Using Footnotes
How I use, and render, footnotes
2024 Analysis of Traffic to martinfowler.com
Uncovering the Seams in Mainframes for Incremental Modernisation
Mainframe systems continue to run much of the world's computing workload, but it's often difficult to add new features to support growing business needs. Furthermore the architectural challenges that make them slow to enhance also make them hard to replace. To reduce the risk involved, we should use an incremental approach to legacy displacement, gradually replacing legacy capabilities with implem
Measuring Developer Productivity via Humans
Measuring developer productivity is a difficult challenge. Conventional metrics focused on development cycle time and throughput are limited, and there aren't obvious answers for where else to turn. Qualitative metrics offer a powerful way to measure and understand developer productivity using data derived from developers themselves. Organizations should prioritize measuring developer productivity
What if we rotate pairs every day?
Benefits of pair programming are widely accepted but advice around pair rotation remains controversial. When and how frequently should teammates rotate pairs? And… What if we rotate pairs every day? We worked with three teams through an exercise of daily pair rotation. We developed a lightweight methodology to help teams reflect on the benefits and challenges of pairing and how to solve them. Init
Patterns of Legacy Displacement
When faced with the need to replace existing software systems, organizations often fall into a cycle of half-completed technology replacements. Our experiences have taught us a series of patterns that allow us to break this cycle, relying on: a deliberate recognition of the desired outcomes of displacing the legacy software, breaking this displacement in parts, incrementally delivering these parts
Periodic Face-to-Face
Engineering Practices for LLM Application Development
LLM engineering involves much more than just prompt design or prompt engineering. In this article, we share a set of engineering practices that helped us deliver a prototype LLM application rapidly and reliably in a recent project. We'll share techniques for automated testing and adversarial testing of LLM applications, refactoring, as well as considerations for architecting LLM applications and r
Continuous Integration
Continuous Integration is a software development practice where each member of a team merges their changes into a codebase together with their colleagues changes at least daily. Each of these integrations is verified by an automated build (including test) to detect integration errors as quickly as possible. Teams find that this approach reduces the risk of delivery delays, reduces the effort of in
Legacy Seam
Software And Engineering
Test Driven Development
Diff Debugging
Catalog of Patterns of Distributed Systems
Distributed systems provide a particular challenge to program. They often require us to have multiple copies of data, which need to keep synchronized. Yet we cannot rely on processing nodes working reliably, and network delays can easily lead to inconsistencies. Despite this, many organizations rely on a range of core distributed software handling data storage, messaging, system management, and co
Three reasons a liberal arts degree helped me succeed in tech
A traditional liberal-arts degree provides skills that are highly relevant for a product manager
Headless Component: a pattern for composing React UIs
As React UI controls become more sophisticated, complex logic can get intertwined with the visual representation. This makes it hard to reason about the behavior of the component, hard to test it, and necessary to build similar components that need a different look. A Headless Component extracts all non-visual logic and state management, separating the brain of a component from its looks.
Creating an integrated business and technology strategy
To make fruitful use of technology, we need to align our technology thinking with underlying business plans. A technology strategy can drive this alignment, providing it properly integrates business and technology. We have developed a conceptual framework to help us with this strategic thinking, based on recognizing common aspects of strategic initiatives, leading us to identify eleven prevalent s
Demo Front-End
Have you ever attended a “demo” where developers were proudly showing screen after screen of JSON output from their API, while users were confused and distracted, unable to make any sense of it? Have you ever tried to use an API in development, and been frustrated by how difficult it is to find the correct JSON payload and header incantations to be able to test a feature? A Demo Front-End is a sim
Team Topologies
Two Pizza Team
How platform teams get stuff done
Platform teams have a unique reliance on other teams to ensure adoption of their platform - getting code changes into other teams' codebase is critical to their success. There are a variety of patterns for that cross-team collaboration, and selecting the right ones depends on both the phase of platform adoption and the ability of both teams and codebases to accept external influence.
Decentralizing the Practice of Architecture at Xapo Bank
Xapo was founded as a Bitcoin service provider and developed into an online bank. During this transition it needed to reassess its software estate and establish an architecture capability to guide its future. It took on ideas from Domain-Driven Design, Team Topologies, and the Architecture Advice Process to develop an Architectural Advice Forum. This led to greater alignment of its software delive
Building Boba AI
We are building an experimental AI co-pilot for product strategy and generative ideation called “Boba”. Along the way, we’ve learned some useful lessons on how to build these kinds of applications, which we’ve formulated in terms of patterns. These patterns allow an application to help the user interact more effectively with a Large-Language Model (LLM), orchestrating prompts to gain better result
Linking Modular Architecture to Development Teams
Can a modular architecture improve software delivery? Yes! -but with some caveats. This article charts the journey of an enterprise who set out to shift their architecture to a more modular one in order to ease their growing pains. They found that modularity is a multifaceted solution that extends beyond architecture, into business lines of communication, team topologies and effective developer ex
Dependency Composition
Based on frustrations with conventional framework-based dependency injection, I have adopted a composition strategy that utilizes partial application to inject context into modules. When combined with test-driven development as the design process and a focus on functions over classes, modules can be kept clear, clean, and mostly free of unintended coupling.
Using ChatGPT as a technical writing assistant
An experienced technical author explores using ChatGPT to assist with a number of writing projects. He finds ChatGPT can provide time-savings through drafts and prompting for additional content, but lacks accuracy and depth - as well as suffering from bubbly optimism. Overall it is useful if you work iteratively, asking for small chunks with well-crafted prompts.
What Does a Technical Author Look Like?
Asking Stable Diffusion for "portrait of technical author"
An example of LLM prompting for programming
My account of an internal chat with Xu Hao, where he shows how he drives ChatGPT to produce useful self-tested code. His initial prompt primes the LLM with an implementation strategy (chain of thought prompting). His prompt also asks for an implementation plan rather than code (general knowledge prompting). Once he has the plan he uses it to refine the implementation and generate useful sections o
Timeboxed Iterations
Continuous Flow
Slack
Modularizing React Applications with Established UI Patterns
Established UI patterns are often underutilized in the frontend development world, despite their proven effectiveness in solving complex problems in UI design. This article explores the application of established UI building patterns to the React world, with a refactoring journey code example to showcase the benefits. The emphasis is placed on how layering architecture can help organize the React
Retrospectives Antipatterns
If you use retrospectives, or any kind of meeting where people are supposed to discuss and learn from their discussions, you will have experienced less efficient sessions from time to time. There is no wonder in that, and it happens to most people. This article describes and offers solutions for three of these unfortunate situations: skipping generating insights, getting lost in things you can't c
Data Mesh Accelerate Workshop
To accelerate means to move faster, to gain speed. Effectively working with data is key for any organization that wants to thrive in the modern world, and Data Mesh is showing organizations how to realise value from their data, at scale. The Data Mesh Accelerate workshop helps teams and organisations accelerate their Data Mesh transformation, by understanding their current state and exploring what
Your organization should run its own Mastodon server
Run your own Mastodon server to control your social media presence
Exploring Mastodon
With the current uncertainty over Twitter, I'm starting to explore using Mastodon
Conway's Law
How I use Twitter
The things I do to make Twitter useful and avoid the time-traps
Lean Inception
An inception is an activity done at the start of a project to gather together the people involved and set a common direction and working style for the on-going work. The lean inception is a focused form of inception, which can be done in a single week. During this time we understand the key features and customers for the product, and build a canvas to formulate the characteristics of a Minimum Via
Building Infrastructure Platforms
Infrastructure Platform teams enable organisations to scale delivery by solving common product and non-functional requirements with resilient solutions. This allows other teams to focus on building their own things and releasing value for their users. But nobody said building scalable platforms was easy... In this article Poppy and Chris explore 7 key principles which can help you build the right
Scaling the Practice of Architecture, Conversationally
Architecture need not be a monologue; delivered top-down from the minds and mouths of a centralised few. This article describes another way to do architecture; as a series of conversations, driven by a decentralised and empowering decision-making technique, and supported by four learning and alignment mechanisms: Decision Records, Advisory Forum, Team-sourced Principles, and a Technology Radar
You Can't Buy Integration
Commercial integration tools are a couple decades old now, but there has been little in the way of overarching architectural principles describing when and how to use them. In this article, I argue that “buy” decision mechanics have caused us to exaggerate the value proposition of such tools, often leading to mandates to use a certain integration tool over a general purpose language. I claim that
Default Trial Retire
The strong and weak forces of architecture
Good technical design decisions are very dependent on context. Teams that regularly work together on common goals are able to communicate regularly and negotiate changes quickly. These teams exhibit a strong force of alignment, and can make technology and design decisions that harness that strong force. As we zoom out in a larger organisation an increasingly weak force exists between teams and div
Compliance in a DevOps Culture
Integrating the necessary Security Controls and Audit capabilities to satisfy Compliance requirements within a DevOps culture can capitalize on CI/CD pipeline automation, but presents unique challenges as an organization scales. Understanding the second order implications and unintended consequences caused by the chosen implementation is key to building an effective, secure, and scalable solution.
Ship / Show / Ask
Ship/Show/Ask is a branching strategy that combines the features of Pull Requests with the ability to keep shipping changes. Changes are categorized as either Ship (merge into mainline without review), Show (open a pull request for review, but merge into mainline immediately), or Ask (open a pull request for discussion before merging).
On the Diverse And Fantastical Shapes of Testing
There are arguments about whether a testing portfolio should be a pyramid or more like honeycomb. My second biggest issue with this argument is that it's rendered opaque by the fact that it's not clear what people see as the difference between unit and integration tests.
Mind the platform execution gap
Developer productivity platforms are increasingly recognised as a way to manage the cognitive load of engineering teams and decrease time to market for new features. However, there are baseline capabilities that organisations need to cultivate in order to successfully execute on a plaform strategy. The platform team needs to think of the platform as a software product, needing dialog with its user
Muted spaghetti line charts with R's ggplot2
How I plot a muted-spaghetti chart with R, including facets.
Bitemporal History
It's often necessary to access the historical values of some property. But sometimes this history itself needs to be modified in response to retroactive updates. Bitemporal history treats time as two dimensions: actual history records what history should be given perfect transmission of information, while record history captures how our knowledge of history changes.
Refinement Code Review
Pull Request
Maximizing Developer Effectiveness
Technology is constantly becoming smarter and more powerful. I often observe that as these technologies are introduced an organization’s productivity instead of improving has reduced. This is because the technology has increased complexities and cognitive overhead to the developer, reducing their effectiveness. In this article, the first of a series, I introduce a framework for maximizing develope
The Lies that can Undermine Democracy
Recent events highlight our need to take serious measures to counter lies that are undermining democracies.
Data Mesh Principles and Logical Architecture
Our aspiration to augment and improve every aspect of business and life with data, demands a paradigm shift in how we manage data at scale. While the technology advances of the past decade have addressed the scale of volume of data and data processing compute, they have failed to address scale in other dimensions: changes in the data landscape, proliferation of sources of data, diversity of data u
Don't put data science notebooks into production
We've come across many clients who are interested in taking the computational notebooks developed by their data scientists, and putting them directly into the codebase of production applications. Data science ideas do need to move out of notebooks and into production, but trying to deploy that notebooks as a code artifact breaks a multitude of good software practices. Predictably, that results in
Computational Notebook
Should social media dampen uncertain stories?
When a news story of dubious provenance appears, should social media use a temporary block to slow its spread?
Thoughts writing a Google App script
A google sheets script is a handy way to share a short script for non-programmers.
Don't Compare Averages
In business meetings, it's common to compare groups of numbers by comparing their averages. But doing so often hides important information in the distribution of the numbers in those groups. There are a number of data visualizations that shine a light on this information. These include strip charts, histograms, density plots, box plots, and violin plots. These are easy to produce with freely avail