Vou contribuir com algumas que faltam:
.NET: https://telegram.me/dotnetbr
Angular: https://t.me/AngularBrasil
Analise Forense: https://telegram.me/ForenseBrasil
Arch Linux: https://t.me/archlinuxbr
Azure: https://telegram.me/azurebrasil
Linux: https://t.me/BrasilLinux
C/C++: https://telegram.me/ccppbrasil
CSS: https://telegram.me/cssbr
Cake PHP: https://telegram.me/cakephpbr
Code Igniter: https://t.me/CodeIgniterBr
Cyber Security: https://telegram.me/cybersecbr
DBA: https://telegram.me/joinchat/BSo6ET1rO4Ba2eSOHyMhGg
Dart: https://telegram.me/dartbrasil
Debian: https://telegram.me/debianbrasil
DevOps: https://telegram.me/devopsbr
Docker: https://telegram.me/dockerbr
Electron.js: https://telegram.me/electronJs_BR
Elixir: https://telegram.me/elixirbr
GraphQL: https://telegram.me/GraphQLBrasil
Kafka: https://t.me/kafkabr
Mongodb: https://t.me/mongodbbrasil
MySql: https://telegram.me/mysqlbr
Nginx: https://t.me/NginxBR
PHP: https://telegram.me/phpbrasil
Postgre sql: https://telegram.me/postgresqlbr
Python: https://telegram.me/pythonflask
Ubuntu: https://t.me/UbuntuBrasilOficial