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Thoughts from day one of CLL19 as a first time speaker

I was fortunate enough to speak at Continuous Lifecycle London (CLL19) this year. It’s the first time I’ve ever spoken at a conference and I found it very rewarding.
In the past few weeks, I worked very hard preparing my talk. I had almost expected to be working on my slides solidly right up to the point of speaking. This is probably why I didn’t give much thought to the other talks that I might be able to attend.  On the day, I felt more prepared than expected and was able to watch some really great talks.
Here are some of the thoughts from my experience of the day.


Welcome message - Joe Fay
Joe introduced the event and explained that the committee had reviewed more than two hundred proposals and filtered it down to just thirty nine.  I hadn't realised there had been so many proposals so they just made me feel even more privileged to have been selected.  Around three hundred people were attending.

Key Note - Tanya Reilly - Squarespace
Tanya's keynote was fantastic and left …

Polling vs WebSockets - Part 2 - Stress Testing

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In my previous blog post, I discussed the efficiency of polling compared to WebSockets for a web application.  Using these two different implementations and performance tests, I decided it would be interesting to perform some stress testing to see which solution can handle the most load.

All code on github here.  For details of the original problem and performance tests, see here

Let's increase the threads until it fails
Even with a low number of threads, occasionally I would encounter errors - most likely soon after the server had started in its new Docker container.  Therefore I decided to run each scenario three times and display all results. Scenario - 40 ThreadsJob duration 0-10 seconds40 Threads/Users - Instant ramp upEach Thread creating 10 jobsPolling interval of 500msTimeout: 11 seconds Results - Some Errors from WebSocket implementationRun 1Polling - 0 errorsWebSockets - 0 errorsRun 2Polling - 0 errorsWebSockets - 2 errorsRun 3Polling - 0 errorsWebSockets - 0 errors
What…

Efficiency of Polling vs WebSockets

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A web application I maintain uses polling from the front end to check if a long running task is complete. A colleague suggested that WebScokets would be a far better alternative in terms of performance and user experience. Having never used WebSockets before and keen to see just how much better it could be, I decided to compare the two approaches to a contrived but similar problem side by side.

All code on github here.

The problem
My hypothetical problem involves jobs. Each job consists of:
a unique ida boolean named complete A job is created by a client of the application and after a random duration the job completes (i.e. complete = true). The client needs to know as soon as possible once a job is complete.  This can be achieved by the client polling a job's status repeatedly until complete, or receiving a "job completion" event once finished.

For both solutions I decided to use Kotlin and the Dropwizard framework. Both of which I'm familiar…

ASCII Art Mazes and Playing with Kotlin

I decided to play around with Kotlin for fun on a home project that interested me.  At many points during the development I was thankful that I was using Kotlin and not Java, here's a few notes that explain why.  All the code for this page can be found here: https://github.com/phillbarber/kotlin-maze-demo

The Problem Given a simple 2D maze inputted in an "ASCII art" format, write some kotlin code that will plot a route from the Start to Finish.

In other words, given this...

############################################ # # # # # # # # # # # # # # # # # # # # # # # F # # # # # # # # …

From Developer to Product Owner

I have been a software developer for around ten years, but recently I was fortunate enough to be offered a different role as product owner (PO) for an Identity Platform. Keen to try something new, I accepted. However, after seven months in the role, I worked out that it wasn’t for me. This post will detail what went well, what went badly and what other developers can possibly expect if they choose to make the switch from engineering to product.


My background I have been a developer ever since my Uni days and have worked at a number of different companies in London for around ten years. I’ve worked for Media companies, Finance and also a startup.


The Job When I was contacted by a friend (and former colleague) about a “Technical Product Owner” role I was really intrigued. I have always felt that “pure development” roles don’t fit me perfectly as I enjoy more than just coding features. I enjoy coming up with plans, talking to a wide range of people in an organisation and taking on …