Guides & explainers
Longer reads to go with the drills — worked examples and plain-English explanations, each checked against primary sources and linked to a question bank you can practise on. New guides are published most days.
AWS SAA-C03
- How the SAA-C03 exam is scored and formatted
- RDS Multi-AZ vs read replicas vs Aurora Global Database, with AWS's own RPO/RTO numbers
- IAM Identity Center vs SAML federation vs Cognito identity pools, compared
- Lambda concurrency worked example: reserved vs provisioned vs unreserved, one traffic burst traced
- AWS disaster recovery strategies: RTO/RPO worked example
- S3 storage classes compared: cost, retrieval time & minimum duration
Accounting: GAAP & IFRS
- Deferred commissions under ASC 606 (ASC 340-40), explained
- IAS 37: expected value vs most likely outcome, worked examples
- Forward repurchase contracts for own shares under ASC 480 (worked example)
- Nonrefundable upfront fees (ASC 606-10-55-51): defer, and for how long
- The "simultaneously receives and consumes" test (ASC 606-10-25-27)
- The residual approach to standalone selling price (ASC 606-10-32-34)
- Contract modifications (ASC 606-10-25-12/25-13): the three outcomes
- ASC 360-10-35-44: held-for-sale reclassification, with journal entries
- The ASC & IFRS standards citation index (84 standards, every one we cite)
Tax: UK/US/UAE/KSA/EU
- EIS vs SEIS vs VCT tax relief compared (2026/27)
- UK dividend tax rate rise 2026/27, with worked examples
- OSS vs IOSS vs standard VAT registration, compared
- VAT Margin Scheme vs Global Accounting, worked example
- QSBS's new OBBBA exclusion tiers, worked example
- Saudi WHT rate schedule
- Effective vs marginal tax rate, with 2026 brackets
AI & LLM Engineering
- Which agent workflow pattern to use: Anthropic's 5 patterns compared
- Reciprocal Rank Fusion (RRF), with a full worked example
- Cohen's kappa vs Fleiss' kappa, worked by hand
- GRPO vs PPO: a worked example comparing the advantage calculation
- Temperature vs top-p vs top-k: how they combine (worked example)
- Which prompting technique to use: CoT vs self-consistency vs ReAct vs ToT
Trivia
- Convergent vs divergent vs transform plate boundaries, explained
- Where everyday words like OK, robot and canary actually come from
- Why isn't Pluto a planet? The numbers, explained
- Blood type compatibility chart: who can donate to whom, explained
- Why flags share colors: pan-African, pan-Arab & pan-Slavic explained
School
- Lay vs. lie: the test, the chart, and 10 worked practice sentences
- The 12-coin weighing puzzle, solved step by step (all 3 weighings)
- Where sports words and famous "facts" actually come from
- Binary, ASCII & RGB explained: how a byte becomes a letter or a color
- The il-/im-/ir- prefix rule, explained (with word lists)
- Mental math tricks explained: the algebra behind the shortcuts
Stock Market & Investing
- Yield to call vs yield to maturity, worked example
- Bond duration & convexity, a full worked example
- Behavioral finance bias pairs investors mix up, side by side
- Sharpe, Treynor, Sortino, Jensen's alpha & information ratio compared
- Two-asset portfolio variance & minimum-variance weights, worked example
- DCF terminal value: perpetuity growth vs. exit multiple, worked example