Hi Effecters!
Welcome back to This Week In Effect (TWIE) - your weekly update of the latest developments in the Effect community and ecosystem.
Effect is a powerful TypeScript library that helps developers create complex, synchronous, and asynchronous programs. One key feature that sets Effect apart is how it leverages structured concurrency to provide features such as async cancellation and safe resource management, making it easier to build robust, scalable, and efficient programs.
To get started, below you’ll find links to our documentation as well as our guide for installing Effect. Enjoy!
Recent major updates:
- Cause & Effect Podcast with David Golightly: A Voice AI Orchestration Layer with Effect & TypeScript.
- Durable workflows in TypeScript with
@effect/workflow. - The Effect community on Discord reached 4500+ members!
Technology
Giulio Canti shared some sneak peeks of the upcoming Effect Schema v4:
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default
JSONSerialization / Deserialization -
invert a schema’s direction with
Schema.flip:🆕 Schema now supports default JSON serialization / deserialization. Perfect for RPC and messaging systems: no need to define your own format — just serialize + deserialize across the wire.
🆕 One of the most requested features in Schema v3 will be available in v4: flipping schemas. You can invert a schema's direction with `Schema.flip`.
Here are all the technical changes from the past week.
Effect Core
- Fix cron tests (Bug Fix)
- Fix Effect.filterOrFail return type inference (Bug Fix)
- Allow Multipart configuration in HttpApiSchema.Multipart (Feature)
- Relax Predicate.compose constraint on second refinement (Improvement)
- Remove global state index by version, make version mismatch a warning message (Feature, next-minor)
- Add Effect.ensure’Success,Error,Requirements’Type (Feature, next-minor)
Effect AI
- Expose system option in AiChat constructors (Improvement)
Effect Cluster
- Use FIFO queue for shard assignment, to reduce churn (Optimization)
- Allow for namespacing rpcs using a group.method convention (Improvement)
- Propagate fiber refs to workflow activities (Improvement)
- Fix unwrapping of DurableDeferred results (Bug Fix)
Effect Platform
- Allow Multipart configuration in HttpApiSchema.Multipart (Feature)
- Correctly propagate fs.watch errors when the stat fails (Bug Fix)
- Add HttpApiClient.makeWith, for supporting passing in HttpClient with errors and requirements (Feature)
- Docs: remove unused import in HttpServerRequest example (Documentation Update)
Effect RPC
- Allow for namespacing rpcs using a group.method convention (Improvement)
- Add flatten options to RpcClient constructors (Feature)
Effect Opentelemetry
- Add option to exclude log spans from OtlpLogger (Improvement)
General Chores
Cause & Effect Podcast Episode #3
A Voice AI Orchestration Layer built with Effect & TypeScript.
In this episode, Johannes Schickling sat down with David Golightly, Staff Engineer at MasterClass, to explore how his team built Cortex – a real-time voice AI orchestration layer that powers personalized conversations with celebrity instructors like Gordon Ramsay and Mark Cuban.
Cause & Effect features stories from software engineers and companies that use Effect in production. Each episode explores their journey of adopting Effect, including the learning process, challenges faced, and benefits of integrating Effect into their tech stack.
The podcast is hosted by Johannes Schickling and available on YouTube, X(Twitter), and audio platforms like Spotify and Apple Podcast.
Community Highlights
- Effect was trending on GitHub this week! 📈🚀
📛 effect 🧠 Effect is a TypeScript monorepo offering a framework for creating sturdy applications with a functional effect system and multiple support packages. 🛠️ @EffectTS_ 💻 TypeScript ⭐ 9648 🍴 340 🔗 github.com/Effect-TS/effe…
- Matt Pocock started exploring Effect, sharing its capabilities and the value it brings to the TypeScript ecosystem. We’re excited to see what he’ll share next.
Effect looks weird because it's doing more than you think
I've never seen better support for making code testable than in Effect Effect.flip lets you ensure that a function fails, and gives you the failure. Beautiful
- New video from Lucas Barake: Building an App with Effect | #1: Your First Server
- John A De Goes is looking for A TypeScript API designer - nominate someone or apply yourself.
I designed leading OSS libraries in the Scala ecosystem, which inspired @EffectTS_ & countless clones. 🚀 Now I am hunting for a brilliant API designer in the @typescript ecosystem for a paid & HIGHLY visible event coming soon. 👀 Nominate your favorite TS wizard below! 👇
- An example of deploying Effect Cluster to your AWS account with SST.
Releasing an example of the simplest way to deploy @EffectTS_ cluster to your AWS account in a highly scalable way with @SST_dev with great DX - Minimal Config - Local dev mimics production - Just Works™ Heavily inspired by @marcelohbairros (ty) Repo below 👇
- Use Effect AI to generate a schema, by Harry Solovay.
Effect Metaschemas. Use Effect AI to generate a schema. Use that schema to generate a value.
- Mattia Manzati will be talking at SquiggleConf 2025 in Boston on September 18-19th.
🌟 Speaker Spotlight: Mattia Manzati, founding engineer @EffectfulTech @MattiaManzati's talk is: "Effect: Type-Safe Errors and Dependency Injection" You’ll leave armed with a vision of the next-generation devtools support that makes squiggles your friend—not your foe. Hello,
effect-memfs– an in-memory file system in Effect for mocking, testing, and simulating files.
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Dillon Mulroy livestreamed three episodes of his new series Implementing RFC-1035 (DNS) with EffectTS 🚀.
Effect Content Update
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All Effect Days talks are now available on YouTube!
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Fixing auto-imports in your Effect code with the Effect LSP.
Tired of messy auto-imports in your Effect code? Every time fixing auto-imports manually... 😵💫 This quick video shows how the @EffectTS_ LSP can make it seamless and automatic. 👇
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Maxwell Brown livestreamed three episodes of his series, Building Stuff with Effect.
Hacking on some Effect stuff this morning - come hang out! twitch.tv/minbadblue
Effect Job Opportunities
More and more companies are adopting Effect in their projects. Here’s a list of companies looking for software engineers with Effect experience:
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Expand.ai: Founding Engineer
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Platonic Systems: Remote Effect Engineers
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Medbill.ai: Founding Software Engineers (full-stack and backend)
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Oneiro Solutions: Software Engineer - Core Team. Join Effect Discord and DM leighman for further info.
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Microsub: TS Developer
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Samsung Food: Full Stack Developer
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Margins: Product Engineer
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Precurion looking for a remote‑first Founding Engineer with Effect experience. The job posting is available in the
#job-boardchannel on our Discord. -
Vitalize is hiring a full-stack engineer with Effect experience: Full-Stack Engineer
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Embedded Insurance is hiring for a Senior Software Engineering position.
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Betalyra, an AI consulting company from Portugal, is looking for a part-time freelance software engineer (TypeScript/Effect) with AI experience. The job posting is available in the
#job-boardchannel on our Discord. -
Software Intelligence Works: Senior Full-Stack Engineer
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14.ai: Founding engineer
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Wander is hiring Software Developers with experience in Effect.
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Stealth team looking for a software engineer with Effect experience. The job posting is available in the
#job-boardchannel on our Discord. -
A French-speaking startup team led by Stephan Le Dorze is looking for a freelancer to join them - see his LinkedIn post for more details.
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Freckle.io is hiring Platform Engineers with experience in Effect.
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A stealth team that has already scaled their product to 50K daily active users in the last year, is looking for Effect Developers. DM wireless on X for more info.
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Job opening for Japanese-speaking developers
Disclaimer: Please note that these job postings are shared for informational purposes, and we encourage applicants to verify details directly with the hiring companies.
Effect Merch Store
In December 2024, we unveiled the Effect Merch Store with a selection of Effect-branded items designed for the community. All orders are processed through Printful.
Effect Merch is here! We’re excited to announce the launch of our Effect merch page! Grab your favorite swag & show your love for Effect in style! 🧢 effect.website/merch
Closing Notes
That’s all for this week. Thank you for being a vital part of our community. Your feedback is highly valued as we fine-tune this format. Feel free to share your thoughts, and we’ll do our best to tailor it to the needs of our community.
Effect Community Team