atomic-render.js

const tag = (name, children)=> ({
  name,
  children: children.map ? children: [children]
});

const div = tag.bind(null, 'div');
const span = tag.bind(null, 'span');
const p = tag.bind(null, 'p');
const b = tag.bind(null, 'b');
const a = tag.bind(null, 'a');

const appendChildren = (el, children) => (
  children.map(render.bind(null, el)),
  el
)
  
const createEl = name =>
  document.createElement(name.toUpperCase())

const renderEl = tree =>
  appendChildren(
    createEl(tree.name.toUpperCase()),
    tree.children
  )

const renderText = text =>
  document.createTextNode(text)

const isElement = tree =>
  tree.name && tree.children
// <div id="stage" />

const renderTree = tree =>
  isElement(tree) ? renderEl(tree) : renderText(tree)

const render = (root, tree) =>
  root.appendChild(renderTree(tree))


const dom = div([
  p('olá mundo'),
  span([
    'teste: ',
    b('olá mundo')
  ]),
  a('link')
]);

render(window.stage, dom);

Esse code eh do mestre @halan https://jsfiddle.net/halan/yn5z77ay/