Save the Date for the next SAG: November 24–27, 2025 in Berlin

THURSDAY 14 OCTOBER 2021

All times are in Berlin time zone (UTC/GMT +2)

Architecture, Babies, and Bathwater

To seasoned software architects, it sometimes seems as if our discipline is more alike to the fashion industry than we’d like, and the hype cycle might be the best-known (pseudo-)mathematical graph in our community. Is everything new really only old stuff in new disguise, or is that just old folks yelling at the cloud? How do we distinguish genuine innovation from lipstick on a pig? And will we be able to get through this keynote without even more cliché-ridden puns? Find out and join me for a look at some examples and an attempt to draw useful conclusions.

Balancing Choreography and Orchestration

These days, many teams favor loose coupling, isolation and autonomy of services and therefore typically opt for event-driven and reactive architectures, using a communication pattern known as choreography. While choreography is beneficial in some situations, it is far from the holy grail of integration. In some scenarios, it increases coupling, often accidentally and to a dangerous degree. Orchestration is a better choice for some situations, but is often bashed for introducing tight coupling. I will debunk some of these myths and show how orchestration can even reduce coupling in some situations and totally work in an asynchronous, message-driven fashion. TLDR: Choreography vs. orchestration is NOT about choosing THE right approach. In real life, you need to balance both, so it is about choosing wisely on a case-by-case basis. In order to help you with that, I will walk you through the differences and give you some concrete guidance on decision criteria, backed by examples collected in various real-life projects.

Events! Events Everywhere!

Event-driven architecture is the pattern du jour in microservices world. But there’s more to event-driven than just asynchronous communication. Let’s talk semantics – what does “event” actually mean? Spoiler: Not everybody who uses the term means the same thing. It’s all too easy to get confused when people talk about Event Sourcing, Event Streaming, Event-Carried State Transfer, Notification Events, Domain Events, Fat Events, Event Storming and possibly yet other types of events. And above all – why should you even bother with an event-driven architecture, what are the benefits? Time for a proper clean-up. Let’s start with a clear and bounded definition of events, and from there explore the patterns of using events in micro- and macro-architecture, their benefits as well as challenges. After the talk, participants will know what questions to ask if someone suggests to go event-driven, and will be able to assess the applicability of different approaches to their architectural tasks.

Domain-driven Design & Legacy: Evolution not Revolution

A clean architecture is for greenfield projects is relatively easy. However, we usually work on legacy systems and an architecture must adapt in an evolutionary manner – otherwise it will also become legacy very quickly.
This talk will show different approaches how to improve legacy systems with domain-driven design. It will focus on different techniques for introducing bounded contexts and assessing where improvements are needed. In this way, Domain-driven Design becomes possible where it is needed most – in existing systems that are often very successful and critical from a business perspective, but were originally developed with no regard to DDD.

That's Not in My Job Description

Compared to some of the IT industry’s more imaginative job descriptions, “software architect” appears to be a clear-cut role with a generally accepted set of duties and responsibilities. Upon closer inspection, however, this seems to be one of those things that everyone agrees on until one starts looking for a common consensus on the delineation of the role, tasks, and responsibilities of software architects.
For one thing, the day-to-day work of software architects is often characterized by having to fill other roles as well, such as project manager, requirements engineer, or lead programmer. On the other hand, there are organizations that actually strive for a clear differentiation between persons responsible for different architectural levels or domains. Lack of clarity about the role and responsibilities of software architects not only leads to risks in projects and reduced job satisfaction, it also implies different expectations about the training and skill set required for architects. This presentation will explore and analyze the various perceptions of the role of software architects, based on current literature as well as feedback from practitioners and training participants. Its objective is to make an informed contribution to the ongoing debate on relevant issues, such as: What is the actual core set of tasks and responsibilities? What are typical deviations from this and what are the reasons behind them? Which consequences does this have for the work of architects, their integration into the organizational context and their training?

The Myth of Team Autonomy: Why it is an illusion and we still need it

Autonomous teams are something we often strive for in software projects. Moreover, autonomy itself is often considered a value without defining what it actually is. The talk will look at the question of team autonomy from the perspective of organisations. Can there be autonomous teams? What does autonomy mean within an organisation? Why does it happen that teams are considered as non-autonomous?
And why is the absence of autonomy still valuable? What is the connection between decisions and autonomy? And why does more autonomy inevitably lead to higher communication costs?

Why software should reflect real life

Not taking into account what a piece of software represents in real life can lead to higher complexity, additional development costs, difficult refactorings, and ultimately, a software that no longer scales.
If it gets far enough out of hand, at some point, new features cannot be implemented if they’re not compatible with the current architecture, because they would be too expensive to implement.
In this session, we’ll look at some real-life examples and at some of the things to keep in mind in order to avoid the above-mentioned issues.

Mainframe & Serverless Integration - How to Liberate the Data and Stay Competitive

Large financial institutions are at a crossroads: from the nineties, the industry invested massively in first-class reliability and resilience, but modern tech is putting pressure, pushing innovation at breakneck speed, creating a fluid transaction ecosystem, and churning out ever-evolving sets of products and tech talent. In this talk, we will cover our experience liberating the data in the mainframe with a hybrid serverless/containerized solution built on AWS. It’s an architecture with tens of Java serverless functions that live-stream mainframe data to the cloud, using a suite of services capable of operating at hundreds of rps: DynamoDB, Lambda, API Gateway, Fargate. We will do a deep dive on various integration patterns and AWS services that can be used to support them. We will dedicate a special section at performance optimizations done to reduce the cold start problems and support aggressive performance targets. In the last section, we’ll use Lake Formation to create a data platform that can enable a host of new value-add activities for the entire company.

How to read complex code?

Research shows that on average developers spend about 58 percent of their time on reading code! However, we are not explicitly taught reading code in school or in boot camps, and we rarely practice code reading too. Maybe you have never thought about it, but reading code can be confusing in many ways. Code in which you do not understand the variable names causes a different type of confusion from code that is very coupled to other code. In this talk, Felienne Hermans, associate professor at Leiden University, will firstly dive into the cognitive processes that play a role when reading code. She will then show you theories for reading code, and close the talk with some hands-on techniques that can be used to read to any piece of code with more ease and fewer headaches!

QualityStorming: Collaborative Modelling for Quality Requirements

In various communities, several methods for the collaborative modeling of business requirements have been established in recent years. Well-known examples are EventStorming or Domain Storytelling. These approaches are based on achieving a better shared understanding of the business requirements in an interdisciplinary way. But what about the requirements for the quality of the software being developed?
This is where Quality Storming comes in, trying to bring together a heterogeneous set of stakeholders of a product or project to collect quality requirements. The goal is to gain a shared understanding of the real needs for the quality characteristics of a product. To achieve this goal, Quality Storming uses some techniques from various already existing collaborative modelling approaches.
It is not the claim to produce perfectly formulated quality scenarios with the help of Quality Storming. Instead, the method aims to create a well-founded, prioritized basis for later formalization, which is understood across different stakeholder groups. The more often teams work with the technique, the better the quality of this basis becomes over time. Advanced teams are quite capable of creating very well-formulated scenarios within the framework of such a workshop.

In this talks I will introduce the workshop and the ideas behind it. You will also learn many hints for facilitating such workshops and how to proceed with the learnings generated in Quality Storming workshops.

The Art of Improving Software: Legacy Evolution, Done Right

As software developers, we spend most our time maintaining existing systems – under time and budget pressure. Building new business functionality tends to get more difficult, expensive and risky over time due to increasing size, growing complexity and lack of overview. Although we complain about technical debt, lack of innovation and the architectural deficits of historically _grown_ software, we often patch, fix or hack symptoms instead of curing the root causes of these problems. In this talk you’ll get an overview of the systematically improving or modernizing your system. The approach shown here is based upon the established idea of identifying the specific problems first, before changing or modifying a system. We will take a closer look at different areas of investigation, such as architecture, code, technology, quality requirements, application data plus development and rollout processes, in an iterative breadth-first analysis. For each area of investigation I give examples and show methodical tools for effective and practical use. Afterwards you’ll get an overview of strategical and tactical approaches to specific improvements, based upon the problems and risks found during analysis. The presentation is aimed at software development teams, architects, product owners and technical management. Everything I present in this talk has been proven in software and system projects and reviews I conducted over the last couple of years in various industries – so expect some (anonymized) practical examples!

Continuous Software Architecture for the Digital Age

Software architecture emerged in the 1990s, and has been evolving ever since, from a directive, up-front activity, where a single architect created the architecture, which was then implemented by others, to today’s team based adaptive architectural approaches where architecture is a shared activity owned by the entire team. In this talk we’ll explore the architectural practices that deliver architecture as a “shared commons” which supports the Agile+DevOps ways-of-working needed for success in the digital age.

Event-Driven Microservices - evolution, not revolution

Microservices, and especially the event-driven variants, are at the very peak of the hype cycle and, according to some, on their way down. Meanwhile, a large number of success stories and failures have been shared about this architectural style. In this session, Allard elaborates on how to achieve the benefits of Event-Driven Microservices by not focusing on the Event-Driven aspect and avoiding Microservices, to begin with. He will discuss how a different way of looking at Messaging allows a system to gradually evolve, maybe with microservices as an end result. And maybe, after all, there is something about events that drives these services…

 

Lessons Learned Using arc42 in a Real DevOps Team

In this presentation, I will talk about my experiences, successes and failures with the arc42 architecture template in a DevOps team in a corporate environment with a product development focus.
Product development is often characterized by short iteration cycles and is therefore often operated in an agile manner, as in the speaker’s team. There the existing unstructured documentation was transferred to the arc42 template and stored in a wiki. In the course of time, it turned out that tooling plays a decisive role for the quality of the documentation and therefore switched to Docs-as-Code.
In the course of the presentation, the most important decision points for the current iteration of the technical software architecture will be discussed. These include the handling of “developer prose”, outdated documentation and the architecture decisions that are particularly important for a DevOps team. The integration into the methodical procedure Kanban was made possible with arc42 and a microsite based on AsciiDoc.
Not left out are the mistakes made, such as missing quality assurance of created documentation or the mixing of business and technical topics.

Clean Infrastructure as Code

The clean code principles are well-known in modern, agile software development. But what has become the default for our business code, unfortunately by no means applies to our infrastructure code. Instead, we find badly crafted, complicated and highly tangled code that is manually tested using a trial and error approach. However, for modern cloud based systems the infrastructure code plays a crucial role. So it’s about time we being to treat it as a 1st class citizen! In this hands-on session we show several useful patterns, practices, tools and frameworks that help to write and craft clean infrastructure as code.

Modules are Underrated

Many software-developing organisations adopt DDD and apply strategic design to map out bounded contexts based on domain understanding to build services and applications within those contexts.
Teams have come to appreciate hexagonal architecture as a great approach to isolating the domain within a microservice or an application.
But that cannot be the end of the story – successful applications grow, people learn and the world changes. Bounded contexts will require adjustment, be split or abandoned – and that requires modularity within their domain cores.
I want to show an example of how hexagonal architecture and domain-driven modules go together and how such an architecture can be visualized and organized.

Software architecture in a DevOps world

Most modern software teams strive for Continuous Delivery of business impact with a DevOps mindset: you build it, you run it. With short iterations and continuous feedback loops, teams deploy new software to production daily.
But how about the role of a software architect in such a fast-paced world? With daily deployments, is there even time for software architecture? As an architect, how do you prevent being a delaying factor to the pace and success of a team? And how do you keep up?

In this session, I’ll share my experiences as a software architect in the DevOps world. I’ll talk about “just enough” architecture and moving from up front design to evolving architecture.
After this session, you’ll have practical insights and tips in how to work as an architect with a DevOps team.

Software Architecture in Predictive Analytics Software

Today it is the world of Data Science. Ample amount of data is available which when utilized at right time in right manner can help to forecast as well as predict in advance any untimely failures/disasters that can cause serious and fatal losses. Out of many, one area where such predictions and Predictive Analytics Software can be of great use is, manufacturing/process industries like power plants, oil and natural gas and many such more.

Predictive Analytics Software not only has components like main stream software-intensive systems, but it also has statistical algorithms, tools, techniques, mathematical components for pattern recognition as well as other techniques like machine learning, artificial intelligence, modelling etc. It also has diverse stakeholders and other connected systems.

Software Architecture is well practiced in main stream software-intensive systems like web, embedded, enterprise applications etc. However, Predictive Analytics being emerging branch, there is a lot of scope for research and enhancement in Software Architecture concepts with respect to such software systems.

With my experience working with Predictive Analytics Software for power plants, in this paper I will talk about following 3 points:

1. Benefits of practicing Software Architecture in Predictive Analytics Software
2. Challenges in using Software Architecture in Predictive Analytics Software
3. Future ahead

Is software architecture an end in itself?

In this session, we want to take a relaxed journey through the challenges of a software architect in everyday project life and look at different forms in which the skills of a software architect can support us – both technically and professionally – to put an executable system into production.

Some impulses and tips on further topics from the software architecture are given.

Building Greener

As a growing number of industries turn their focus on climate change, innovating in order to do their part on the journey to Net Zero – how does software engineering fit into this picture, with the industry handcuffed to it’s consumption of resources? In this talk we will dive into the various resources required to develop and host modern software, as well as the ways in which we can reduce our impact on the environment through architectural choices.

Package Structures of Software Systems

The package structure you choose has a great influence on the architecture and maintainability of your software system. It lays the foundation for whether your application remains manageable in the long term or becomes a big ball of mud. In this talk, we will show what matters.

The package structure is the basic structure of object-oriented software systems. It is not only the way of grouping classes, but also relevant for every developer in the course of their daily work. Package structures help to quickly grasp and understand structures within the application. Is it possible to derive the functionality based upon the package name and to talk about the system on the functional level? A meaningful structuring of the application helps in the daily work, in the implementation of new requirements and in maintenance. This is due the fact, that a higher implementation speed can be achieved. In many projects, the package structure is based on the stereotypes of classes such as controllers, services or factories. This technical structuring is an intuitive procedure in smaller software systems, which leads to considerable disadvantages in larger software systems like an increase of technical depts. Reasons for that are the resulting lack of system understanding which leads to unclear responsibilities, undesired dependencies, cycles and high complexity. Finally, this causes applications to erode unnoticed resulting in a reduction of productivity.

An alternative way of system decomposition helps to avoid the listed negative effects. Focusing on the mental model of the user and the developer, leads to a functional system decomposition. This will be discussed looking at use cases, which everyone can understand, and which illustrate real business transactions. 

Orthogonal Defect Classification data for improving Leading metrics

Leading indicators are the metrics providing us hint on the product quality during development cycle. Question is can we get them more accurate? we try to answer this question with Orthogonal Defect Classification (ODC) which is an important data set, that can provide insights into weak process areas of SW development, design areas requiring attention. The talk will focus on how ODC parameters can help in improving leading metrics of SW quality.

Why a Diverse Team is Crucial to Startup Success

Team diversity refers to differences between members of startup team. Those differences can include demographic differences (like age, race, sex, ethnicity), personality (extrovert, introvert, and differing Myers-Briggs types) and functional (as in skill sets, like engineering, design, copywriting, and marketing).

How does team diversity impact your customers’ experience from the moment they learn about you through their journey with you?
You will attract and relate to customers how look like you. They will understand your messaging and you will understand their needs. If you don’t represent the right dimensions of diversity, you are leaving an amazing experience behind.

Embedded Systems Architecture

Embedded Real-Time Systems, especially such with specialized hardware, pose a lot of additional architectural challenges compared to commercial software architectures: Technology trade-offs between hardware and software, qualities like availability that can only be solved in conjunction between hardware and software, hard real-time requirements, … Using an industrial system (called Traffic Pursuit System, mounted in police cars to trace traffic offenders) as an example, this talk demonstrates hardware/software-codesign and its documentation in the proven arc42 template. We will demonstrate how the template can be used to capture both, hardware and software design (and their alignment), how hardware and software interfaces can be modeled and how system design decisions can be captured.
Special emphasis will be put on demonstrating architectural decisions to fulfil specific quality requirements (like accuracy of the measurement, robustness of the overall system and ease of use for police officers).

Debunking What Makes a Great Leader

What if what we think makes a great leader is all wrong? When you ask people to think of leadership qualities, they tend to choose words like bold, powerful, and fearless. But if you ask people to name traits of the leaders they would like to emulate and/or follow; you get a different list. In fact, from my research, bold, powerful, and fearless don’t break anywhere near the top of the list. So, you have to ask yourself, are you trying to adapt the traits you think will make you a great leader or do you want to cultivate the qualities that people are looking for in a leader they want to follow? Based on my last couple of years of research across many demographics, I’ve compiled a list of qualities others look for in leaders. My message is that because you already possess the traits to be a great leader, you can unleash the power to do great things. This past year and half have presented the world with many challenges that I think we can overcome with strong, genuine leadership. Revolutions and significant changes always start with an individual. We all have a role to play and becoming a genuine leader is the start.

A Visual Language for Systems Integration

As the worlds of RESTful APIs and asynchronous events converge, it is clear that organizations struggle with understanding and designing highly-integrated, highly-distributed systems. This session will teach attendees a new, visual approach to integration design and analysis that includes synchronous APIs, asynchronous events, and other integration methods such as batch and streaming.

Retrospectives Antipatterns

Anti-Patterns are like patterns, only more informative. With anti-patterns you will first see what patterns reoccur in “bad” retrospectives and then you will see how to avoid, or remedy, the situation. Based on her experience with facilitating retrospectives, join Aino for an entertaining and informative presentation on the anti-patterns she has seen and how to overcome the problems. This talk is focused on retrospectives, but will be interesting for everyone facilitating any kind of meeting.

 

Cloud Security Beyond Technology – Organizational Challenges On The Way to Cloud Native

Many companies focus on technological questions when transitioning from traditional IT infrastructure to cloud computing. Yet, not all practices, processes, and policies fit cloud-related concepts like DevOps, DevSecOps, PaaS and serverless, zero-trust networking, etc. In this session, Rainer Stropek shares his views on organizational aspects that are crucial for larger organizations that want to benefit from cloud-native software development in hyper-scale public cloud environments.

The lost art of software design

“Big design up front is dumb. Doing no design up front is even dumber.” This quote epitomises what I’ve seen during our journey from “big design up front” in the 20th century, to “emergent design” and “evolutionary architecture” in the 21st. In their desire to become “agile”, many teams seem to have abandoned architectural thinking, up front design, documentation, diagramming, and modelling. In many cases this is a knee-jerk reaction to the heavy bloated processes of times past, and in others it’s a misinterpretation and misapplication of the agile manifesto. As a result, many of the software design activities I witness these days are very high-level and superficial in nature. The resulting output, typically an ad hoc sketch on a whiteboard, is usually ambiguous and open to interpretation, leading to a situation where the underlying solution can’t be communicated, assessed, or reviewed. If you’re willing to consider that up front design is about creating a sufficient starting point, rather than creating a perfect end-state, you soon realise that a large amount of the costly rework and “refactoring” seen on many software development teams can be avoided. Join me for a discussion about the lost art of software design, and how we can reintroduce it to help teams scale and move faster.

Evolutionary Architecture: Principles and Patterns

Evolutionary Architecture is a natural culmination of both the maturing of Agile software development and the increasing role of patterns in architecture. This talk will describe the evolution of evolutionary architecture, examining the role of patterns, I will then review the various principles of evolutionary architecture, focusing on the integration of these principles into enterprise systems.

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