As we grow our application portfolio, we soon discover common bits of code used by two or more applications. Often our first reaction is to break these common bits out into shared libraries. If you’re still using an application server, you might even put these libraries in the server itself so other applications can pick them up. After all, why repeat yourself? Certainly there are situations where that makes a lot of sense. Improved application startup time is one benefit. But not always. Sometimes these shared libraries actually hinder your team’s ability to deliver working software. Here I’ll explain why there is such thing as too much sharing.
As a software development team grows and adds more members, what worked with one or two people no longer works as effectively. The team realizes they need to set up some sort of standard process for developing software. It need not be complicated, just a lightweight process will do. All they need is a way to get organized with a simple development approach. Here is what has worked well for my teams. Adapt it according to your team’s circumstances.
Application deployments have usually meant deploying a new version of an artifact to Production, with stops along the way in Test, Staging, etc. All the new features and bug fixes become active when you deploy this new version. Although you’ve thoroughly tested the application with automated unit tests, functional tests, load tests, and performance tests, you’ve only reduced the risk of something going wrong in Production. If and when something does go wrong, you may need to rollback to the previous version. But what if the fix wasn’t as dramatic as a rollback? What if you could revert the one mis-behaving feature? Even better, what if you could select which features to activate? In this article I’ll explain how you can control your deployments with feature flags.
History of Representational State Transfer
Roy Fielding coined the term Representational State Transfer (REST) in his 2000 doctoral thesis Architectural Styles and the Design of Network-based Software Architectures. In essence, he argues an API should use the existing HTTP verbs, and it should focus on representations of business objects rather than backend implementations. An example might be to model a Customer object the way the business knows and interacts with it rather than how it’s stored on the customer database table. In this post I’ll describe how to design an effective REST API using some of the concepts Fielding pioneered.
Most software development teams have one person with the role of Architect. Small teams of one or two people may not, but someone is thinking about architecture. This person’s title may be Solution Architect, Application Architect, Data Architect or Systems Architect. For now let’s consider all of them under the collective name of Software Architect. In this article I’ll talk about the characteristics of a good architect, and I’ll explain what a software architect does. I’ll also address the evolution of the role of software architect, and where it is today. By the end I hope you’ll have an answer to the question “so what does a software architect do anyway?”
What is it?
The pipeline architecture is one of the most common architecture styles used in designing software systems. Also known as pipes and filters, it consists of a series of discrete steps performed in a predictable sequence. This is different from the model-view-controller pattern in a layered architecture. In this article I’ll define what it is and when to use the pipeline architecture style.
So it’s time to move one of your legacy web applications from your on-premise data centre to a public cloud provider such as Amazon Web Services (AWS), Microsoft Azure, or Google Cloud Platform (GCP). This may be a decision you made, or one that your leadership team made. In this post I’ll explain what you need to think about when figuring out how to migrate your web application to the cloud.
Microservices are all the rage these days. You’ve seen so many blog posts, technical articles, even job postings calling for microservices experience. So it must be the new way to architect applications, right?
Well, as with everything else in software architecture, it depends. It depends on the context you are dealing with. It depends whether the benefits of microservices outweigh their drawbacks for your situation.
In this post I’ll describe what microservices are, why they’re so good, and what their drawbacks are. I’ll finish off by giving you some guidelines to help you decide whether microservices are right for your situation.
A layered architecture style is one where the presentation, business and persistence layers are bundled into one deployment unit. In this article I’ll discuss what it is, and point out the situations where you would choose to adopt it.
This is one of a series of articles where I am going to discuss each of these architecture styles: Layered, Microservices, Pipeline, Microkernel, Service-Based, Event-Driven, Space-Based, and Orchestration-Driven Service-Oriented Architecture (SOA). I’ll provide some insights based on my experiences, and I’ll mention some of the Java / JVM frameworks that support the style we’re talking about.
Adopting the hexagonal architecture pattern produces software that is more maintainable. It enables you to respond to changes with less fuss than many other architectural patterns. In this article I’ll explain why and offer my thoughts on this pattern.
What is a Hexagonal Architecture?
Alistair Cockburn first coined the term Hexagonal Architecture on his blog in 2005. Also known as the Ports and Adapters pattern, it is a layered architecture. It is a way of separating the domain concerns while making unit tests easier to write and changes simpler to accommodate.