Jonathan Gu

Machine learning at Coframe

Work

Coframe uses AI to improve and personalize online stores. My part is the machine learning that decides what each shopper sees: which products appear beside the one they are looking at, the order of a category page, what search returns and what to suggest to someone hesitating over a cart.

Recommendation rails

Hand-inked drawing of a toy train whose cars carry products in ranked order, wired to a signal box marked MODEL

Every store has a row that says “You may also like.” Ours form a view of the shopper on the first visit and revise it after the next product they look at. A substitute and a complement are different questions, so each gets its own model, and what a shopper has already viewed is something the model weighs rather than a rule it obeys.

Search results reordered by what the shopper meant rather than the exact words typed, learned from how people search and what they then buy.

Feeds & grids

Hand-inked drawing of a three by three cubby shelf of product cards beside a taste meter

Collection pages and homepages, put in a different order for each visitor. One product view is enough for the grid to reconsider.

The ML factory

Hand-inked drawing of a little factory line: a glass tube of shopper events, a hopper, a grinder, an oven and a press that stamps the model

Events, features, training, evaluation, publishing and serving, in one place. A model learns the goal of the experiment it serves, which is usually revenue per visit. A client’s request becomes a working model within hours, and the model retrains every day.

Head to head

Hand-inked drawing of two little shops, A for the old way and B for the new model, with a splitter sending shoppers to each and scoreboards on the roofs

Every model goes live as an experiment against whatever was on the page before, including established vendors in their own slots. A new model replaces the old one only when it is at least as good, and a gain that sits inside the noise does not count. It must also beat the best simple rule, which is more humbling than you might expect.

The experiment engine

Hand-inked figure: the experiment engine, where every finished test feeds the next ideas

Every test, won or lost, teaches an engine that proposes the next ideas for every client. Agents build the ideas, and people decide which of them deserve a store’s visitors.

The switchboard

Hand-inked drawing of a switchboard: use-case cards slot into a registry, a shadow lamp, a gate light and a flip lever wire a storefront to the new platform

Each client’s request becomes a record that says what to show, what to learn from and how success will be judged, with custom code only where the record cannot say it. A short check proves that the data exists before any training is paid for. Clients are walled off from one another. A new model answers quietly beside the old one before anyone sees it, and the way back is written down before the switch.

The command center

Hand-inked drawing of a control room: a plan board of ordered work, lanes, robot builders at benches, an advisor, a two-lens checker, a merge gate and a locked live storefront

I build all of this with a company of AI agents. One plans the work, another audits the plan, and builders take the rows. A grader from a different family of models checks what they produce, on the reasonable theory that nobody should mark their own homework. A piece of work is finished when a script prints PASS, not when an agent says so, and the person who owns a launch decides when it launches.

Side A

Everest in the late afternoon sun, the first picture of the Side A film
  1. 1Bus Stop Confetti4:11
  2. 2Three Hearts Inside a Stolen Ship5:05
  3. 3One More Thing4:38

Family

Jonathan with his wife and their two kids on vacation, all four smiling
The four of us, briefly facing the same direction.
Everest and Maggie riding together in a green grocery cart in front of a wall of fruit
Saturday groceries, with two passengers who do not help.
Everest in a tie-dye shirt, standing in the late afternoon sun
Everest, in the last of the afternoon sun.
Maggie with two little pigtails, sitting by a bright window with flowers behind her
Maggie by the window, considering her options.
Jonathan’s son and daughter laughing together at the kitchen table
A birthday, which her brother has taken charge of.
Jonathan on a shaded walkway with Maggie in a baby carrier, Tina and Everest on a bench behind them
Out for a walk, all four of us.
Everest at the table, gluing green paper triangles onto pink paper
Everest, applying glue with great seriousness.
Maggie grinning on the rug in a green-trimmed bib
Maggie, who finds most things funny.
Everest outside in a blue fleece, holding a long branch in one hand and a toy truck in the other
He found the best stick, and brought a truck in case.
Maggie sitting on the rug in a knitted sweater, holding a blue stacking ring
Rings, in order, eventually.

“I do it”

The best sound in parenting is “help me” turning into “I do it.” A balance bike gets there faster than any lecture.

Little boat, fat boat

On the walk home along the water, every boat must be assigned a role in the family. The little boat is Maggie. The fat boat, I am told, is Daddy.

Anything with wheels

Monster trucks, fire trucks, trains and cranes are all examined from as close as an adult will allow, and for as long as one will wait.

Five books at bedtime

Five books, every night, because five is currently the largest reasonable number in the universe. So far, the books are winning.

Two languages

Our home runs in Mandarin and English. The songs we sang to our kids, they now sing back to us.

Saturday pancakes

He mixes the batter with great seriousness. His little sister supervises and handles the cheese.