Migration to Micro-Frontends

The short version

Dunelm's website was one enormous piece of code that every team had to share. I was part of the team that broke it into independent pieces, so each team could release its own work without waiting for anyone else. Releases went up roughly threefold and the site got faster for shoppers.

What was at stake

For a retailer this size, the website is the shop. Every week a change sat in a queue was a week of improvements customers never saw — a better checkout, a clearer product page, a fixed fault on a category listing.

The deeper problem was cultural. When releasing is risky, people batch changes up to reduce how often they do it, which makes each release bigger and riskier still. The team was stuck in that loop.

Splitting the site into pieces

Rather than rewrite everything at once — expensive, slow, and a genuine risk to trading — we carved the site up gradually. Parts that appear on every page came out first: the header, the footer, and the shared components everything else is built from.

Each piece became something a team could work on, test and release by itself. A change to the header no longer meant touching the code that runs the basket.

Keeping the shop open while rebuilding it

The old site kept trading throughout. I built new features on the new architecture and fixed faults on the old one at the same time, with both running side by side. Customers saw a site that kept working and gradually got better, not a big risky relaunch.

Making releases boring

Getting a change live was automated from start to finish, with checks that run on every change to catch mistakes before customers ever see them. The goal was to make releasing dull — the point at which a team stops planning releases and simply ships.

Working with the wider team

I worked alongside designers and testers rather than taking finished designs and handing back finished code, which caught the awkward details early — the states nobody thought about, the things that break on a small screen.

Where it landed

• Teams release around three times as often as before.
• No team is blocked by another team's unfinished or broken work.
• The site measurably improved on the speed checks Google uses to rank pages.
• Shared parts are built once and reused, instead of rebuilt per team.