CertBrain is our new study site for the AWS Certified AI Practitioner (AIF-C01) exam, at certbrain.app. It starts with a free diagnostic quiz that shows which exam domains you’re strong in and which need work, then teaches each domain through short lessons, practice questions and flashcards on a spaced-repetition schedule.
It’s the third product on the platform behind Braineos and Finance Brain. We’ve written about how one codebase runs several products. This post covers what was different this time: content that has to be right, a paywall that doesn’t exist yet, and a quiz that remembers nothing.
A third site, almost no new app
Launching CertBrain was mostly configuration: a new site profile with its name, brand and copy, the features it needs switched on, and everything else switched off. It has its own database and sign-in, kept separate from the other products.
The new code was small and specific to exam prep: a way to lock content, and a diagnostic quiz anyone can take without an account. Both work on every site on the platform, so the next product that needs them gets them for free.
Locked content stays visible
Elsewhere on the platform, a switched-off feature disappears completely, as if it was never built. CertBrain’s premium content is deliberately different. Every course, lesson title and description stays visible to everyone, and only the lesson itself and its practice are locked. People need to see what they’d be getting.
Each domain has a free sample, so nobody is locked out of a whole topic. The rest is built and in place, but nobody can open it yet: payments come later. The gate is a single check: is this lesson marked premium, and if so, does this person have premium? Nobody has premium until billing exists, so the paywall behaves correctly from the first day, and there’s nothing to flip by hand when it goes live. Content is unlocked unless marked, so the other sites, which have no premium content, aren’t affected at all.
A diagnostic that stores nothing
The diagnostic needs no sign-in, so we decided it shouldn’t store anything either. Your browser gets a fixed set of questions across all five exam domains, scores your answers itself, and shows your results straight away. Nothing about your attempt is saved to our database. The only record is an anonymous analytics event with the per-domain scores, so we can see whether people find the quiz useful.
We considered saving results so we could email them to you later. That’s real infrastructure, and a real privacy question, for a feature nobody had asked for yet, so we left it out.
The content is the product
In exam prep, trust is the whole product. Question banks of unclear origin are common, and a wrong answer key costs people marks on the real exam. So we set three rules:
- Original content only. Everything is written from AWS’s public exam guide and documentation. Nothing is copied from another course, and nothing comes from the real exam.
- Every item has a source. Each lesson, question and flashcard records its exam domain, its task statement, its difficulty and the AWS documentation page that backs it up.
- Retired services are never the answer. AWS has closed several AI services to new customers and retired some models. They can still come up in study material, so lessons mention them with a note that they’ve closed, and no question uses one as the correct answer.
The course has 70 lessons, 300 practice questions weighted to match the exam’s domain percentages, and a set of flashcards. Every item was reviewed against its cited source, with a sceptical second pass after the fixes. Most problems the review caught weren’t wrong answers. They were sources that didn’t actually say what the question claimed. We fix those before an item goes live.
What the launch taught us
The third launch was the first one done from a written checklist, and it showed where the checklist was still vague. Two settings in the web server configuration had to be corrected against a site that was already working, because the checklist described them in words rather than giving a file to copy. We’ve noted that and a few other fixes, so the fourth site starts from tested templates instead of descriptions.
Try it
Take the free CertBrain diagnostic to see where you stand across all five exam domains, then start with the free sample in each one.
CertBrain is an independent study resource. It isn’t affiliated with or endorsed by Amazon Web Services. AWS and AWS Certified AI Practitioner are trademarks of Amazon.com, Inc. or its affiliates.