How I helped ~6,000 Australians find a vaccine appointment

In mid 2021 Australia had an acute vaccine shortage for various reasons, which meant vaccine appointments were extremely hard to come by – NSW had just declared a national emergency.

To help Australia increase it’s vaccination rate ASAP I built over a few weekends in July/August, an open-source (on Github) vaccine appointment search engine, as a side project.

As of Jan 2022, 23k users visited the site, and 5,809 unique users started a HotDoc vaccine booking after using my site!

After the shortage eased in October 2021 and the government booking website improved traffic dropped off, but here is the story of how I built it!

I promise it looks good on mobile too! See

Wanting to help Aussies get vaccinated as soon as possible, I searched for every possible data source (and considered crowd-sourcing phone call responses). I found that HotDoc (a Melbourne healthcare booking company) had lots of data on available bookings but had not yet built a way to search across clinics for the soonest appointments.

Always keen for a side project I managed to deploy a headless Chromium instance to AWS Lambda to walk through GPs near the user and find appointment times, and soon had a working demo. As you can imagine, I was concerned about the load this would add to the HotDoc site and resources to run it so I added strong rate limiting, but it’s hard to emphasize how in demand vaccines were at the time – I had friends asking me via social media to run queries for their location!

After posting on Reddit and sharing with a few friends, almost 2800 people visited on the first day. The most requested feature was searching by postcode rather than geo-location: once I implemented that I found most users preferred using that option. The Pfizer vaccine also became available via GPs which further added to the surge of visitors.

I got in contact with a friend of a friend working at HotDoc so I could make sure they were comfortable with myself using their data and API.

They were happy with the project and agreed my rate limiting threshold was well chosen, and submitted a PR so they could track referrals. Altogether the experience of communicating with HotDoc was excellent – they also emphasised how committed they are to helping Australians access vaccines.

After vaccines became more widely available visitors dropped off, though a smaller second wave visited when I added booster search support.

All up

Overall this was one of my favourite side projects I’ve built – it was a lot of fun to try and throw my hat in the ring to make this problem a bit easier to solve. It really meant a lot to me that I managed to help a few people in the process. Thanks for reading!

I think it’s important to acknowledge the number of people who used pales in comparison to how many people found their vaccines using HotDoc itself – they’ve built a truly brilliant product.

Ken Tsang (the author of COVID-19 Near Me) also wrote up an article about his vaccine booking search engine titled “Why I decided to build my own vaccine booking search engine instead of using the Government’s one”.

Currently, a side project I’m working on is Gatho (, a platform for hosting small events. It supports one click RSVP links for guests, and can integrate with a Matrix group chat. It’s open source and works great, let me know what you think!

Some more graphs of, because everybody loves graphs!


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