Mental models of on-call

Written on 01 Sep 2023, 5 min read.

The mental models in our heads shape every discussion. Understanding how they align or differ between participants in a conversation is an important aspect of effective communication. This is particularly relevant for topics such as on-call where a wide range of different experiences lead to strongly held opinions. This post steps back from high-level discussion of the opportunity on-call offers to focus on describing two key mental models I use to think about on-call and the roles and responsibilities of the different people involved.

On-call is an opportunity

Written on 16 Aug 2023, 8 min read.

For an audio conversation covering similar themes, check out my interview on the Slight Reliability Podcast. On-call in software teams has a bad reputation. Niall Murphy’s 2018 polemic, Against On-Call is well worth a watch if you need a refresher on the many reasons why the reputation is justified. Despite the current reputation, on-call can and should be an activity that every software engineer participates in and finds some measure of fulfilment from.

Designing a PCBA friendly CO2 monitor

Written on 27 Jun 2023, 13 min read.

co2mon.nz currently uses monitors based on Oliver Seiler’s open source design which I am personally building. This post describes my exploration of how to achieve production of a CO2 monitor that could enable the growth of co2mon.nz. Goals Primarily I want to design a CO2 monitor which allows the majority of the production process to be outsourced. In particular, the PCB should be able to be assembled in an automated fashion (PCBA).

Ventilation Monitoring Market Research

Written on 14 Jun 2023, 7 min read.

Over the last month I’ve performed some market research to better understand the potential for co2mon.nz and to help me decide whether the product I’ve built has a fit with the market or not. The key conclusions I’ve drawn from this work are: Air quality is acknowledged as important, but monitoring it is not an urgent or pressing problem for most people. Most of the value is seen in the hardware rather than the software service.

Calling time on DNSSEC

Written on 02 Jun 2023, 11 min read.

I’m calling time on DNSSEC. Last week, prompted by a change in my DNS hosting setup, I began removing it from the few personal zones I had signed. Then this Monday the .nz ccTLD experienced a multi-day availability incident triggered by the annual DNSSEC key rotation process. This incident broke several of my unsigned zones, which led me to say very unkind things about DNSSEC on Mastodon and now I feel compelled to more completely explain my thinking:

co2mon.nz

Written on 18 Apr 2023, 7 min read.

Previously, I explained why ventilation monitoring is important, and the opportunity I see to help accelerate deployment of high quality ventilation monitoring for small businesses and organisations. In this post, I’m going to discuss my plans to tackle that opportunity: My journey to ventilation monitoring co2mon.nz: Ventilation monitoring as a service prototype Areas of development Next steps My journey to ventilation monitoring I started looking into ventilation monitoring in detail last year when I wanted to ensure that the classrooms of our local primary school were well ventilated during the Omicron outbreak.

Ventilation Monitoring

Written on 28 Mar 2023, 10 min read.

The importance of clean, fresh indoor air is one of the most tangible takeaways of the Covid-19 pandemic. In addition to being an effective risk mitigation strategy for reducing the spread of respiratory illnesses, clean, fresh air is necessary to enable effective cognitive performance. Monitoring indoor air quality is relatively easy to do, but traditionally has not been a key focus. I believe air quality monitoring should be accessible for any indoor space, and for highly occupied indoor spaces should be provided on a continuous basis.