Case study - AI engineering

Generating 14,000+ exam-grade questions, and ensuring they are right

Examworthy is a certification study platform built solo. The hard part was never the app - it was a reliable LLM generation pipeline and a multi-vendor evaluation layer that does not rely on any single model.

  • Built solo
  • 2026
  • Perth, WA
Examworthy homepage with a live sample certification question
Examworthy per-domain readiness panel showing which domains clear the pass line
Examworthy on mobile
certifications
58*certifications
audited questions
14000+audited questions
spaced-repetition flashcards
36000+spaced-repetition flashcards

* At the time of writing - the catalogue grows weekly.

The problem

The hard part is correct content at volume.

Certification candidates choose between cheap question dumps that are often wrong or stolen, and expensive official courseware. The hard problem behind a good product is not the interface.

It is producing thousands of original, technically-correct, exam-representative questions across dozens of certifications - cheaply enough that the unit cost does not sink the business. That is an AI engineering problem, not a content-writing one.

The pipeline

Defence in depth for content.

Every question moves through a deliberate state machine. Nothing reaches the product on a single model's say-so.

1 - Generate
Each run is pinned to one certification, domain, and exam objective from the public blueprint. Provenance fields are overwritten after generation, so the model physically cannot drift them.
2 - Eight deterministic gates
Structural checks, content-quality classifiers, and cross-field consistency checks - spanning schema integrity, distractor quality, bias detection, and citation integrity. A failure is a hard reject.
3 - Three-judge eval panel
Each survivor is scored on five rubric dimensions by three independent LLM judges. Correctness and fabricated-reference are veto dimensions - one failing vote kills the item regardless of the majority.
4 - Human review
A person is the last gate. Eval-passed questions are read by hand and explicitly approved, edited, or cut - nothing reaches the scored pool without that sign-off, and any edit is sent back through every gate before it can return.
Generation pipeline dashboard showing three AWS certifications generating in parallel, each with a progress panel and a column of live activity logs.
The standard pipeline generating three AWS certifications in parallel - per-certification progress against target, with a live activity log under each.
The interesting part

An eval that does not trust one vendor.

A cheaper hybrid pipeline was benchmarked blind against the production bank, provenance stripped, scored by judges from two different model families. It reached production grade. It did not ship, because the one material gap was citation quality.

Why two families
An author and a judge from the same vendor share a blind spot, so the judge waves through the mistakes the author is prone to. Agreement between families is the only number worth defending, and here it was 91%.
The decision
A cheaper pipeline reaching production grade does not justify swapping a known-good bank for one with weaker citations. Keep the bank, stay on the model that is ahead, retest when the next capable lower-cost model lands.
The method, in full
The scoring tables, the four-model author comparison down to a local 14B, and what generalises beyond exam questions are written up separately as research.

Read the benchmark

The product

A real study app behind the pipeline.

Spaced repetition
A from-scratch SM-2 scheduler, implemented as a pure function with no hidden clock - fully deterministic and unit-testable, with Anki-style four-button grading.
Readiness, per domain
A dashboard that derives mastery from practice history and predicts exam score against the pass line, with drill-down into the weak concepts costing the most marks.
Built for production
Custom auth, Stripe billing, self-hosted Postgres behind PgBouncer, strict security headers, and a CI gate that fails the build on banned characters or hardcoded colours.
What it proves

Not prompting. Engineering.

0-to-1, solo
A complete, deployed, billable SaaS - frontend, backend, auth, payments, content, infrastructure - built by one engineer in weeks, with the catalogue still growing 1-2 certifications per week off the same pipeline.
A real LLM system
Deterministic gates, a multi-judge eval panel, schema enforcement, and a measured approach to model selection, cost, and bias - not a single prompt behind a button.
Judgement under tradeoffs
Frontier-versus-local and cost-versus-quality decisions backed by evals, not opinions - including the discipline to not ship a change that was only churn.
Stack
  • TypeScript
  • Next.js 15
  • React 19
  • PostgreSQL + PgBouncer
  • Custom auth + OAuth
  • Stripe
  • Claude Opus + Sonnet
  • GLM 5.2
  • Qwen (local)
  • Vitest
  • Playwright

Have something to build?

Tell us what you are working on. We reply within a day, in plain language, with a clear next step.

Prefer email? hello@solaisoft.com

Perth, Western Australia