Pros
Sinam seems to be the best starting point for many junior software developers in its country. Sinam has very interesting and useful projects, so that developer can enhance his/her knowledge and skills.
Sinam has many experienced developers, which can be your mentors during development.
Sinam has a lot of events where developers gather together to share their knowledge.
Kontras
Not much I can say about cons. Seems that there is no big teams (more than 5-6 people) of developers for a project, even if the project is big.