Tim Retout

Qualifications

• AWS Certified Solutions Architect - Associate
• Google Cloud Certified - Professional Cloud Architect
• TOGAF® 9 Certified
• BCS Certificate in Enterprise & Solution Architecture (Intermediate)

• AWS Certified DevOps Engineer - Professional
• Google Cloud Certified - Professional Cloud Developer
• Certified Kubernetes Administrator (CKA)

• AWS Certified Security - Specialty
• Google Cloud Certified - Professional Cloud Security Engineer
• Certified Information Systems Security Professional (CISSP)

• ITIL® Foundation Certified

Experience

Organizations

Blog Posts

seL4 on Raspberry Pi 3 in AArch64 mode

Several references exist that document how to run seL4 on the Raspberry Pi 3 in 32-bit mode. One annoying paper cut encountered when getting this working is the need for a custom u-boot - either a binary distributed by the authors of seL4, or reverting a particular commit in u-boot. A recent release of seL4 mentioned AArch64 support for RPi3. I’ve got it running, and it appears to avoid the need for a custom u-boot. …(more)

• sel4
• rpi3
• arm

May 11, 2020

Lockdown

It seems right that I should mention the pandemic on my personal blog; I doubt very much that I will say anything original or interesting, but it would seem strange to look back on my writings from 2020 and see nothing about COVID-19. I had to check this, but I have been staying at home since Monday 15th March, save for occasional walks around the park. (UK schools closed on 20th March, and we officially announced the lockdown on 23rd March, but our house started a bit early due to having a mild cough. …(more)

• life

May 6, 2020

2020

Life comes at you fast. Since changing jobs three months ago, I have earned several cloud-related certifications, and started an assignment as a cloud security architect with a large financial services client. Consulting is quite different to ordinary employment; a great deal of emphasis is placed on making connections, and building a personal brand. I’m enjoying the variety of work, and the opportunity to develop my skills. My focus this year is on learning; I intend to spend more time reading and writing, especially as a way to distill and clarify my ideas. …(more)

• life

January 2, 2020

PA Consulting

In early October, I will be saying goodbye to my colleagues at CV-Library after 7.5 years, and joining PA Consulting in London as a Principal Consultant. Over the course of my time at CV-Library I have got married, had a child, and moved from Southampton to Bedford. I am happy to have played a part in the growth of CV-Library as a leading recruitment brand in the UK, especially helping to make the site more reliable - I can tell more than a few war stories. …(more)

September 4, 2019

My Free Software Activities for Jan/Feb 2019

I have done a small amount of free software work! However, I’m going to cheat and list it since the start of the year. Social groups First, the fun stuff: I organised the first two meetings of the Bedford Linux User Group. Fire engines were observed on both occasions, but this was pure coincidence. I sent pull requests adding a fancy map to the new lug.org.uk site. I need to follow up to make that mobile-friendly… apt security I sent PRs to whydoesaptnotusehttps. …(more)

February 28, 2019

Blog Migration

This evening I’ve migrated my blog to Hugo, and made it look a bit prettier. I apologise if I’ve broken any links - in particular, I don’t think listings of blog posts in a particular day or month are working. …(more)

February 27, 2019

Tokenizing IT jobs

One size does not fit all when it comes to building search applications - it is important to think about the business domain and user expectations. Here's a classic example from recruitment search (a domain which has absorbed six years of my life already...) - imagine you are a candidate searching for IT jobs on your favourite job board. Recall how a full-text index works as implemented in Solr or Elasticsearch - the job posting documents are treated as a bag of words (i. …(more)

• solr
• search
• parsing

May 29, 2018

Jenkins milestone steps do not work yet

Public Service Announcement for anyone relying on Jenkins for continuous deployment - the milestone step plugin as of version 1.3.1 will not function correctly if you could have more than two builds running at once - older builds could get deployed after newer builds. See JENKINS-46097. A possible workaround is to add an initial milestone at the start of the pipeline, which will then allow builds to be killed early. (Builds are only killed early once they have passed their first milestone. …(more)

• jenkins

August 14, 2017

Packet.net arm64 servers

Packet.net offer an ARMv8 server with 96 cores for $0.50/hour. I signed up and tried building Libreoffice to see what would happen. Debian isn't officially supported there yet, but they offer Ubuntu, which suffices for testing the hardware. Final build time: around 12 hours, compared to 2hr 55m on the official arm64 buildd. Most of the Libreoffice build appeared to consist of "touch /some/file" repeated endlessly - I have a suspicion that the I/O performance might be low on this server (although I have no further evidence to offer for this). …(more)

• debian

April 25, 2017

Happy New Year!

Happy New Year! Apparently I failed to write a blog entry in all of 2016, and almost all of 2015. Probably says something profound about the rise of social media, or perhaps I was just very busy. I bet my writing has suffered. I have spent the last few days tidying up and clearing out clothes, bits of paper, and wires. I think there's light at the end of the tunnel. …(more)

• life

January 1, 2017

More Blog Posts »