Hi @mshadi and welcome to the forum 
I’m glad you are interested in contributing!
- The very first step would be to follow the build instructions: Build Collabora Online | Collabora Online - Community Page
- There are also a couple the Development Topic to keep an eye.
- There we post minutes of each Weekly COOL meeting
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Every Thursday -
~ 12:00 CEST (convert to your local time)
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Jitsi Meet
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- There are also other useful posts all around development. Example: First Pull request, Keep forked repo updated, JSDialogs, Get Android logs, Uno commands, etc
- There we post minutes of each Weekly COOL meeting
We also have newcomers meeting every morning at 10 CEST so that could be useful (same link as the community meeting)
We have all the easy hacks marked so you can filter them: Issues · CollaboraOnline/online · GitHub
https://sdk.collaboraonline.com/ is where documentation lives together with README files in the repository itself
Oh, and please feel free to join our chat channel:
- The #cool-dev IRC channel is located in the Libera.chat server. The channel is currently bridged to both Telegram and Matrix.
- Chat with IRC via Libera.Chat and /join #cool-dev channel
- Chat via Matrix and join #cool-dev:libera.chat: https://app.element.io/#/room/#cool-dev:libera.chat
- Chat on Telegram and join CollaboraOnline: Telegram: Contact @CollaboraOnline