mymizu's Second Open Source Hackathon!

On 11th March 2023, we held our second mymizu Hackathon, co-hosted with our friends at Code Chrysalis. What an epic day!

Here's a summary of the hackathon and all of the cool new things we developed together, thanks to the power of the mymizu community.

But first, let's go back to basics. What exactly is a hackathon?

It's a fun event where software developers, including programmers and engineers, get together to develop and improve software quickly. The goal is to work intensely to see how much they can accomplish in a short amount of time!

For our hackathon, we focused on the improvement and development of new features for our mymizu web app, with the aim of helping even more people to refill with a reusable bottle instead of choosing single-use plastic.

Talented Developers from across Japan, united by one Mission.

We're happy to say that people of all programming levels, ages, and backgrounds joined us - some even came all the way to Tokyo from as far afield as Sendai and Osaka to join in the fun!

Last year, we launched our mymizu web app, which lets users access our water refill map on their preferred device, PC or tablet, without having to download the mobile app. It's based on an open-source model, which means anyone can add new features and improvements at any time.

Volunteers have already added several handy features, such as the ability to create URLs for mymizu Refill Partners (i.e. our partner stores) on the map.

But we know all too well that there are many other improvements we can make... And that's why we organised the hackathon; with the belief that together, we can level up the mymizu platform and get even more people refilling across Japan and the world!

From day one, we've believed that we can use technology and community to solve social issues, and our hackathon was a beautiful manifestation of this.

What did we achieve?

Thanks to the hard work of the talented participants, we managed to add or improve SEVEN new features in one day! This feat is made all the more remarkable when you consider the fact that most participants had never even met before.

After deciding on projects, breaking into teams, several hearty discussions, and many hours of joyous coding, each group gave presentations at the end of the day to show their work.

(Oh, and we all ate falafel for lunch - because who doesn't like falafel - and had a good time chatting with one another too).

The result? Four amazing new features.

1) Filter Function

Finding the perfect refill spot is now easier thanks to a very cool filtering function. You can narrow down the available spots by selecting the type of water - cold, hot, purified, or tap - and whether the refill spot is self-service or staff-supplied.

2) Geolocation

The aptly named "Geolocators" Team developed a feature to immediately locate the user (so that they don't have to input their address every time), as well as automatically show all nearby refill spots. Very handy!

3) Reduce Loading Time.

Loading time sucks...

That's why we were thrilled when one team spun some coding magic to reduce the time taken to load refill spots on the map.

4) Showing Love to Contributors

The mymizu web app has many fantastic contributors, and they deserve recognition!

Now, thanks to the cunning work of another team, contributors' names and Github accounts are listed on the web app too. Be sure to give them a shout-out!


Thanks to the many people involved, this mymizu community Hackathon was a roaring success.

We brought together like-minded people and co-created something that can help thousands of people around the world reduce their plastic consumption.

We received positive feedback, with everyone inspired by the atmosphere and energy of the event. 'Even programming beginners were able to participate,' one person said. Another mentioned: 'I was able to relax and work at my own pace, which was really great'.

The event wasn't just about technology, it was about connecting people through a shared passion for positive impact and creating a better future for all. We're committed to solving social issues through technology and community, and events like this are a vital part of achieving that goal.

If you missed out on the second hackathon, not to worry! There will be more opportunities to get involved, so make sure to check out our website and social media to find out about upcoming opportunities and events.

Thank you to our friends at Code Chrysalis for making this possible, and everyone who joined us - we hope you had as much fun as we did! See you at the next one☺️


Writer Profile: Hinako Sugiyama

Hinako is not your typical fourth-year university student. She's an avid traveler, expert knitter, and environmental champion.

A literature major studying "ecocriticism", Hinako will inspire you to look at the world through a different lens. On a sweltering summer day, Hinako realised that as a child, she never had to experience such high temperatures.

Feeling determined to make a change, she decided to take action herself and become part of the solution. At mymizu, Hinako plays an important role in our communications team, helping us to tell stories of impact created by our community.

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