Architecture

The Research and Development department would appear to give equal weight to both research and development by virtue of naming, yet there are few engineers who would claim that research is a primary responsibility of their job. Between working on product features, planning sprints, fixing bugs, and attending meetings there is little time left for research. But what is the cost of foregoing research in favour of development? In this article, I consider the economic cost of ignoring research and argue that focusing solely on development is harmful to both product and engineering....

While microservices have become the defacto architectural pattern for building modern systems, they come with their own set of challenges. Key among them is ensuring application data consistency when data is spread over multiple databases. This article discusses one solution to this problem, distributed sagas. Distributed sagas provide consistency guarantees for systems spanning multiple databases in the face of failure using a clear and manageable implementation pattern. A saga is highly related to a finite state machines that moves consistently through a set of states, ensuring at each step that some conditions hold....

Complex systems exhibit unexpected behavior. — John Gall, The Systems Bible One reaction to the myriad failure cases we encounter with distributed systems is to add more testing. Unfortunately, testing is a best-effort verification of system correctness — we simply cannot predict the failure cases that will happen in production. What’s more, any environment that we use to verify system behaviour is — at best — a pale imitation of our production environment....

Early computers were described using mathematical notation and theoretical constructions, which were then translated by enterprising machinists into custom built calculation engines. The first computer programmers using these machines built applications directly in hardware by plugging together wires and sockets in varying configurations. Even with these short-comings, the value of general purpose computing machines was evident. As companies began to realize the utility of computing, they saw computing as a means for differentiating themselves from their competitors....

A principle is a concept or value that is a guide for behaviour or evaluation. — Wikipedia This post presents a principled approach to architecture. These principles specify what I believe is important about architecture, without diving into any details about how an architect should work. No matter how an architect works day-to-day, by following principles, you can be sure you are providing value in the right areas. As usual, this post is personal opinion, and I’m interested in hearing any differing or similar opinions in the comments....

One proposed benefit of following a microservice architecture is that each service can be developed, released, and supported independently. In theory this allows development teams to work with less coordination and less overhead, leading to faster development times. In practice, this is difficult to achieve without some guidelines that make it work. The book The Tao of Microservices provides two such guidelines — transport independence, and pattern matching — that create an environment allowing you to compose services....

In most organizations, software development is split between two groups — product management and engineering. Product management is focused on building the right system. This requires product managers to meet with users, try and understand their needs, and develop solutions that meet those needs. To actually develop the solution, product managers must involve engineers who are focused on building the system right — writing the code, making it stable, and supporting it in production....

We all know that a page that loads in three seconds will provide a negative user experience. But does having every page load in less than one second make a meaningful difference? How can you tell? When is enough … enough? Non-functional requirements such as performance are often not precise enough to be specified as discrete numbers. Rather, they work on a sliding scale of acceptability. Would slightly better performance be significantly more valuable from a market perspective?...

Bertrand Meyer first introduces the principle of Command Query Separation in his book Object-Oriented Software Construction. The principle states that a well designed object should have methods that are either commands or queries. A command changes the state of an object, but does not return any data, while a query returns data and does not change any state. By dividing methods into these two categories, you will have a better understanding of what does, and what does not, change the state of your system....

Architecture is the bridge between (often abstract) business goals and the final (concrete) resulting system. – Software Architecture in Practice A software architect should act as a bridge between business stakeholders and technical stakeholders. To be this bridge requires understanding the business problem being solved, and being able to distill that problem into a technical solution that a software team can implement. In essence, the architect acts as a technical business analyst that helps to define the needs of an organization and recommend solutions that deliver value to stakeholders....