In this episode we talk about the relationship between software architecture and the business. Based on his book, Beyond Software Architecture we discuss how things such as branding, licensing, updating or different deployment scenarios influence the technical architecture of a system. We also discuss issues such as portability that add a huge amount of complexity, although from a business perspective it often does not make much sense. In the second part of the interview we discuss how the technical team and the business team can improve the way they work together. We look at some of the games (such as Buy a Feature or Give them a Hot Tub) from his new book Innovation Games, which discusses how to use collaborative play to be more creative and innovative in product creation.

In this Episode we talked about the new POSA 4 book which has recently been published. We talk to two of the authors, Kevlin Henney and Frank Buschmann (the third author, Doug Schmidt was not available - and he had also been on the podcast a couple of times :-)). The book contains a pattern language for distributed systems. It contains 114 patterns that had been published before by many different other authors. The patterns have been rewritten to form a consistent language. We basically talked through the different sections of the book, which gives a really good overview over the challenges and the solutions of building distributed systems. These sections include From Mud to Structure, Distribution Infrastructure, Event Demultiplexing and Dispatching, Interface Partitioning, Component Patitioning, Application Contrl, Concurrency, Synchronization, Object Interaction, Adaptazion and Extension, Modal Behaviour, Resource Management and finally, Database Access. The book references several other previous works (as listed below). Interestingly, many of these referenced works and authors have also been discussed previously on the podcast. Here are the back references: Domain Driven Design, Eric Evans Messaging Patterns, Gregor Hohpe POSA 2 Patterns, Doug Schmidt Concurrency: Part 1, Part 2, Part 3 and the interview with Goetz and Holmes Remoting Patterns Part 1 and Part 2 POSA3, Resource Management

In this Episode we talk about the Scala language with its creator Martin Odersky. Scala is a language that fuses object oriented and functional programming. Martin started out by providing a two-minute overview over the language, and then talked a little bit about its history. We then discussed the basics of functional programming. The main part of the episode features a discussion of some of the important features of the Scala language: Case Classes and Pattern Matching Multiple Inheritance and Compound Types, Traits, Mixins Closures Functions as types, "Function pointers", Anonymous functions Higher Order Functions Currying (Sequence) Comprehensions Generics Type Bounds (Upper, Lower) Static/Dynamic Typing, Type Inference Operators Implicits We then talked about Scala's actors library, a highly scalable concurrency package. The last part of the episode covered some more general topics, such as where and how Scala is used today, IDE support and the user and developer community. We concluded the episode by looking at current development and next steps in Scala language evolution.

This show takes a behind-the-scenes look at compilers and their inner workings, using the Gnu compiler collection (GCC) as an example. Arno interview Morgan Deters, covering all steps from the parsing of different programming languages to machine independenet optimizations and generating processor specific binary code.

This episode features Scrum, a very popular Agile software development framework. We interview Roman Pichler, a Certified ScrumMaster Trainer and independent consultant. Roman explains the principles behind Scrum, its roles and its key practices. He also answers FAQs. This episode continues our track on software development processes discussing an additional Agile method. Roman is currently writing a book on Scrum in German that provides more in-depth information of the topics discussed in the podcast. The book will be available in autumn 2007 published by d.punkt (Heidelberg, Germany).

This episode is a discussion with Jonathan Aldrich (Assistant Professor at CMU) about static analysis. The discussion covered theory as well as practice and tools. We started with an explanation of what static analysis actually is, which kinds of errors it can find and how it is different from testing and reviews. The core challenge of such an analysis tool is to understand the semantics of the program and reduce its possible state space to make it analysable - in effect reconstructing the programmer's intent from the code. The user can "help" the tool with this challenge by using suitable annotations; also, languages could do a better job of being analysable. The conceptual discussion was concluded by looking at the principles of static analysis (termination, soundness. precision) and how this approach relates to model analysis. The second more practical part started out with a discussion of how Microsoft successfully uses static analysis in their Windows development. We then discussed some of the tools available; these include Findbugs, Coverity, Codesonar, Clockwork, Fortify, Polyspace and Codesurfer. To conclude the discussion of tools, we discussed the commonalities and differences with architecture visualization tools as well as metrics and heuristics. Part three of the discussion briefly looked at how to introduce static analysis tools into an organization's development process and tool chain. We concluded the discussion by looking at situations where static analysis does not work, as well as at the FLUID research project at CMU.

Variability is one of the key concerns in software product line engineering. The episode introduces the concepts of structural and non-structural (or configurative) variability. It also discusses how to find and model variability, and especially how to implement variability in the solution artifacts. Michael and Markus discuss a series of variability mechanisms that can be used with today's programming languages and technologies.

This episode is about compile-time metaprogramming, and specifically, about implementing DSLs via compile-time metaprogramming. Our guest, Laurence Tratt, illustrates the idea with his (research) programming language called Converge. We started by talking about the importance of a custom syntax for DSL and took a brief look at the definition of DSLs by a chap called Paul Hudak. We then briefly covered the disctinction between internal and external DSLs. More to the point of this episode, we discussed the concept of compile-time metaprogramming, and the language features necessary to achieve it: in converge, these concepts are called splice, quasi-quote and insertion. We then looked at how the Converge compiler works, and at the additional features that are required to implement DSLs based on the metaprogramming features mentioned above. Using an example, we then walked through how to implement a simple DSL. Looking at some of the more technical details, we discussed the difference between the parse tree and the abstract syntax tree and at different kinds of parsers - specifically, the Earley parser used by Converge. In multi-stage languages (i.e. languages that execute programs and meta programs) error reporting is important, but non trivial. We discussed how this is done in Converge. We finally looked at how to integrate Converge's expression language into your DSL and how to package DSL definition for later use. The last segment look at the process of implementing a DSL in converge and about some of the history and practical experience with Converge. Lessons learned from building Converge wrap up the episode.

In this episode we discuss sensor networks with our guest Steffen Schaefer, who is the Technical Thought Leader for Sensors & Actuator Solutions at IBM. The discussion resolves around the TREC device, which can be mounted on containers to track them on their journey over seas, railway tracks and roads. The TREC is a small embedded device developed by Steffen's employer, IBM, that has various sensors and communications channels. In the episode we first talked about container transport in general, and then looked at how the TREC device works - specifically, it's hardware, software and power management. We then looked at the necessary backend infrastructure. The main part of the discussion covered the communication between the device and the backend, using technologies such as Zigby, GSM and satellite communications. We also looked at the middleware infrastructures used, such as the MQtt messaging tool. We closed the episode with a little discussion of the "Internet of Things" and some discussion about embedded software devleopment in general. Note that SE Radio will feature more embedded topics in the future - an introduction to embedded development will be put online soon.

In the first episode on Refactoring we talked about the basic ideas behind refactoring and some base principles why refactoring is a key part of software engineering. Now we move on to more complicated refactorings and discuss three major situations, their problems and possible solutions: advanced refactorings in large projects that can hardly be finished in a few minutes or hours and refactoring in larger teams. Also covered are the refactoring of published APIs and how merciless refactoring could be aligned with backward compatibility of published APIs, and refactorings that affect more than just code like for example database schemas.