Anywhere you can choose what communities you do and do not interract with is going to be an echo chamber. Lemmy and all social media are echo chambers. We aren’t special.
Don’t take for granted the spaces that are not. I am a firm believer that a well-guided opinion must be bathed in scrutiny — which you are never going to get in an echo chamber.
As human beings we have a tendency to get defensive at the first hint of a challenge. I would urge others to be conscious of this and give yourselves space to consider these challenges to your ideas.
About a decade ago I worked for T-Mobile on a very similar product. I would be surprised if they used any security considering during my time there, they would commonly ship hackathon projects as-is.