E-mail ✉️
me[at]solarchemist[dot]se
(I trust you to replace the brackets with the proper symbols).
On the Fediverse
Follow or message me at either of these Mastodon accounts (whichever suits you best).
Matrix chat
Get in touch with me on the federated Matrix protocol:
@solarchemist:matrix.org
Signal chat
Message me: solarchemist.03.
Other services
If none of the above suit you, you could give one of these a try (but please note that I don’t check these services very often):