Here is a list of recent updates the site. You can also get this information as an RSS feed and I announce new articles on Fediverse (Mastodon), Bluesky, LinkedIn, and X (Twitter) .
I use this page to list both new articles and additions to existing articles. Since I often publish articles in installments, many entries on this page will be new installments to recently published articles, such announcements are indented and don't show up in the recent changes sections of my home page.
Tue 18 Feb 2025 07:02 +07
Recent LLM models have provided “reasoning” capabilities. Birgitta Böckeler asks what role these play with coding tasks. She doesn't have an answer, but does have questions and thoughts - and has not found such capabilities worthwhile so far.
Thu 13 Feb 2025 21:16
LLMs struggle with large amounts of context. Bharani Subramaniam and I explain how to mitigate this common RAG problem with a Reranker which takes the document fragments from the retriever, and ranks them according to their usefulness.
Wed 12 Feb 2025 07:58
Users often have difficulty writing the most effective queries. Bharani Subramaniam and I explain Query Rewriting: getting an LLM to formulate alternative queries to send to a RAG's retriever.
Thu 06 Feb 2025 09:17
The appearance of DeepSeek Large-Language Models has caused a lot of discussion and angst since their latest versions appeared at the beginning of 2025. But much of the value of DeepSeek's work comes from the papers they have published over the last year. Shayan Mohanty provides an overview of these papers, highlighting three main arcs in this research: a focus on improving cost and memory efficiency, the use of HPC Co-Design to train large models on limited hardware, and the development of emergent reasoning from large-scale reinforcement learning
Wed 05 Feb 2025 10:03
Today Bharani Subramaniam and I outline four limitations to the simple RAG from yesterday, and the pattern that addresses the first of these: Hybrid Retriever. This tackles the inefficiencies of embeddings-based search by combining it with other search techniques.
Tue 04 Feb 2025 10:23
was on a panel at goto Copenhagen last September with Holly Cummings, Trisha Gee, Dave Farley, and Daniel Terhorst-North. We discussed the current state of software development and where it was heading. Given the timing, there was much discussion about the role AI would play in our profession's future.
Tue 04 Feb 2025 09:57
A pre-trained GenAI model lacks recent and specific information about a domain. Bharani Subramaniam and I explain how Retrieval Augmented Generation (RAG) can fill that gap.
Thu 30 Jan 2025 00:00 +07
The Forest and the Desert is a metaphor for thinking about software development processes, developed by Beth Andres-Beck and hir father Kent Beck. It posits that two communities of software developers have great difficulty communicating to each other because they live in very different contexts, so advice that applies to one sounds like nonsense to the other.
The desert is the common world of software development, where bugs are plentiful, skill isn't cultivated, and communications with users is difficult. The forest is the world of a well-run team that uses something like Extreme Programming, where developers swiftly put changes into production, protected by their tests, code is invested in to keep it healthy, and there is regular contact with The Customer.
Clearly Beth and Kent prefer The Forest (as do I). But the metaphor is more about how description of The Forest and the advice for how to work there often sounds nonsensical to those whose only experience is The Desert. It reminds us that any lessons we draw about software development practice, or architectural patterns, are governed by the context that we experienced them. It is possible to change Desert into Forest, but it's difficult - often requiring people to do things that are both hard and counter-intuitive. (It seems sadly easier for The Forest to submit to desertification.)
In this framing I'm definitely a Forest Dweller, and seek with Thoughtworks to cultivate a healthy forest for us and our clients. I work to explain The Forest to Desert Dwellers, and help my fellow Forest Dwellers to make their forest even more plentiful.
The best short summary from Beth and Kent is on Kent's Substack. For more depth, take a look at their keynote at Øredev.
Kent Beck supplied the image, which he may have painstakingly drew pixel by pixel. Or not.
Wed 29 Jan 2025 10:55
GenAI systems, like many modern AI approaches, have to handle vast quantities of data, and find similarities between elements in an image or chunk of words. Bharani Subramaniam and I describe a key tool to do this - Embeddings - transforming large data blocks into numeric vectors so that embeddings near each other represent related concepts
Tue 28 Jan 2025 07:43
Everyone is fascinated about using generative AI these days, and my colleagues are no exception. Some of them have had the opportunity to put these system into practice, both as proof-of-concept, and more importantly as production system. I've known Bharani Subramaniam for many years as a technology leader in India, he's been assembling the lessons we've learned and I've worked with him to describe them as patterns.
In this first installment, we look the limits of the base case of Direct Prompting, and how we might assess the capability of a system using Evals.
Fri 24 Jan 2025 13:01
Luca Rossi hosts a podcast (and newsletter) called Refactoring, so it's obvious that we have some interests in common. The tile comes from me leaning heavily on Beth Anders-Beck and Kent Beck's metaphor of The Forest and The Desert. We talk about the impact of AI on software development, the metaphor of technical debt, and the current state of agile software development.
Wed 22 Jan 2025 10:54
Juntao Qiu finishes his description of codemods by looking at some other approaches outside the JavaScript world such as JavaParser and OpenRewrite.
Wed 15 Jan 2025 11:43
So far the codemods that Juntao Qiu has described are fascinating, but rather straightforward. Real codebases offer more challenges. In this installment, he goes into how to tackle more complicated cases by composing codemods.
Thu 09 Jan 2025 09:49
I've got into the habit of starting the New Year by sharing six favorite albums I discovered during the last year. This years set includes Celtic jazz, trip-hop neo-fado, jazz-fusion for the 2020's, playful harmonies, and a vibrant collaboration between Indian classical musicians and a string quartet. (I was also unable to limit myself to six.)
Wed 08 Jan 2025 09:44
Juntao Qiu moves onto a more complex example of a codemod, one that extracts a tooltip responsibility from a JSX component. This illustrates how to manipulate the AST in several steps.
Tue 07 Jan 2025 09:34
As a library developer, you may create a popular utility that hundreds of thousands of developers rely on daily, such as lodash or React. Over time, usage patterns might emerge that go beyond your initial design. When this happens, you may need to extend an API by adding parameters or modifying function signatures to fix edge cases. The challenge lies in rolling out these breaking changes without disrupting your users’ workflows. Juntao Qiu begins an article to explain how we can use codemods to tackle this. Codemods are a tool automating large-scale code transformations, allowing developers to introduce breaking API changes, and refactor legacy codebases.
Thu 12 Dec 2024 10:36
Design tokens are fundamental design decisions represented as data. Andreas Kutschmann explains how they work and how to organize them to balance scalability, maintainability and developer experience.
Tue 10 Dec 2024 15:22
Once we've designed our initial data products, Kiran Prakash finishes his article by leading us through the next steps: identifying common patterns, improving the developer experience, and handling governance.
Wed 04 Dec 2024 10:36
Having got an initial data product, Kiran Prakash leads us through the next steps: covering similar uses cases to generalize the data product, determining which domains the products fit into, and considering service level objectives.
Tue 03 Dec 2024 09:04
Increasingly the industry is seeing the value of creating data products as a core organizing principle for analytic data. Kiran Prakash has helped many clients design their data products, and shares what he's learned. In particular his methodical approach doesn't begin by thinking about some data that might be handy to share, but instead works from what consumers of a data product need.
Tue 19 Nov 2024 10:17
A very powerful new coding assistance feature made its way into GitHub Copilot at the end of October. This new “multi-file editing” capability expands the scope of AI assistance from small, localized suggestions to larger implementations across multiple files. Birgitta Böckeler tries out this new capability and finds out how useful its changes tend to be, and wonders about what feedback loops are needed with them.
Wed 13 Nov 2024 12:33
With the recent uptick in tech activity on Bluesky, I've decided that I will start posting there in addition to my current locations.
I've also put together my general thoughts on the state of social media, and how I'm using it, now that it's two years since The Muskover.
Tue 05 Nov 2024 08:55
Matthew Foster and John Mikel Amiel Regida finish their account of how they incrementally modernized a mobile application by looking at the results of their work. They achieved a significant shortening of time to new value, and found that changes in the new application could be prepared in about half the time it took on the old codebase.
Wed 30 Oct 2024 10:29
Matthew Foster and John Mikel Amiel Regida dive into the details of incrementally modernizing a legacy mobile application. They look at how to implant the strangler fig into the existing app, setting up bi-directional communication between the new app and the legacy, and ensuring effective regression testing on the overall system.
Tue 29 Oct 2024 10:34
My colleagues are often involved in modernizing legacy systems, and our approach is to do this in an incremental fashion. Doing this with a mobile application raises some specific challenges. Matthew Foster and John Mikel Amiel Regida share their experiences of a recent engagement to do this, shifting from a monolithic legacy application to one using a modular micro-app architecture.
Fri 04 Oct 2024 09:16
I was interviewed on the Book Overflow podcast about the Refactoring book. We talked about the origins of the book, the relationship between refactoring, testing, and extreme programming, how refactoring is used in the wild, and the role of books and long-form prose today.
Tue 24 Sep 2024 09:51
Alessio Ferri, Tom Coggrave, and Shodhan Sheth complete their article on what they have learned from using GenAI with legacy systems. They describe how GenAI's ability to process unstructured information makes it much easier to build a capability map of a legacy system, tying the capabilities of a system to the relevant parts of the source code. GenAI is also useful for identifying areas of dead code, and has promise for better translations of a system between platforms and languages.
Wed 18 Sep 2024 08:08
Alessio Ferri, Tom Coggrave, and Shodhan Sheth use their combination of an AST-fueled knowledge graph and LLMs to gain understanding of legacy systems. They have found it aids them both in extracting the low-level details of the code and can provide high-level explanations to support human-centered approaches such as event storming.
Tue 17 Sep 2024 09:07
Most of the talk about the impact of GenAI on software development is about its ability to write (messy) code. But many of us think it's going to be much more useful to help us understand existing messy code, as part of a modernization effort. My colleagues Alessio Ferri, Tom Coggrave, and Shodhan Sheth have been considering how GenAI can do this, including building an internal tool to help explore the possibilities. The tool uses an LLM to enhance a knowledge graph based on the AST of the code base. It also uses an LLM to help users query this knowledge graph.
Thu 05 Sep 2024 09:37
Decentralized data management requires automation to scale governance effectively. Fitness functions are a powerful automated governance technique my colleagues have applied to data products within the context of a Data Mesh. Since data products serve as the foundational building blocks of a data strategy, ensuring robust governance around them significantly increases the chances of success. Kiran Prakash explains how to do this, starting with simple tests for key architectural characteristics and moving on to leveraging metadata and Large Language Models.