ProSiebenSat.1

The brief

Be the central service provider for the group's HbbTV applications — and do it in a way that does not multiply by seven every time a channel asks for something.

The constraint

Seven distinct channel brands, each with its own look, its own editorial team and its own schedule, sharing one platform and one release train. The failure mode here is the opposite of a multi-runtime project: not five codebases drifting apart, but one codebase slowly acquiring seven exceptions.

What follows is what we built on it. None of it is the problem it would be in a browser.

Three surfaces, seven times, without seven forks

Every brand gets the same three surfaces, and each is a different problem from its web equivalent.

The Mediathek

A web catalogue leans on a search box and a mouse. An HbbTV catalogue has neither, so the browse structure is not a fallback for search — it is the product. Underneath sits memory: thirty posters are thirty decoded bitmaps, and a television from 2016 will not hold them. Scroll position, focus model and image lifecycle become one mechanism rather than three, or the set stutters exactly when the viewer moves fastest.

Themed channels

A playlist that has to behave like transmission. Viewers have thirty years of expectations about what a channel does, and a visible gap between two items breaks every one of them — so the next item is prepared while the current one still plays, inside a memory budget that will not hold two comfortable decoders.

EPG

A two-dimensional grid navigated with a four-way pad: solved on a desktop, unsolved on a remote, because the viewer's model is “later” and “another channel”, not “right” and “down”. A week of data is more than a terminal will hold, so the grid is windowed around where the viewer is looking, and now-and-next stays correct by reasoning about time rather than asking the backend.

None of that is the interesting part of this project. The interesting part is that it exists once and seven brands use it.

Every entry arrives in the same ninety seconds

A competition attached to a live format has a traffic profile unlike anything on the web: nothing, nothing, nothing, then the host says the sentence and every entry arrives at once. The engineering is not the form; it is a spike whose timing is known in advance and whose magnitude is not.

On the client, the constraint is text entry — typing an email address with a remote is genuinely unpleasant, so every field that can go, goes. And there is a legal surface most web forms do not have: participation terms, age checks and data protection, on a device the whole household shares.

SwitchIn — an ad format that must not damage the ad

SwitchIn is addressable TV advertising, and the format that makes an HbbTV application pay for itself. During a commercial, an animated element appears over the broadcast picture and invites the viewer to press a key and enter the advertiser's application — delivered per receiver over broadband, which is what allows it to be addressed at all.

The whole difficulty is in the word “over”. The spot is still running underneath, it was paid for at broadcast rates, and nothing may cover it, delay it or stutter it. The overlay has to be signalled, loaded and animating inside the break, and it has to animate smoothly on a GPU that is a decade behind the phone in the viewer's hand.

Beneath that sits the part advertisers actually buy: impressions and interactions counted in a way that survives an audit, because this is inventory that is sold.

Landing pages that ship to a broadcast schedule

Campaign screens for a running show — The Voice of Germany, Germany's Next Topmodel — are the one kind of television application with a deadline nobody can move. The air date is the air date. Content changes with each episode, and the traffic arrives in the minutes after an on-air mention.

That turns a design question into an operational one: the editorial team has to be able to change the screen between episodes without a release, which is the whole argument for a headless CMS sitting behind the app rather than a build pipeline.

One platform, seven brands

A Drupal headless content management framework with React frontends for ProSieben, Sat.1, Kabel Eins, Puls 4 and ATV, among others. VAST advertising inside the HbbTV player. Automated daily ingest of formats and clips from the pre-production systems, so nobody retypes a schedule. And an editorial playlist builder, so the schedule is made by the people who know the schedule.

The brand differences live in configuration and design tokens, not in forks. That is the only reason seven brands can share one release train.