Schrödinger's functions: not the pure functions your are looking for
What make a pure function pure? What make a stable system stable? Read more...
Book notes: Design It!: From Programmer to Software Architect
Book notes on "Design It!: From Programmer to Software Architect" by Michael Keeling Read more...
Are you asking too much from your team/tech lead?
Expectations for a technical or/and a team leader Read more...
Book notes: Software Architecture: The Hard Parts
Book notes on "Software Architecture: The Hard Parts" by Neal Ford, Mark Richards, Pramod Sadalage and Zhamak Dehghani Read more...
But life had other plans ...
In May 2021 I took a sabbatical to take care of family, but things did not go as planned. Read more...
Image attribution:
Image by Colin Behrens from Pixabay
CTO last day: reflections, mistakes, and some learnings
Burning my hands on the steering wheel. Read more...
Book notes: Staff Engineering: Leadership beyond the management track
Book notes on "Staff Engineering: Leadership beyond the management track" by Will Larson Read more...
Book notes: Monolith to Microservices: Evolutionary Patterns to Transform Your Monolith
Book notes on "Monolith to Microservices" by Sam Newman Read more...
The self-inflicted denial-of-service (DDoS) attack
Reviewing a pull request has bring back "fond" memories of an outage from a previous life. Read more...
Book notes: Turn the Ship Around!
Book notes on "Turn the Ship Around!" by L. David Marquet Read more...
My personal path to Senior developer ... and beyond!
Yet another "how to become a senior developer" blog post Read more...
Image attribution:
Photo by Beth Macdonald on Unsplash, but with proper Gandalf's beard and eyebrows.
Book notes: Sooner, safer, happier: Antipatterns and patterns for business agility.
Book notes on "Sooner, safer, happier" by Jonathan Smart Read more...
Book notes: Fundamentals of Software Architecture
Book notes on "Fundamentals of Software Architecture" by Mark Richards and Neal Ford Read more...
Implementing DORA key software delivery metrics
Deep dive on how to implement the four key software delivery metrics. Read more...
Book notes: Grokking Simplicity
Book notes on "Grokking Simplicity" by Eric Normand Read more...
Book notes: The Subtle Art of Not Giving a F*ck
Book notes on "The Subtle Art of Not Giving a F*ck" by Mark Manson Read more...
Book notes: Designing Data-Intensive Applications
Book notes on "Designing Data-Intensive Applications" by Martin Kleppmann Read more...
Book notes: Zen & the Art of Motorcycle Maintenance
Book notes on "Zen & the Art of Motorcycle Maintenance" by Robert M. Pirsig Read more...
Book notes: Thinking in Systems.
Book notes on "Thinking in Systems" by Donella H. Meadows Read more...
First ever resilience test
Building confidence on the resilience of a home automation system. Read more...
Image attribution:
Kurzschluss 12V20A / CC BY-SA 3.0.
CTO day 7: Lucky Lotto, chaos engineering but for teams
Building resilience teams with chaos engineering principles. Read more...
Book notes: Shape Up: Stop Running in Circles and Ship Work that Matters.
Book notes on "Shape Up" by Ryan Singer Read more...
CTO day 6: Building bridges with a "Week of little things"
Giving the steering wheel to the rest of the organization. Read more...
Book notes: Unlearn: Let Go of Past Success to Achieve Extraordinary Results
Book notes on "Unlearn" by Barry O'Reilly Read more...
CTO day 5: Building bridges with "Adopt a developer"
Getting the Developer team closer to the rest of the organization Read more...
Book notes: 97 Things Every Engineering Manager Should Know
Book notes on "97 Things Every Engineering Manager Should Know" edited by Camille Fournier Read more...
Book notes: Value Stream Mapping
Book notes on Karen Martin and Mike Osterling "Value Stream Mapping" Read more...
The feeling of Trunk-Based Development
How Trunk-Based Development really feels Read more...
Book notes: A Philosophy of Software Design
Book notes on John Ousterhout's "A Philosophy of Software Design" Read more...
CTO day 4: Team building with "I dare you" challenge
A fun(???) exercise to gel a team by challenging them to achieve the impossible within a day. Read more...
Book notes: Project to Product
Book notes on Mik Kersten "Project to Product" Read more...
Prometheus in a Clojure stack: Duct, Jetty, Compojure/Reitit and Hugsql
How to integrate a Clojure HTTP service with Prometheus Read more...
Book notes: Team Topologies
Book notes on Matthew Skelton and Manuel Pais "Team Topologies" Read more...
Continuous improvement with Toyota Kata
The Toyota Kata in Software Development Read more...
Book notes: Level Up Agile with Toyota Kata
Book notes on Jesper Boeg's "Level Up Agile with Toyota Kata" Read more...
CTO day 3: Meeting "The Business"
Getting to know the business in a shit-uation, and making work visible (at its best!). Read more...
CTO day 2: downsizing the team
On your first day as newly appointed CTO you are working on your hiring strategy, the second day your organization asks you to downsize the team. Read more...
Course notes: Time Management for Technical Leaders
Course notes on Patrick Kua's "Time Management for Technical Leaders" Read more...
CTO day 1: first steps and hiring framework
First steps on my journey as CTO Read more...
Where TDD falls short, find yourself a good REPL
TDD is an awesome workflow, but not for everything. Read more...
Book notes: Good Strategy, Bad Strategy
Book notes on Richard Rumelt's "Good Strategy / Bad Strategy" Read more...
Book notes: Elements of Clojure
Book notes on "Elements of Clojure" Read more...
Book notes: The Manager's Path
Book notes on "The Manager's Path" Read more...
Book notes: The Pragmatic Programmer, 20th Anniversary Edition
Book notes on "The Pragmatic Programmer, 20th anniversary edition" Read more...
Book notes: Implementing Lean Software Development
Book notes on "Implementing Lean Software Development" Read more...
You dont believe in clean code
What has clean code ever done for us? Read more...
Image attribution:
Life of Brian by Monty Python
In case of doubt, ask for clarification
Your yearly reminder of why to use a clear and precise language and to ask to clarification when your teammates do not. Read more...
Book notes: No-Nonsense Leadership
Book notes on "No-Nonsense Leadership" Read more...
Virtual backgrounds for remote Software Developers
Must have backgrounds for all your remote meetings Read more...
Book notes: The Lean Mindset
Book notes on Mary and Tom Poppendieck's "The Lean Mindset" Read more...
Authorization service handover talk
A handover talk about a new internal authorization-related service. Read more...
Book notes: The Unicorn Project
Book notes on Gene Kim's "The Unicorn Project" Read more...
Expectations for GOTO Oslo conference
What can go wrong with a Clojure talk on a ship? Read more...
Book notes: Accelerate, building and scaling high performing technology organizations
Book notes on "Accelerate, building and scaling high performing technology organizations" Read more...
Software development and LEGO blocks
As easy as assembling LEGO blocks Read more...
Should I introduce an API Gateway in my workplace?
Considerations on when adding an API Gateway to your system architecture Read more...
Apache Http Client and Asynchronous HTTP client timeouts explained in pictures
Explaining with pictures what connection timeout, read timeout and connection pool timeout are, and how Apache HTTP Client compares to Asynchronous HTTP client when handling them Read more...
Book notes: Becoming a Technical Leader
Book notes on Jerry Weinberg's "Becoming a technical leader" Read more...
Java with a Clojure mindset
Video, transcript and slides from the Java2Days and Oredev 2018 talk Read more...
Architecture decisions: the belligerent contrarian and the rule of three
A couple of simple rules that have helped me on my years as a software architect. Read more...
Image attribution:
Image by geralt on Pixabay
Other reasons for TDD: Baby steps, ROI, Evil Manager Syndrome and Watching the watchmen
Describing some reasons to do Test Driven Development that are rarely mentioned. Read more...
Kodsnack podcast: The immediate feedback loop
Talking about Clojure, feedback loops and automation. Read more...
If I ever write a book ...
Programming like a Spaniard Read more...
RocksDB range queries in KafkaStream: dealing with big results
An example of when to use the RocksDB range query in KafkaStreams. Read more...
REPL driven development: immediate feedback for you backend code
Video, transcript and slides from the GeeCon 2018 talk Read more...
How to do a Java/JVM heap dump in Kubernetes
A simple task that is a little bit of a headache on Kubernetes Read more...
How to convince your company to use Clojure
The definitive video that will convert anybody to Clojure Read more...
In KafkaStreams, when to choose between a KTable or a KStream?
An example of how to choose between a KafkaStreams' KTable or KStream when doing stateful streaming transformations Read more...
Kubernetes explained in pictures: StatefulSets, Persistent Volumes and Headless Services
Explaining Kubernetes StatefulSets, Persistent Volume and Headless Services using KubePark's cloakroom service. Read more...
Kubernetes explained: the theme park analogy: auto scaling, taints and affinities
More on explaining Kubernetes and theme parks: scaling, taints and affinities. Read more...
Kubernetes explained in pictures: the theme park analogy
This is an attempt to explain Kubernetes core concepts (pods, nodes, services, resources, ...) with an theme park analogy. Read more...
Habits of efficient developers - WeAreDevelopers 2018
Video from my presentation on WeAreDevelopers 2018 on habits of efficient developers Read more...
A more efficient developer: Go and have a rest
Coffee is good. Sleeping is great. Read more...
Per user rate limiting with OpenID connect and Istio in Kubernetes
How to do rate limiting with Istio on Kubernetes a per user basis, using OpenID Connect to identify it. Read more...
Image attribution:
Photo of The Queues by Mark Walley.
Habits of efficient developers - slides
Slides for the "Habits of efficient developers" talk at WeAreDevelopers 2018 Read more...
Did you read my email?
Is it urgent? Read more...
Kafka, GDPR and Event Sourcing
Proof of concept for compliance with GDPR on an Event Sourcing architecture built with Apache Kafka. Read more...
Image attribution:
Modified from "He Wasn't This Angry" by Allison Mickel is licensed under CC BY-NC-SA
Kafka, GDPR and Event Sourcing - Implementation details
Implementation details for a proof of concept for compliance with GDPR on an Event Sourcing architecture built with Apache Kafka. Read more...
Kafka, distributed coordination and the actor model
On how to design KafkaStream applications in terms of the actor model. Read more...
Production data never lies
Using production data to automatically generate Avro schemas, using Spec-Provider. Read more...
Image attribution:
Photo of Pinocchio from Pexels.
Easing open source contributions with Docker
Software installation instructions sometimes look like IKEA assembly instructions and are as difficult to follow as those. Read more...
Image attribution:
Akvo’s open source badge, designed by Thomas Bjelkeman-Petterson and Anke van Lenteren
How to Docker Compose a developer environment: an open source example
An efficient team needs to have an easy way of setting up a development environment. This is a detailed example of how to do it. Read more...
Swagger Search: Finding an endpoint in your microservice primordial soup
An open source tools to find endpoints in a microservice architecture. Read more...
Why to Docker Compose a calm environment
Setting up or upgrading a developer environment should be an easy and repeatable process. Docker Compose is the tool to achieve it. Read more...
Applying stability patterns: a case study - Devoxx PL 2017
Video from my presentation on Devoxx PL 2017 on stability patterns Read more...
A more efficient developer: write programs for yourself
The shoemaker's son always go barefoot. Read more...
Image attribution:
English proverbs center
A more efficient developer: master your IDE
A professional developer should look professional while using his main tool. Read more...
Image attribution:
Wax on, wax off - Master Miyagi, The Karate Kid
A more efficient developer: disable notifications
How to become X times more efficient in one simple step. Read more...
Error budget: Google's solution for innovating at a sustainable pace
New features always trump technical work. Can we objectively measure and decide when they should not? Read more...
Image attribution:
http://www.wallpapervortex.com/
Atoms, delays and side effects: a resource management idiom for Clojure
Concurrency in Clojure is easy peasy, unless you have to deal with side effects. But atoms and delays can still help us. Let's look at an idiom for resource management. Read more...
Image attribution:
http://www.renegadejuggling.com
Delay: Clojure's forgotten concurrency primitive
When talking about Clojure's concurrency primitives, we often forget "delay". Let's see how it can help us. Read more...
Image attribution:
Scott Wolfe Jr
Testing or Monitoring? MTBF or MTTR? Make your choice!
What is more important testing or monitoring? Should you optimize for mean time between failures (MTBF) or mean time to repair (MTTR)? Read more...
Image attribution:
Baby, You Knock Me Out, Family Guy
Clojure's most important lesson
Clojure has a lot of important and unique lessons to teach, but which one is the most important? Read more...
Image attribution:
Consultant shows Clojure code sample to VBA team via @progpaintings
Automating resilience testing with Docker and Property Based Testing - Devoxx UK 2017
Video from my presentation on Devoxx UK 2017 on Docker, resilience and property based testing Read more...
Joins on stateful stream processing using Kafka Streams' KTables and GlobalKTables
Exploring different options in Kafka Streams to join KTables, both with and without shared keys. Read more...
Documenting your architecture: Wireshark, PlantUML and a REPL to glue them all.
Instead of drawing UML diagrams, why not generate them from a network traffic capture of the running system? Read more...
Kerberos explained in pictures
Kerberos is a single sign on authentication protocol, we will try to explain how it works with some hopefully simple diagrams. Read more...
Proof of concept using KafkaStreams and KTables - implementation notes, gotchas and Docker Compose example
Implementation details from a proof of concept using Kafka Streams and KTables using Clojure and Docker Read more...
Proof of concept using KafkaStreams and KTables
Exploring how to use KafkaStreams and KTables for building a stateful stream processing application Read more...
Why Java? Why Clojure?
The reasons to use Java and Clojure are the same Read more...