jsday 2025
2025-04-07..2025-04-08
-- online --
jsday ·
[jsDay 2017, jsDay 2018, JSDay 2019, jsday 2020, jsday 2021, jsday 2022, jsday 2023, jsday 2024, jsday 2025]
as the organisers put it
Browse the talk of jsday 2025 , the 14th edition of Italy’s premier JavaScript conference organized by GrUSP 👾 Main topics: Event Loop, Micro-frontends, Accessibility, TypeScript, Next.js, NodeJS., Copilot, AI, Feature flags, Performance, Lambda.
who it's for
JavaScript developers, frontend engineers, TypeScript developers, Node.js developers, accessibility engineers, web AI engineers, design system engineers
topics
React Native visual coverage; advanced TypeScript types; accessibility law compliance; AI for accessibility; privacy-first in-browser generative AI; Node.js platform changes 2025; serving Node.js binaries at scale; micro frontends architecture; Qwik deployment and optimisation; ahead-of-time JavaScript compilation; memory leak detection in JavaScript; frontend observability and tracing
| title | author | length |
|---|---|---|
| Oh S***! There's a New Accessibility Law and I'm Not Ready! | Emma Dawson | 32m |
New European Accessibility Act brings a June 28th deadline and the checklist is specific: adopt semantic HTML instead of divs-for-everything, swap custom… | ||
| Design System Visual Coverage in React Native applications | S. Magni, M. Ronchi | 32m |
A library counts rendered pixels to report a single coverage percentage and ships as plain JavaScript that runs in production counting pixels. It builds a… | ||
| Think you know TypeScript? Think again. | Giuseppe Funicello | 22m |
Claims concrete tactics: replace any with unknown and add explicit guards, write type predicates for narrowing so variables truly become strings or numbers… | ||
| Accessibility powered by AI | Ramona Domen | 32m |
Claims that AI will replace accessibility work give context but not solutions instead the talk shows concrete experiments using GPT-3, ChatGPT and Github… | ||
| Elegant by Design: Javascript in Javascript | Paolo Caressa | 43m |
Claims that JavaScript is elegant by design because it implements itself and shows a simple JavaScript self-implementation: a hand‑written scanner, a… | ||
| Let’s build K.I.T.T. with JavaScript | Nico Martin | 30m |
Builds a browser K.I.T.T. using JavaScript that actually runs offline and claims privacy by default, combining transforms.js + Whisper + kakoro for speech… | ||
| Developing Resilience | Melinda Seckington | 45m |
Claims concrete techniques: a master’s thesis built an emotion‑recognition AI, resilience is an umbrella not a brick wall, and practicing emotional agility… | ||
| Privacy-first in-browser Generative AI web apps | Maxim Salnikov | 32m |
Live demo runs fully offline on a Surface Laptop with an NPU, hosted on Vercel, and shows image classification working with a visible CPU/NPU spike; model… | ||
| Micro Frontends, Five Years After | Max Gallo | 33m |
DAZN started a micro‑frontend rollout in 2019 and scales it to millions of users by mixing vertical microfrontends (full‑page, single‑team) with a few… | ||
| The State of Node.js - 2025 | Matteo Collina | 31m |
Node.js reports 30 billion downloads in 2024 and monthly package installs rise from 30M in 2021 to 60M in 2024, so usage grows not wanes. Recent shipping… | ||
| Revamping How Node.js Binaries Are Served At Scale | Claudio Wunder | 23m |
Node release assets now route through Cloudflare Workers + R2, replacing a single DigitalOcean origin and nginx with serverless edge logic. The system handles… | ||
| A Pattern for a Well-Knit JavaScript Project | Carmen Huidobro | 23m |
Upgrading a React Native app from 55 to 74 (almost 20 versions) breaks many things and gets fixed by incremental steps: use npm why to find who depends on a… | ||
| Conversations Without Prompts: AI in the Web | Andreea Miclaus | 32m |
Claims a working Grammarly‑style browser extension that injects highlights and a side panel to surface AI insights, built with content scripts, background… | ||
| What's Happening in the JavaScript Ecosystem? | Fabio Biondi, Giorgio Boa | 32m |
Front-end claims: Qwik ships HTML and CSS and 1 kilobyte of JavaScript via resumability using on:click-style optimizations instead of full hydration; Next.js… | ||
| Qwik Go For 100 | Wout Mertens | 30m |
Claim: Qwik automatically keeps Core Web Vitals high as an app scales by shipping only the tiny code needed for interactive nodes. It uses the Qwik optimizer… | ||
| Compiling JavaScript ahead-of-time | Oliver Medhurst | 07m |
Porffor compiles JavaScript ahead-of-time into WebAssembly and native executables, producing 20 kilobytes native and 4 kilobytes wasm example binaries, and it… | ||
| JavaScript is an Oddball | Massimo Artizzu | 34m |
Shows concrete tricks and limits: use Intl.Collator (or localeCompare with options) to sort mixed strings in one line and precreate a Collator for large lists… | ||
| The Cost of Abstractions | Massimiliano Mantione | 27m |
Benchmarks compare plain async TypeScript, an effects library, FPTS (old and newer), and Rust (native and WASM) on a 100,000‑order workflow with 5% failures… | ||
| Design a new language in JS: from zero to autocomplete | Marco Liberati | 26m |
Claims a workable pipeline: a PeggyJS parser generates an AST, three service APIs (evaluate, validate, autocomplete) run on top, and the whole thing embeds… | ||
| JavaScript is weird. MythBusters special | Małgorzata Janeczek | 32m |
Live demos run in a small demo web app that shows code, output and audience voting and mostly works despite some zoom problems. Examples show concrete quirks… | ||
| TypeScript Gymnastics: Why Are They So Powerful for You? | Luca Del Puppo | 35m |
TypeScript techniques get named and shown with working code: a parseUrlParams type that extracts route params at compile time powers a navigate(url, params)… | ||
| I Can't Believe It's Not JavaScript! | Jemima Abu | 31m |
Claim: reduce JavaScript dependency by replacing common widgets with native HTML/CSS and still get focus management, keyboard behavior and faster rendering… | ||
| What's new for the web platform | Gilberto Cocchi | 34m |
Coverage lists concrete changes: Gemini Nano runs locally via built‑in AI APIs, and Chrome exposes four origin-trial APIs (summarize, translate, detect… | ||
| Solving Real World Data Fetching Challenges: A Pragmatic Case Study | Faris Aziz | 29m |
A fintech case study reduces five parallel 1,000‑user API calls into a single Next.js BFF request and reduces payload from 2.3MB to 666 bytes (≈99.9%)… | ||
| Memory Leaks in JavaScript | Daniel Danielecki | 31m |
Shows how to find and fix concrete leaks using MemLab and Chrome DevTools with live demos: creating 10,000 divs and taking heap snapshots that show a +1.2 MB… | ||
| Observability for Frontend Engineers | Carly Richmond | 32m |
Claims front-end observability still lags but is practical: instrumentation uses Elastic RUM agent for real user metrics (LCP, INP replacing FID, CLS), console… | ||
| Automate Your Life: Building a Workflow Engine in TypeScript | Alfonso Graziano | 26m |
Claims a runnable TypeScript workflow engine that actually enforces a DAG, stores templates and runs in Postgres, queues work on Redis and executes workers via… | ||
| nothing matches | ||