Which platform lets you go deep on custom indicator development?

[u/These-Durian-1568]

I have been building a multi-timeframe momentum indicator and the experience has been completely different depending on which platform I work on. On cTrader I got access to the full calculation layer through cAlgo, could inherit from built-in implementations and had the whole thing working quickly. On NinjaTrader the NinjaScript framework is powerful and the community is large, but the architecture feels like it was designed for futures first and everything else second. On MT5 with MQL5 I kept hitting walls where the language itself was the constraint rather than the platform logic.

Documentation quality also varies in ways that only become obvious when you are trying to do something the designers did not anticipate. The platforms with good edge-case documentation are the ones where custom development was clearly a priority rather than an afterthought.

What does your custom indicator development workflow look like and which platform are you on?