This Week I Learned - Week 21 2026

This Week I Learned - 

* web.py was originally published while Aaron Swartz worked at reddit.com, where the site used it as it grew to become one of the top 1000 sites according to Alexa and served millions of daily page views. Reddit was rewritten using other tools after being acquired by Condé Nast in 2006.

* Markdown is used widely by websites including Reddit, GitHub and Discord using it, as well as LLMs such as Claude using it to format the files that store accumulated memories.

* Anthropic, OpenAI, and Google all raised effective prices in the last six months. Enterprises that built workflows assuming AI costs would keep falling are now watching annual budgets evaporate in months. 

* Uber's CTO sent an internal memo warning the company burned through its entire 2026 AI budget in just four months. American AI software prices have jumped 20% to 37%, and GitHub (owned by Microsoft) is dropping flat-rate plans for usage-based billing across its products. - Hedgie

* Model family prices change rapidly. Old models get deprecated. Best to be prepared.

1. Add multi-tier routing to your architecture
2. Compare completed-task costs, not token price. A 2* more expensive model can halve the retry rate, making it cheaper per successful output.
3. Migrate by model capability, not model family. Switch to models with similar latency, context window, output format compliance and reasoning depth.
4. Evaluate open-source models. DeepSeek models at self-hosted inference costs can be 90% cheaper for commodity (not frontier) tasks.

The first 18 months of most AI model families are discounted customer acquisition. Then value extraction follows. 

Just keep asking yourself: “what’s our plan for when this model changes or deprecates?”

* Promptfoo is an open-source command-line tool designed for test-driven prompt engineering and LLM (Large Language Model) evaluation. It allows users to test multiple prompts against predefined test cases, evaluate outputs side-by-side, and integrate with test frameworks.

* Sycophantic AI Decreases Prosocial Intentions and Promotes Dependence - The AI is not just telling you what you want to hear. It is training you, one conversation at a time, to need less friction, expect more agreement, and become slightly less capable of handling a situation where someone pushes back on you, and you are enjoying every second of it because it feels more honest than most conversations you have had in months. Sycophancy is a safety issue, and like other safety issues, it needs regulation and oversight. 

* Infrastructure is invisible as long as it works. In 2025, running the Open Food Facts infrastructure cost around €169,660 for servers, subscriptions, a full-time engineer, and volunteers who contribute dozens of days a year.

* Google used to offer a static Image Charts API where you could generate charts with a simple URL. This service was shut down in 2019 (deprecated since 2012). If you want the simplest "pass parameters via URL → get chart image" experience, switch to QuickChart (free tier available, open-source self-host option too). It's the most popular replacement for the old Google Image Charts. These images are suitable for embedding in email, SMS, chatbots, and other formats. Charts are rendered by Chart.js, a popular open-source charting library.

* QuickChart was founded by Ian Webster in 2015

* Sivaramakrishnan "Soma" Somasegar joined Microsoft in 1989 and spent his first decade at Microsoft on the NT team, ultimately contributing to eight releases of the Windows operating system. He founded Microsoft’s India Development Center in Hyderabad in 1998. In 2014, Somasegar was an internal advocate and leader for Microsoft’s decision to open-source the .NET core server runtime and framework, a surprise move that marked a significant shift in the company’s approach toward the broader developer world.

* Ultrasound’s very short wavelength allows it to travel through biological tissues. It is also propagated as a mechanical wave, where one molecule pushes against the next, and therefore it travels at a faster speed in stiff and incompressible tissues such as bone, but is slower in tissues such as fat. This property is used to generate ultrasound ‘images’ of human foetuses. 

* In a stark shift, the India’s stock market is on the verge of dropping out of the world’s five biggest for the first time in three years. Its market value soared from pandemic lows to a record $5.73 trillion in September 2024, with the NSE Nifty 50 Index the world’s best-performing major market at the time. Since the peak, $924 billion of market value has evaporated. Foreign investors are rushing to the exit — they have withdrawn a net $42 billion since the end of 2024...foreign investors ... now hold less than domestic institutions for the first time in more than 20 years. The stock market is heavily weighted toward IT services, a $315 billion industry led by Infosys and Tata Consultancy Services. The IT industry’s Nifty weight has fallen to about 8% from more than 17% in early 2022. As many as 15 million Indians work in IT services and global capability centers, many in some of the country’s best-paying private jobs. A structural slowdown in hiring or a more fundamental shift in global demand for the services would ripple across the economy, into real estate, consumption, lending and the broader financial sector. Gross domestic product will likely expand 6.5% in 2027 and 2028 each after an average annual rate of 8.3% in the last four years, the International Monetary Fund predicts. - Japan Times