Ask HN: How to find devs for feedback in London

I'm working on a new website builder, aimed at developers, and I wanted sit down with devs to get feedback (invite them for a coffee). I talked to almost every developer I know and they all loved it (subscribed for free beta), now I wanted to get feedback from strangers. I just moved to London for work so I barely know anyone here. I set out to talk to 100 strangers. With a pace of 1 stranger a week, it would take 2 years.

Any ideas would be great on how to shorten this time. If you are in London and would enjoy a coffee with me, that would be double great.