEE Std P1471
5. What is architecture? "In most successful software projects, the expert developers working on that project have a shared understanding of the system design. This shared understanding is called ‘architecture.’ [...] These components are usually composed of smaller components, but the architecture only includes the components and interfaces that are understood by all the developers." – Ralph Johnson
6. "Architecture is about the important stuff. Whatever that is." – Who needs an architect?, by Martin Fowler "Stuff that's hard to change later." – Neal Ford What is architecture?
7. What are the goals of architecture? ▪ Reduce cost of change ▪ Minimize impact ▪ Make it easy to understand
8. No conflict so far! :-)
9. Architecture has a bad reputation in the agile world! "I want to talk to somebody that actually writes software, not drawing hand-waver" – The frustrated architect, by Simon Brown
10. Architecture has a bad reputation in the agile world! „Der Software-Architekt ist die Vergangenheit, der Software-Experte die Zukunft.“ – Die Zukunft des Architekten in der Software-Entwicklung, by Ilker Cetinkaya
11. Architecture has a bad reputation in the agile world! Why? ▪ Ivory tower ▪ Big design/ architecture up front (BDUF/BAUF) ▪ Formal models
12. Some real world experience
13. Company ABC ▪ Monolithic legacy app ▪ More than 100 software engineers ▪ One year experience with agile methods ▪ Output doubled!
14. What should be done! Change web framework Event driven architecture Enhance dev environment Swimlanes New domain model
15. What really happened! One more web framework New business Continuous delivery R/W-split pricing One more web framework
16. Welcome to the information age! ▪ Discontinuous change ▪ Short product life cycles ▪ Continuous price declines ▪ Little customer loyalty ▪ Based on knowledge work
17. What’s wrong with ivory towers? ▪ Single responsibilty ▪ Knowledge silos ▪ Distance ▪ Overengineering ▪ Separating planning from execution
18. And what's wrong with big up front? The unknown unknown! Continuous discovery Window of opportunity
19. Evolving Architecture Emergent Design An agile approach
20. Evolving & Emergent evolve: To move in regular procession through a system. [de]: sich entwickeln emergent: emerging; coming into view or into existence; nascent; new. [de]: entstehend
21. Architecture and design
22. Spectrum of processes BDUF Cowboy hacking Some DUF EA+ED Waterfall Agile
23. What's emergent design? ... is based on: ▪ Best practice ▪ High test coverage ▪ Continuous refactoring Implement & Integrate
24. The fine line between big up front and cowboy hacking! Complexity Time Big up front Cowboy hacking Emergent design Essential complexity Accidental complexity
25. How to achieve "essential complexity" only? aka Evolving Architecture ▪ Distinguish between cross-system (marco) and system-internal (micro) concerns ▪ Focus on the objectives that currently matters ▪ Defer decisions to the last responsible moment ▪ Do research (e.g. spikes) to build up knowledge
26. Objectives change over time Ease of development Homogeneity Modularity Simplicity Scalability Decoupling Cohesion (Support for) Heterogeneity Source: Breaking the Monolith
27. Defer decisions in the future When you add it When you need it Technical debt
28. The last responsible moment Benefits of deferring the decision Cost of change
29. Who is responsible? Team? Architect? "Schlußendlich sollte es in einem agilen Team [...] das Ziel sein, auch die Aufgaben (Anm.: Architektur-Aspekte) gemeinschaftlich im Team umzusetzen." – Die Zukunft des Architekten in der Software-Entwicklung, by Ilker Cetinkaya
30. Do we really need architects? "Es muss keine Position eines Software-Architekten geben. Es muss auch niemand zwangsläufig fix die Rolle eines Software-Architekten innehaben. An irgendwem muss das Thema jedoch hängen, glaube ich." – Architekturbewusstsein verkörpern, by Ralf Westphal
31. What's the role of an architect? Architectus Reloadus Architectus Oryzus Source: Who needs an architect?
32. Best practices ▪ Decide for micro services/ SCS/ isolated small systems ▪ Community-driven architecture board … put responsibility where it can be taken over
33. Take away … ⓵ "No one is arguing against the sense of architecture, but the way it's implemented!" – @devpg
34. Take away … ⓶ "Find the fine line between big upfront and cowboy hacking to avoid technical debt!" – @devpg
35. Take away … ⓷ "Evolving your software architecture is an opportunity not all environments have. Use it!" – @devpg
36. Take away … ⓸ “Move decisions to the last responsible moment." – @devpg
37. Take away … ⓹ "If you have architects, put them in the team." – @devpg
38. Architecture And The Agile Movement A Contradiction?