In response to the good @SubtleGradient, who recently asked [paraphrasing] will Effect-TS avoid RxJS’s “flash-in-the-pan” fate in the JS ecosystem? RxJS was an early solution to the challenges of async and reactivity. Gradually, aspects of this problem were solved by simpler, more imperative apis: React, hooks, react-query, async/await, etc. The Reactive Streaming paradigm has failed to really take off in any language—e.g., a few years back, Apple released its very own first class reactive streaming API called Combine, which was deprecated within a year, supplanted by a much simpler, more imperative API. It also doesn’t help that RxJS is inspired by Java’s Reactive Extensions, and thus its API surface area is circumscribed by existing, non-great Rx conventions. For whatever reason, however theoretically elegant, modeling everything as a reactive stream appears to suck (as objectively judged by the market). This inherent suckiness, combined with competition from more modern alternatives, has driven people away from RxJs. Now, with Effect, there isn’t anything in JavaScript that solves these same problems, let alone more simply. If you want resource safety, retries, log spans / annotations, typed errors, composable dependency injection, interruptibility, and all the other benefits derived from Effect’s programs-as-values design, you’ll either have to use Effect or roll your own much shittier ad hoc version, once per codebase. Promise isn’t really an alternative to Effect, as it merely provides barebones async support and none of the aforementioned capabilities. Once you’re reaching for AbortController, you’re doomed. The only true alternative is total acquiescence to a diminished quality of life: you won’t know all the ways your program might fail; parallel computations won’t be interrupted; retrying will be ad hoc and verbose; logging shmlogging; telemetry shmelemetry. The one convincing argument contra-Effect is that you just don’t need or want to solve these problems. In many apps, this might be fine, if you can tolerate a certain amount of pain and turmoil. Clearly, this approach works and can scale, it is indeed the approach of most companies. The question is: can it scale as fast, as far, and with as small of a team of developers? I’d reckon the difference is measured in orders of magnitude. In my experience, once you do get on board with Effect, understand what it offers, and acclimate to its syntactic idiosyncrasies, you could not possibly fathom going back. I imagine it would be like having an 18th-century doctor struck with a prophetic vision about Germ Theory before returning to his 18th-century operating room. He might then feel, justifiably so, that he was doing great harm to the people he was supposed to be helping.