Architecture

July 29th, 2018

Autonomous bubbles and event streams: Pragmatic approaches to working with legacy systems

It’s easy to get caught up in unrealistic notions that you can re-write a legacy system or gradually decompose it. There are other, more pragmatic approaches that can help to modernise architectures and enable new development.

July 10th, 2018

Kafka on Azure Event Hub – does it miss too many of the good bits?

Microsoft have added a Kafka façade to Azure Event Hubs, presumably in the hope of luring Kafka users onto its platform. This makes sense as the platforms have a lot in common, though there are some missing Kafka features that may prove critical.

June 18th, 2018

Using architectural “fitness functions” as a guide to system design

Fitness functions can be a useful metaphor for guiding an emerging architecture, but you do have to invest in making sure they describe the right outcome.

June 3rd, 2018

Layers, onions, hexagons and the folly of application-wide abstractions

Not only are layered applications difficult to maintain, but the common abstractions they are built on tend to give rise to inflexible implementations that have serious scalability challenges.

May 8th, 2018

How to decompose that monolith into microservices. Gently does it…

You’re rarely given the opportunity to focus on transitioning an architecture to the exclusion of everything else. You may have to get used to the idea that decomposing a monolith is a direction of travel rather than a clear destination.

March 9th, 2018

Microservice preconditions: what needs to be in place before you decompose that monolith…

One of the main benefits of microservices is that they reduce the cost of change. The problem is that you need to make a significant up-front investment to realise this saving. Your first few microservices are more likely to be an expensive and potentially painful undertaking.

February 16th, 2018

Relax. There’s no conflict between architecture and agile.

Agile teams still need to make architecture decisions, but in supporting them architects should seek “just enough” architecture over “big design up front” and practical solutions over large-scale abstract thinking.

January 27th, 2018

Can TOGAF and Agile really go together?

On the face of it, TOGAF describes a very different world to the agile preference for working software over documentation. That doesn’t mean that TOGAF is incompatible with agile, so long as you’re prepared to adapt its numerous building blocks.

December 13th, 2017

Entity services: when microservices are worse than monoliths

Finely-grained, entity-based services seem to be advocated by some pretty authoritative sources. This is unfortunate as they are something of an anti-pattern that can undermine many of the benefits of decomposing an monolith into micoservices.

December 3rd, 2017

Automating Docker image deployments using Azure Container Instances

Azure’s Container Instances provides an easy and quick way to run Docker images without having to learn the various complexities of orchestration platforms such as Kubernetes.

November 4th, 2017

Events, sagas and workflows: managing long-running processes between services

An event-driven architecture can give rise to complex chains of events that are difficult to manage. These problems can be mitigated through careful design rather than resorting to shared state databases or workflow engines.

October 12th, 2017

What should a Scaled Agile “architectural runway” actually look like?

The Scaled Agile Framework talks about an “architectural runway” as the main deliverable for agile architecture, yet it’s vague on the detail of what this looks like.

September 20th, 2017

How can Domain Driven Design help with large scale agile development?

Agile teams spend time modelling software whether they are prepared to admit it or not. Adopting a technique like Domain Driven Design can help to make this more efficient, particularly at scale.

July 5th, 2017

Writing unit tests for Azure Functions using C#

You can now write compiled Azure functions in C# with full unit test coverage, though there are a few obstacles along the way.

June 4th, 2017

Can consumer-driven contracts manage breaking change in microservice integrations?

One of the more enduring problems with service integration is managing change in service interfaces. Consumer-driven contracts can help to detect breaking changes, but this visibility comes at a price.