Wiring Adobe Target into an AEM front end through the Web SDK (commonly referred to by its library name, Alloy) replaces the older at.js implementation model, and several of the pitfalls teams hit come directly from treating it like a drop-in at.js replacement rather than a different integration pattern.
Flicker and personalization timing
The most visible pitfall is content flicker: the default page renders, then personalized content swaps in a moment later. Web SDK's approach to preventing this differs from at.js's traditional pre-hiding body technique. Teams that copy the old at.js flicker-prevention snippet verbatim often end up with either a broken hide/show flow or a body that stays hidden too long, hurting perceived performance.
Datastream configuration mismatches
Web SDK routes through an Experience Platform datastream, which needs to be correctly configured to route to the right Target property and Analytics report suite. A datastream misconfiguration does not usually throw an obvious error — activities simply do not fire, which looks like a Target authoring problem rather than a plumbing problem.
Server-side vs client-side rendering decisions
Where personalization decisions are evaluated (client-side in the browser vs. server-side before the page renders) has real implications for both flicker and for how well the personalized variant can be indexed or cached. Decide this deliberately based on the page type rather than defaulting to whatever the initial proof of concept used.
Common pitfalls checklist
- Copying at.js flicker-prevention patterns instead of using the Web SDK-native approach
- Not validating the datastream's Target and Analytics mappings before assuming activities are broken
- Loading the Web SDK library synchronously in a way that blocks page render more than the personalization value justifies
- Testing only in a single browser/session state, missing edge cases with ad blockers or strict cookie policies that affect identity resolution
Most Web SDK/Target issues in AEM implementations are integration and configuration issues rather than platform bugs — budget real time for datastream and flicker-handling validation rather than treating the SDK swap as a one-line script change.