Background knowledge and practical explanations for the topics our tools cover — from cryptography to travel and visa rules, web standards, and security.
More and more invoices, donation flyers and club letters now carry a small QR code labeled "GiroCode". Scan it with your banking app and you no longer have to type in the IBAN, amount and payment reference by hand: the…
Read more →Today, 17 June 2026, the Federal Statistical Office confirmed the final inflation figures for May 2026: consumer price index (CPI) at +2.6 % year-on-year, harmonised consumer price index (HICP) at +2.7 %. Core inflation…
Read more →Since early 2026 Chrome 111+, Edge 111+, Firefox 113+ and Safari 15.4+ all support oklch(), oklab() and color-mix() — covering over 95 % of browsers worldwide. What was an experimental feature behind browser flags two…
Read more →A heat pump in Germany in 2026 costs on average EUR 27,000–32,000 including installation. Sounds like a lot — and it is. But: the BEG (Federal Subsidy for Efficient Buildings) pays back up to 70 % of that. Anyone…
Read more →2026 is the year passkeys jumped from 'cool but who actually uses them?' to 'why do you still have passwords?' The FIDO Alliance reports over 1 billion activated passkeys in June 2026, 48 % of top-100 sites support the…
Read more →In May 2026 a team at the University of Szczecin published a meta-analysis of 32 sleep studies covering 1980 to 2026. The headline finding is subtle but important: even when you fall asleep after the afternoon espresso…
Read more →Since 10 April 2026 the new Entry/Exit System (EES) has been live at every Schengen external border. In Q4 2026, ETIAS arrives — an online pre-authorisation for visa-exempt travellers. What is genuinely relevant if you…
Read more →On Thursday, 11 June 2026, the European Central Bank raised its key rates for the first time in more than a year — all three by 25 basis points. The deposit rate is now at 2.25 %, the main refinancing rate at 2.40 %…
Read more →On 19 January 2038, at 03:14:07 UTC, the signed 32-bit Unix timestamp overflows. That sounds like tomorrow's problem, but in 2026 it is already today's: contracts with 30-year terms, database schemas being frozen now…
Read more →Everyone recognizes the black-and-white square: on the restaurant menu, on a parcel label, on the EPC payment in online banking, on a train ticket. What hardly anyone knows: the QR code was not invented for consumers…
Read more →Lorem ipsum dolor sit amet, consectetur adipiscing elit is probably the most-read and least-understood sentence in the design world. It looks like Latin but doesn't quite make sense. It has been preinstalled in every…
Read more →Markdown is probably the most productive language youll ever learn -- a few dozen rules, useful for the rest of your career. README files on GitHub, issues on GitLab, messages on Discord, docs in MkDocs, blog posts in…
Read more →Three letters, three worlds: JSON, YAML, and TOML all solve the same problem -- structured data in plain text -- but they do it in fundamentally different ways. Pick the wrong one for your project and you pay with bugs…
Read more →A URL is more than a technical address — it's a tiny piece of brand communication, an SEO signal, a trust lever in a shared tweet, and a page's first impression in Google's search results. Even so, the 'slug' — the…
Read more →19 percent in Germany, 20 percent in France, 27 percent in Hungary, 8.1 percent in Switzerland — and in Luxembourg there is a rate of exactly 3 percent for certain books. Anyone who invoices across Europe, runs an…
Read more →Few topics are as awkward in everyday travel as tipping. Tip 10 percent in New York and you'll get cold looks; tip 10 percent in Tokyo and you insult the server. In Paris tipping is optional, in Berlin expected, in…
Read more →The Bausparvertrag is one of the most German financial products of all: 28 million contracts are active in Germany, the market share of Schwaebisch Hall, BHW and LBS has been stable for decades, and an ad brochure hangs…
Read more →When the evening news reports that inflation stands at 2.4 percent, and at the same time you feel your weekly shop is now a third more expensive than two years ago — that isn't perception bias. It's because the official…
Read more →Lookarounds are the feature that turn regular expressions from a toy into a professional tool. They let you write conditions like "check whether a word follows without consuming it" or "find a comma that isn't wrapped…
Read more →Three calorie calculators, three results, all different — and none of them tells you why. Behind it sits the math of BMR (basal metabolic rate), PAL (activity factor), and TDEE (total daily energy expenditure), plus…
Read more →When creating a new table, most developers reflexively reach for UUIDv4 as the primary key — it's available everywhere, unique, and simple. But v4 has a stubborn performance problem in large tables that UUIDv7 (RFC…
Read more →Buying a house or apartment in Germany costs more than the headline price: real estate transfer tax (Grunderwerbsteuer) sits on top, and it varies a lot by state. On a 500,000 EUR property, depending on the state…
Read more →60,000 USD a year sounds decent. 40 hours a week times 4.33 weeks a month — quick math, that's around 30 USD per hour gross. But if you count honestly — commute, unpaid overtime, ironing shirts, decompressing on the…
Read more →Designers love elegant light grey on white. Users with low vision, older people, or anyone reading their phone in summer sunshine hate it. The Web Content Accessibility Guidelines (WCAG) have provided concrete numbers…
Read more →You have an espresso at 3 pm, feel fine in the evening, and then wonder why you're staring at the ceiling at 2 am. Pharmacokinetics are to blame: caffeine has a surprisingly long half-life, and most people underestimate…
Read more →Albert Einstein allegedly called compound interest the eighth wonder of the world — the quote is unverified, but the math behind it is not. Whoever starts saving early gets a head start that even double the monthly…
Read more →Passwords are like shoes: at some point you have too many, they often pinch, and once in a while you lose one. But unlike shoes, passwords protect access to our digital existence — email, banking, taxes, photos. How…
Read more →Cron expressions are a strange mix of brilliant and cryptic. Five fields with digits and special characters are enough to describe arbitrarily complex schedules — from a daily backup at 03:15 to "every other Tuesday of…
Read more →JSON Web Tokens are everywhere in modern web APIs: single sign-on, OAuth flows, OpenID Connect, serverless authentication — almost everything touches this compact token format. Behind the cryptic-looking string made of…
Read more →The Schengen 90/180 rule sounds simple at first: stay in for 90 days, then out. In practice, the bookkeeping is trickier, because the 180-day window isn't fixed but rolls forward each day. Anyone traveling visa-free…
Read more →The Body Mass Index is one of the best-known fitness metrics. A single number derived from height and weight — quick to compute, easy to compare. But it has blind spots. Anyone who lifts regularly has probably noticed…
Read more →Hash algorithms are the quiet workhorse behind file integrity, password storage, digital signatures, and blockchains. But not all hash functions are equally secure: MD5, ubiquitous for decades, is now considered broken…
Read more →Since January 2026 Germany's flat-rate transit pass, the Deutschlandticket, costs 63 euros per month — and from 2027 onwards its price will track an index of labour and energy costs, which all but guarantees further…
Read more →