Learn Farsi: من مالیات را از طریق درگاه جدید سامانه پرداخت کردم. - I paid the tax via the new portal of the system.

The phrase az tarigh literally means "by way of" or "through the path." To connect it to the noun that follows, it must take an ezafe connector (the invisible "e" sound). So, it becomes az tarigh-e dargāh (via the portal).

Why is there such a long chain of ezafe connectors in az tarigh-e dargāh-e jadīd-e sāmāneh?

The ezafe is doing three different jobs here! First it links the formal preposition az tarigh-e to the noun. Then, the noun dargāh (portal) takes an ezafe to link to its adjective jadīd (new). Finally, the adjective takes another ezafe to link to the "owner", sāmāneh (system), creating "via the new portal of the system".

Is sāmāneh the most common word for "system" here?

Yes, specifically for online platforms, software, and government websites. While people often use the loanword sistem in everyday speech for general systems, sāmāneh is the standard, formal term you will see on official websites and portals.

Why does māliyāt (tax) need the marker rā?

Because it is a specific direct object. The speaker isn't just saying "I paid taxes" generally; they are saying "I paid THE tax" (a specific bill they owed). Whenever a direct object is definite and specific like this, it must be followed by the object marker rā.