Why everyone is talking about Effect

Sandro Maglione

Sandro Maglione

Web development

This week Effect exploded 🤯

Everyone took notice, and everyone is talking about it.

Both 😇

I’m a much better programmer today than I was 2.5 years ago, after 25+ years of programming and 12 professionally. Why? @EffectTS_ taught me to deeply care about problems I was underestimating, which all applications face no matter which language they’re written in.


and 🫤/🤔

This is exactly why I won’t be touching Effect for a long time. Buying into a new language or even mental model is not just a personal decision. It’s a team/company/ecosystem one. Just like React and TypeScript, I will resist adoption until the network “effects” become so…

Matt Pocock
Matt Pocock

My current mental model, which the maintainers might disagree with, is this: Effect should be treated like a new language, like Elm or ReScript, that happens to use TypeScript syntax. This language has a ton of benefits. Strongly-typed errors. Built-in handling of complex…


I have been using and talking about Effect for a long time now.

Here is my take, and why you should care about this "Effect" thing 👇

Why Effect in the first place?

In the heat of the discussion the main doubt about Effect remains: why?

The simple answer is: "it allows to easily create and maintain complex Typescript applications"

Indeed, that's a bit generic to sell the real value of Effect.

That's my take on "why Effect" 👇

Type safety

It's so awesome when you refactor some code and the complier guides you in all the places in your code that you need to update. That's the power of using types.


  • Adding a new error forces you to handle it in all the places where it's introduced (e.g. catchTags)
  • Adding a new services requires you to provide valid implementations where required (i.e. provide)
  • With the Match module and pattern matching you are required to handle all cases


Dependency injection built in allows to write generic and composable apps.

Define services, and then swap and compose different implementations. This makes testing a breeze, and allows to switch between one solution to another in 1 line of code

You are no more dependent on any framework or library. This is a huge plus 🚀

Best practices

Effect teaches you best practices (regardless of programming language):

The principles that Effect uses and applies force you to better structure and understand your code.

There is more.

Every week I build a new open source project, with a new language or library, and teach you how I did it, what I learned, and how you can do the same. Join me and other 700+ readers.

What will happen

The people who tried Effect and understood the "why" are now all-in on it:

This heat will increase more and more in the upcoming months as more people learn about it and start to share more examples.

The Effect team is also hard at work to provide more app examples and improve the docs:

I work on multiple production codebases that are using Effect. I am also going to share more and more examples in the near future:

Meanwhile, you can start from some of the articles I already published about getting started with Effect:

Effect is no more a bet 🔥

Using @EffectTS_ is one of these rare "high reward / low risk" bets: - if Effect fails, congratulations you’re now highly skilled at TypeScript and that’s still very valuable on the market - if Effect succeeds, congratulations you’re now highly skilled at both and very valuable


Now it's the time to start looking into it. My suggestion is to try it, see by yourself the problem that it solves, and share what you learn along the path.

I am doing the same 💁🏼‍♂️

See you next 👋

Start here.

Every week I build a new open source project, with a new language or library, and teach you how I did it, what I learned, and how you can do the same. Join me and other 700+ readers.