Blog

Baking in Evidence

May 12, 2026

Evidence tends to be in whatever shape the tool that produced it happened to emit; a JSON blob here, a PDF there, a spreadsheet far more often than it should. So how do we ensure it is more than just output, that it consistently proves what happened? Read on...

Attestations and Evidence

May 2, 2026

Attestations and evidence are often referred to in GRC circles. They are related but not interchangeable. This post looks at definitions, interpretations and how, along with evaluations, they build trust in governance.

Controls Engineering Meetup

Apr 4, 2026

Reflections from a recent London roundtable with financial institutions on treating SDLC governance as an engineered, evidence-based system.

Man vs Model

Mar 8, 2026

A four-week, AI-assisted delivery burst measured against my own historical peaks. What shipped, how I measured it, what the numbers really say, and the guardrails that made it safe.

A Spooky Story

Feb 20, 2026

One that terrifies us all... having to grep that impenetrable log file by hand. Is using a custom Log4j appender the way to avoid this nightmare? Is routing log events to a HTTP server a good idea or a hidden maintenance trap? Let's have a look at it.

DORA Metrics Meet Governance in Banking

Jan 26, 2026

Mike Long, Nathan Harvey and I discuss how DORA metrics can be aligned with governance frameworks in the banking industry. We posted the resulting article under the Team Topologies Expert View series.

Bank on Tech Panel Discussion

Nov 12, 2025

Deutsche Bank's Bank on Tech event in London, Birmingham, and Dublin brought together technical experts and thought leaders to reflect and learn.

Don't name classes 'Impl'

Jan 1, 2023

Naming implementation classes 'Impl' obscures intent. Learn why descriptive implementation names matter and how to choose names that reflect behaviour.

Luhn Algorithm

Dec 7, 2022

Compare an imperative and functional implementation of the Luhn Algorithm. See how functional programming emphasises transformations and immutability over state mutation.

Lead Time vs Cycle Time

Jun 7, 2022

Lead time and cycle time are often confused. Understand the subtle difference, their roots in lean manufacturing, and why DORA uses Lead Time for Changes as a key metric.

Pull Requests and Trust

Jan 4, 2021

Exploring the history and implications of pull requests in software development. This post examines how PRs introduce delays, impact continuous integration, and discusses the relationship between trust and code review practices in agile teams.

Establishing an Engineering Culture

Feb 1, 2020

How trust, voice, and autonomy shape engineering culture, with practical levers drawn from Westrum, DORA, and Deming.

Evidencing Source Code Reviews

Oct 30, 2019

How to evidence source code reviews in regulated environments. Signed commits and pair programming as a code review mechanism without wasteful bureaucracy.

Creating Debian Repositories

Sep 3, 2019

Step-by-step guide to building and publishing your own Debian/Ubuntu APT repository with aptly, including package publishing, signing with GPG, and client setup.

Easily Deploy Java to Debian

Sep 2, 2019

Package Java, Scala, or Kotlin apps as .deb files and deploy via apt. Level up your distribution strategy with proper Debian package management.

Upgrade Raspbian

Aug 29, 2019

Step-by-step guide to upgrading Raspbian from Stretch to Buster on your Raspberry Pi.

Refactoring in 10 Minutes

Aug 9, 2019

An introduction to refactoring in 10 minutes. Java examples from Martin Fowler's book, plus a free xpdojo.org collection of XP training materials.

Upgrade Raspbian

Oct 26, 2017

Step-by-step guide to upgrading Raspbian from Jessie to Stretch on your Raspberry Pi.

Standard Raspberry Pi Setup

Mar 1, 2017

A standard setup guide for Raspberry Pi including OS installation, SSH configuration, and basic system setup for headless operation.

Type Classes in Scala

Aug 13, 2016

Type classes in Scala provide ad-hoc polymorphism without inheritance. Learn the pattern using implicits and understand when type classes beat traditional OOP.

Home Brew Temperature Logger

Mar 23, 2016

Build a home brew temperature logger for around $10 using a Raspberry Pi Zero and DS18B20 temperature sensor. Great starter IoT project with Scala server.

Disable Edimax Wifi Dongles LED

Jan 6, 2016

Disable the LED on the Edimax EW-7811UN Wi-Fi dongle on Raspberry Pi by recompiling the kernel module. Includes a pre-built binary if you'd rather not compile.

Pi Console Lead

Dec 28, 2015

Set up a headless Raspberry Pi Zero using an Adafruit console lead. Step-by-step guide for Mac users on El Capitan/Sierra using the Prolific PL2303 driver.

Pair Testing Doesn't Work

Sep 25, 2015

Pair tests are a poor proxy for real work. After years of giving and receiving them, the author argues for fairer, more realistic interview techniques.

Easily Switch JDK on Mac

Sep 10, 2015

Easily switch between Java versions on Mac using the java_home utility. Includes bash function to set JAVA_HOME for any installed JDK version.

Implicit Functions in Scala

Jul 14, 2015

Scala implicit functions convert types automatically when the compiler needs it. Learn how implicit conversion functions work and how to use them safely.

Implicit Parameters in Scala

Jul 3, 2015

Scala implicit parameters allow the compiler to automatically supply values marked implicit. Introduction to the three categories of Scala implicits.

JMock to Scalamock Cheat Sheet

May 9, 2015

Quick reference cheat sheet mapping JMock idioms to their Scalamock equivalents. Useful when migrating Java tests to Scala or learning Scalamock.

Scala Learning Curve

Nov 25, 2014

What does the Scala learning curve look like? Expect quick initial progress followed by a slower ramp into advanced functional features like type classes and implicits.

Scala Mixins: The Right Way

Sep 22, 2014

Scala traits can be used for both polymorphism and mixins, but mixing these uses leads to trouble. Learn when using a trait as a mixin is genuinely appropriate.

Dealing with Exceptions as Monads

Sep 21, 2014

Treat exceptions functionally using monadic types like Either, Option, and Try. Captures error handling in the type system and provides system-wide consistency.

Udemy Java 8 Course

May 20, 2014

My 'What's new in Java 8' course is live on Udemy. Covers lambdas, streams, functional interfaces and more — get 10% off with coupon code BLOG10.

Classes vs. Functions

Apr 8, 2014

Java 8 lambdas are not just syntactic sugar over anonymous classes. Explores the underlying bytecode differences and why lambdas and anonymous classes behave differently.

Functional Interfaces in Java 8

Apr 7, 2014

Functional interfaces in Java 8 are single-method interfaces. Anywhere you use a lambda, you're using a functional interface. Learn the syntax and built-in examples.

Method References in Java 8

Feb 18, 2014

Java 8 method references explained clearly. Four types with real examples: static, bound instance, unbound instance, and constructor references.

IntelliJ IDEA Retina Support JDK 1.7+

Jan 20, 2014

IntelliJ IDEA 13 retina support is broken on JDK 7 and JDK 8. Keep running on JDK 1.6 for crisp retina rendering on Macbooks.

Yet Another TeamCity Build Monitor

Jan 1, 2014

Radiate is a TeamCity build monitor that aggregates all build statuses into a single pass/fail — no cherry-picking which failures to ignore.

Currying Functions in Java & Scala

Jul 21, 2013

Currying transforms a multi-argument function into a chain of single-argument functions. Practical examples in both Java and Scala.

Automatically rebase on git pull

Jul 9, 2013

Configure Git to automatically rebase instead of merge on every pull. Covers global and per-repository configuration, including IntelliJ IDEA settings.

Calculate the Optimum Number of Threads

Jun 1, 2013

Calculate the optimal number of threads for a Java application. Covers CPU-bound vs IO-bound workloads and the formula for sizing thread pools correctly.

Writing my Book

May 24, 2013

Behind the scenes of writing 'Effective Acceptance Testing' — choosing Leanpub for self-publishing, the writing process, and why I decided to write the book.

Mac Tips

May 24, 2013

Handy Mac OS X tips for developers: keyboard shortcuts, Finder tricks, and workflow improvements to speed up your daily development tasks.

Useful Git Commands

Jan 23, 2013

A collection of useful Git commands including how to delete remote branches, switch between SSH and HTTPS, and other handy tips for everyday Git use.

Java Stack vs Deque

Jan 10, 2013

Java's Stack class is a legacy class with known problems. Use Deque (specifically ArrayDeque) instead for a proper last-in-first-out stack implementation.

Sending Messages vs Method Invocation

Oct 6, 2012

Alan Kay's original vision of OOP was about message passing, not method calls. Explores the conceptual difference and why it matters for good object-oriented design.

Daily Standups Don't Work

Sep 15, 2012

Daily standups often fail because they become status reports. Learn why standups don't work and what to do instead to improve team communication and flow.

Diff Excel with Java and Hamcrest

Sep 14, 2012

Compare Excel spreadsheets in Java tests using Hamcrest matchers and Apache POI. The simple-excel library makes asserting on spreadsheet content straightforward.

Play it Next App

Aug 28, 2012

How to use the 'Play Next' feature in iTunes and the iOS music app to queue songs without disrupting your current playlist.

FreeAgent, OAuth & HTTP (Part III)

Aug 13, 2012

OAuth and HTTP part III: making signed OAuth requests to the FreeAgent API using Java and Scribe. Practical end-to-end OAuth integration example.

FreeAgent, OAuth & HTTP (Part II)

Aug 12, 2012

OAuth and HTTP part II: calling the FreeAgent API with OAuth. Step-by-step guide to obtaining and using OAuth tokens with the Scribe library in Java.

FreeAgent, OAuth & HTTP (Part I)

Aug 11, 2012

OAuth and HTTP part I: understanding the OAuth authorisation flow. Covers the three-legged OAuth dance, tokens, and how to implement it in Java with Scribe.

Mountain Lion Carnage

Jul 28, 2012

The aftermath of upgrading to Mac OS X Mountain Lion. What broke, what needed fixing, and tips for developers upgrading their Mac.

Getting Things Done, Part II

Jul 22, 2012

Part two of Getting Things Done: dig into the GTD workflow — collecting, processing, organising, reviewing, and doing. Practical tips for making GTD work day to day.

Getting Things Done, Part I

Jul 20, 2012

An introduction to Getting Things Done (GTD) — David Allen's system for stress-free productivity. How it compares with agile practices and how to get started.

Pair Tests: What Candidates Can Expect

Jul 4, 2012

What candidates can expect from a pair programming interview test. Tips on how to prepare, what interviewers are looking for, and how to handle the pairing exercise.

HTTP Encoding Schemes

Jun 11, 2012

Understand the difference between URL encoding and form encoding (x-www-form-urlencoded) and how to correctly encode HTTP request parameters in Java.

HTTP Should be Simple

Jun 10, 2012

A simple introduction to HTTP and REST. Covers HTTP verbs, status codes, and practical Java examples using the simple-http library.

Stop Ignoring @Rules

May 5, 2012

Stop overlooking JUnit's @Rule annotation. Discover how ExternalResource, TemporaryFolder and custom rules make test setup and teardown cleaner.

Scala as a Functional OO Hybrid

Apr 3, 2012

Scala as a functional/OO hybrid: what does 'functional' really mean? Explores pure functions, side effects, and referential transparency in Scala.

Scala Exception Handling

Mar 30, 2012

Exception handling in Scala: from familiar try/catch with pattern matching to functional approaches using Either and Option types.

Exception Handling as a System Wide Concern

Mar 28, 2012

Treat exception handling as a system-wide concern. Identify boundaries in your application and handle exceptions consistently at those boundaries.

Building Better Exceptions

Mar 28, 2012

Design better exceptions by treating them as proper objects with behaviour. Apply the Law of Demeter and 'tell don't ask' to keep exception handling clean.

Expecting Exceptions JUnit Rule

Mar 27, 2012

Replace the try-fail-catch anti-pattern with JUnit's ExpectedException rule for cleaner, more readable exception testing.

Tools for bad.robots

Mar 18, 2012

Introducing robotooling: a collection of open-source Java utilities capturing reusable patterns around HTTP, Excel, Concordion, and concurrent testing.

Force IE8 to Display JSON with Jersey

Feb 21, 2012

Fix IE8 prompting to download JSON responses from Jersey REST services by setting the correct Content-Type and response headers.

Hexagonal Acceptance Testing

Feb 13, 2012

Apply hexagonal (ports and adapters) architecture to structure acceptance tests. Test at the application boundary without spinning up the full stack.

Transaction Management without the Frameworks

Jan 29, 2012

Avoid declarative transaction management frameworks like Spring. Roll your own imperative transaction management for more control and testability.

Java source on Mac

Oct 29, 2011

How to get Java source code on your Mac for IDE source attachment. Covers Maven and environment configuration.

Catching Multiple Exceptions (and rethrowing them all!)

Aug 29, 2011

How to catch multiple exceptions, process them independently, then rethrow them all. A pattern for collecting and re-throwing exceptions in batch processing.

Reflecting on Interviewing Mistakes

Aug 29, 2011

Reflecting on the last few years of heavily interviewing for agile developers. We've got the process down but often fool ourselves and let good guys slip through. Right or wrong answers don't really have a place because there's never a right or wrong answer in what we do.