HTML Over the wire

PyWeb-IL 101

Relevant background for this talk

Developer > 35 years

Multiple languages, frameworks, paradigms

Work with most of the tools mentioned below

Handled frameworks, tooling & testing migrations

Frontend's lost decade

Tweet about frontend's lost decade

Yep, an opinionated and philosophic rant

Javascript 😠

In the old days (some goes into today):

  • No stdlib
  • No standard import mechanism
  • Global scope by default for variables
  • Wonky numbers handling (integers >253)

Thus leading to

  • Relying on lots 3rd party libs (like lodash, moment/day.js)
  • CommonJS and ES Modules
  • Ever increasing downloaded code size


  • New features not supported yet, Babel and friends
  • TypeScript will save us
  • OMG, we need ....

Build Tools

Grunt & Bower
Gulp & Browserify

Give me Interactive

Yay! we got AJAX

Users can't wait for full page refresh


JQuery & Mootools FTW

But we need it to resemble an application


SPA, yeah baby

Please make it stop


Yep, we got it, now what?


Need to validate both on client side and server side

Duplicate code and effort


Needs to support the SPA

Ends up matching app needs instead of proper REST

Often need multiple queries to serve a single UI function

GraphQL FTW? N+1, needs more complex tooling, heavier load on the backend


What do you mean no SEO?




Hmm, need to manage state and app data

Redux, Mobx, Vuex (past), Pinia (present)

What happened to the URLs?

Can't share links

Need to implement a routing solution

Representing all the options via Router and re-usable links is a hassle

Broken navigation (back button)

Leading to

Bought the wrong thing for a Christmas gift because the URL

Yep, he's the co-author of React Router

Down the Rabbit hole

  • A solution introduces additional problems
  • Which require other solutions
  • Faster churn
  • Harder to start for new developers
  • Complex tooling and DevOPS
  • Separate & larger teams
  • Impedance mismatch - Synchronize between them

Complexity, Hulk Smash

Hulk smash Puny God

Over the years I've learned to value simplicity

The Grug Brained Developer

Revolutionary Idea:

What if HTTP actually served HTML?


  • Easy to get started
  • Utilizes your existing backend stack
  • No need for separate or larger teams
  • Reduce the need for additional tooling

State of mind

Think of breaking the page to parts/partials

On some action, do an Ajax request

Replace parts of the page with returned HTML content

The secret sauce?

Combined with Alpine.js, Stimulus or Hypermedia


My favorite of the 3, choose your poison

Turns AJAX, CSS Transitions, WebSockets into declarative HTML attributes

Quick start

<script src=""></script>
<!-- have a button POST a click via AJAX -->
<button hx-post="/clicked" hx-swap="outerHTML">
  Click Me
  • When a user clicks on this button
  • Issue an AJAX POST request to /clicked
  • Replace the button with the HTML response

See examples

Some Kool-Aid

Executive Summary

  • Took ~2 months (from 21K LOC, mostly JS)
  • No reduction in the application's UX
  • Reduced the code size by 67%
  • Reduced total JS deps by 96% (255 to 9)
  • Reduced web build time by 88% (40 sec 5)
  • First load time-to-interactive was reduced by 50-60% (from 2 to 6 seconds to 1 to 2 seconds)
  • Much larger data sets were possible, react couldn't handle the data
  • Web app memory usage reduced by 46% (75MB to 45MB)

Some Python Resources

OK Boomer, now what?

Not suggesting abolishing FE frameworks

Think are they really needed?

Be aware of inertia based decisions


Questions? Comments?