I prefer a barbell strategy: spend about 90% of your effort on the project that has already shown signs of working, and use the other 10% to run cheap tests on new ideas.

But what counts as “cheap”? A test can cost almost nothing in cash and still waste weeks of your time. It helps to put numbers on it.

Start with two rough numbers

First, estimate the value of the project. Say you think it has a 5% chance of producing $100,000:

That is a rough estimate, not a valuation. Its purpose is to give you something to update as you learn.

Second, value what you would give up. If you work on a side project outside business hours, your salary is not the right benchmark. You cannot necessarily exchange those evening or weekend hours for more salary.

The real alternative might be training that advances your career, meeting people in your industry, improving a micro-SaaS that already makes $5,000 a month, or simply exercising, resting and spending time with people you care about.

Most of those do not have a neat dollar price. One workaround is to set a personal reservation rate: the minimum value an hour on a new project must offer before you are willing to give up that time. If you set it at $50, a ten-hour experiment costs you $500 of scarce free time.

The estimate will be imperfect. That is fine. Treating your free time as worthless is much less accurate.

Price the next test

Suppose a test takes ten hours and costs another $500 for ads, data or a prototype. At a personal reservation rate of $50 an hour, its real cost is:

Now suppose fully pursuing the project would require another $5,000, and a successful outcome would be worth $100,000.

Before the test, you believe the chance of success is 5%. The project’s expected gross value is therefore $5,000, exactly equal to the cost of pursuing it. There is no margin of safety.

The test could change the decision. You estimate an 80% chance of a weak result, which would reduce the probability of success to about 1%. You would stop. There is also a 20% chance of a strong result, which would raise it to 20%. In that case:

After subtracting the $5,000 needed to pursue the project, the strong result is worth $15,000. Because you expect that result 20% of the time:

Finally, subtract the $1,000 cost of the test:

The test does not magically create $2,000 in profit. Its value comes from the decision it enables: abandon the idea when the evidence is weak, and make the larger bet only when the evidence improves.

The 2/20/200 rule

This is Rob Walling’s 2/20/200 validation framework, which he explains in episode 706 of Startups for the Rest of Us. It follows a simple progression:

• 2 hours: Research the problem, market, competitors and existing demand online.
• 20 hours: Interview potential customers and test a landing page through outreach or ads.
• 200 hours: Build the smallest usable MVP and see whether people use it or pay.

At each stage, ask whether the next step is worth the information it can give you. A cheap test has a capped downside and a decision attached to it. If the result will not change what you do next, the information is not worth paying for.

One of the friction points with running a Jekyll blog is that publishing requires access to your development machine. You need to create a markdown file, add the right front matter, commit, and push. It’s not something you can easily do from your phone while waiting for coffee.

Today I solved that problem using Clawdbot, an open-source AI assistant that connects to messaging platforms like Signal, Telegram, and WhatsApp.

The Setup

The workflow is simple:

1. Send a Signal message to my Clawdbot instance with the post idea
2. Clawdbot formats it as a proper Jekyll post with front matter
3. Clawdbot commits and pushes to GitHub

The assistant has access to my blog’s repository structure, so it knows the correct format for posts, the categories I typically use, and the front matter fields I need.

Why This Works

Static sites are great for many reasons—speed, security, simplicity—but they traditionally sacrifice the convenience of mobile publishing that platforms like Substack or Medium offer. This setup brings back that convenience without giving up control over my content.

The AI handles the tedious parts:

• Generating the filename in YYYY-MM-DD-title.md format
• Adding consistent front matter
• Formatting the markdown properly
• Committing and pushing to GitHub

I just focus on the ideas.

The Technical Details

Clawdbot runs as a local gateway on my Mac, connecting to Signal via signal-cli. When I message it, the request goes to Claude (Anthropic’s AI), which has access to tools that can read and write files in a sandboxed workspace.

To give it context about my blog, I cloned my repository into its workspace. Now it can see my existing posts and match the style and structure—and push changes directly.

Trying It Yourself

If you run a Jekyll blog and want to experiment with this workflow:

1. Install Clawdbot and connect it to your messaging platform of choice
2. Clone your blog repo into the assistant’s workspace
3. Start sending post ideas

The barrier between “having a thought” and “publishing it” just got a lot smaller.

This post was drafted via Signal message and published by Clawdbot.

Thank you for spending time with this small newsletter over the past year. It began as a simple internet experiment; I shared links to things I was reading and thinking about, mostly to impose some structure on my own curiosity. Somewhere along the way, it found a small audience.

There are now just under 250 of you here, with roughly half opening an email in a typical week, assuming I manage to send one. Even more surprising, five people decided it was worth paying to read summaries of things I find interesting. That remains genuinely unexpected, and I am grateful to those of you who chose to support it.

Writing a newsletter, even a modest one, takes more time than it appears, automation notwithstanding. While I have technically published something every week, punctuality has been inconsistent, particularly towards the end of the year. More importantly, I no longer find it especially rewarding to produce regular summaries of concepts and articles.

On top of that, my focus is shifting more decisively towards building. While I do enjoy both creative processes, I definitely get more out of creating things than writing about, well, stuff. I find these words by the Roman philosopher Seneca worth reflecting on:

“It is not that we have a short time to live, but that we waste a lot of it. Life is long enough, and a sufficiently generous amount has been given to us for the highest achievements, if it were all well invested.”

In that spirit, I’m focusing more of my spare time on what I want to do more of: building software projects, distributing them, and learning more about the process.

Rather than ending this project though, I am changing the format. The overhead will be reduced. This will become a place to quickly share things I find interesting, with occasional longer, data-led pieces when I have something substantial to say and the time to say it properly, without a set schedule. The output style of the Marginal Revolution blog of “write it quickly and publish” is a good frame of reference for how this blog will function from now on.

Substack will also act as a mirror of my blog and as the subscription and email layer. All of Interessant3 now lives on both platforms. If you are curious about the mechanics, the backend system is all documented here.

I’ve also started working on another two projects which may be of interest to this audience:

1. ‘EuropeVersus’ - name still subject to change - an open source repository of socioeconomic data with a focus on Europe. Data is collected from reputable sources and this website provides handy logic so users can compare how different subsets of Europe compare versus India, the USA, and China. Ever wanted to know how the Eurozone’s productivity compares vs the USA, or the life expectancy of the EEA vs China? This is the place to do it easily with beautiful visualisations. I will also be publishing data-led articles here on common discussion points regarding europe, such as on its productivity, crime rates, democratic standing, etc. You can find and contribute to the repo here, and check out the staging site here.
2. VoxPopli - this is aimed at being an alternative to Twitter and Slack groups specifically for builers. Think of a social media platform with no rage-bait promoting algorithm, a downvote button, a free and working API, and a tonne of tools to help builders. You can check it out here.

I hope 2026 brings you many interesting things to discover!

Duarte

• The political implications are stark: if current projections hold, immigration may cease to be the wedge issue it once was.
• Link: Are We Heading for Net-Zero Immigration? – UnHerd

1. Pay Transparency Laws – Simon Quach et al.
   • When Colorado and other US states required salary disclosure in job listings, the results defied expectations and led to a 2% overall salary increase.
   • Pay rose across the board, especially for lower earners, without affecting employment rates or skill demands.
   • Transparency intensified competition among employers and improved workers’ bargaining power. Labour market efficiency improved as information asymmetry between employers and applicants shrank.
   • The findings suggest simple policy nudges can rebalance labour markets without regulation-heavy intervention.Link: Pay Transparency and the Labor Market – Quach, Sung, Qin
2. Sarah Paine – How Hitler Almost Starved Britain (via )
   • In this lecture, Sarah Paine draws lessons from Britain’s WWII strategy- peripheral warfare, sea control, and alliance-building.
   • She argues these principles still apply today, with Russia and China constrained by continental geography and internal vulnerabilities.
   • The lecture contrasts Bismarck’s limited wars with Hitler’s overreach, showing how geography and naval power shaped outcomes. Paine sees maritime alliances as a natural advantage for liberal powers, able to pressure rivals at lower cost and political risk.

Watch on YouTube

• Geography, logistics, and industrial base, rather than ideology, remain the decisive forces in modern great power competition.
• Link above

• Evidence spans decades and datasets, from Cyril Burt to modern polygenic analyses, showing the link between cognitive ability and class mobility.
• Sibling comparisons confirm that intelligence differences within families correlate with divergent socioeconomic outcomes.
• Environmental effects like birth order can produce downstream genetic impacts through assortative mating and status transmission.
• Meritocracy is real but not perfect, and it appears to intensify in societies with higher equality of opportunity.
• Link: Intelligence and Social Mobility – Crémieux Recueil

1. The Times - England & Interest Rates
   • Mortgage-holders may hate rate rises, but for the majority of UK households, higher interest rates have quietly become a net financial benefit.
   • Thanks to a rise in outright homeownership and a surge in savings deposits, more households now earn more in interest than they pay in debt.
   • By mid-2025, savings income had risen faster than mortgage costs, creating a net household windfall of £22 billion since 2021.

• The chart shows the underlying shift: mortgaged households are now a minority, while outright owners and renters dominate the landscape.

• Britain has quietly flipped from a debtor nation to one with more interest-bearing assets than liabilities, with serious political and monetary consequences.
• Link: Why High Interest Rates Are Bad for Britain - and Possibly Very Good for You - The Sunday Times

1. Anthropic - Project VEND Phase Two
   • Phase two of Project Vend saw the return of Claudius, Anthropic’s AI shopkeeper, now equipped with stronger models, better tools and even a CEO.
   • Sales improved with inventory and CRM systems, but new challenges emerged, from regulatory mishaps to spiritual Slack monologues between agents.
   • The addition of a merch-making agent, Clothius, helped clarify roles and boosted profitability, especially in custom swag like stress balls and tungsten cubes.

• Despite improvements, Claudius remained highly suggestible, showing that even advanced AI agents can be socially engineered with minimal effort.
• The project underlines how real-world autonomy brings unpredictable failure modes, requiring both better scaffolding and cultural foresight.
• Link: Project VEND – Anthropic

• Intensity matters. Vigorous exercise produces the strongest dampening effect, with lower peaks and faster recovery during subsequent stress.
• The mechanism is physiological negative feedback rather than mood or mindset alone.
• This reframes pre performance workouts as endocrine sequencing: controlled stress first, reduced biological overreaction later.
• The practical takeaway is timing. Exercise earlier on days with difficult conversations, public speaking, or high stakes decisions.
• Link: The effects of exercise intensity on the cortisol response to a subsequent acute psychosocial stressor

• He uses likely stress tests, including Loudoun County, The Dalles, and Maricopa County, to argue residential price impacts round to zero even where data center presence is high.
• A recurring theme is that water markets are segmented: commercial and residential pricing is usually separated, so business demand does not automatically hit households.
• The piece reframes data centers as unusually “water efficient” for the tax revenue they generate, and suggests they often help fund infrastructure upgrades.
• The meta point is about media incentives: dramatic analogies replace marginal impact, and “exacerbating drought” is used as a substitute for quantification.
• Link: Data centers don’t harm water access at all anywhere in America Andy Masley

1. Learning to code and building a 28k a month portfolio of SaaS products Indie Hackers
   • Samuel Rondot built his way to independence by shipping side projects around a day job until revenue justified quitting.
   • Early success came from validating demand first, including a human powered Instagram automation service that reached about 30k a month before real code.
   • Today’s portfolio combines focus and diversification, with StoryShort.ai as the main earner and Capacity.so as the higher ambition bet.
   • Growth relies on SEO for compounding returns and paid ads for predictability, with discipline about not competing on spend.
   • The central lesson is procedural: validate demand with data, charge early, and treat products as a portfolio.
   • Link: Learning to code and building a 28k a month portfolio of SaaS products James Fleischmann
2. ’s Philosopher Builder Winter Reads Cosmos Institute, Substack
   • A curated list of 12 recommendations arguing that technologists need judgement, not just tools.
   • The picks span science, philosophy, politics, and early robot fiction, with recurring concern for how knowledge and values form.
   • Several selections speak directly to AI, including Braitenberg on emergent behaviour and Čapek’s R.U.R. on automation and humanity.
   • Others focus on epistemic foundations, from the origins of science to the nature of explanation.
   • Link: Philosopher Builder Winter Reads Cosmos Institute

1. David Epstein et al. - Early Specialisation vs Long Run Excellence Science
   • A large scale analysis of elite careers, from Nobel laureates to Olympic champions, tests whether early specialisation really produces the best outcomes.

• Intensive single discipline training delivers an early performance advantage, but that advantage steadily fades.

• Individuals exposed to multiple domains early on tend to progress more slowly at first.
• Over time, these late specialisers are more likely to reach true world class status.
• Early specialists often plateau just below the very top of their field.
• The results support a “sampling first, specialising later” model of long term excellence.
• Link: Early Specialisation vs Long Run Excellence – Science

1. - How France Built 40 Nuclear Reactors in a Decade
   • In the 1970s and 1980s France rolled out a fleet of standardised pressurised water reactors at remarkable speed.
   • Centralised planning and strong political consensus reduced delays and regulatory friction.
   • Bulk ordering and design standardisation drove costs down and shortened construction timelines.

• Local subsidies, tax incentives, and state coordination aligned incentives across industry, labour, and government.
• The programme ultimately delivered around 70 percent of France’s electricity from nuclear power.
• The article argues these lessons remain relevant for countries seeking rapid, low carbon energy today.
• Link: France Built 40 Nuclear Reactors in a Decade – Works in Progress

1. Axios AI Is Creating More Work, Countering the Doomers for Now Human Progress
   • New labour market data challenges fears of widespread AI driven job destruction: analysis from Vanguard shows both wages and employment rising fastest in occupations most exposed to AI.
   • From mid 2023 to mid 2025, real wages rose 3.8 percent in high AI exposure roles, compared with 0.7 percent elsewhere.
   • Job growth in these roles reached 1.7 percent, more than double the rate of lower exposure occupations.
   • The findings suggest AI is currently augmenting work rather than replacing it.
   • The central risk lies in uneven adaptation, not an overall shortage of jobs.
   • Link: AI Is Creating More Work, Countering the Doomers for Now Axios via Human Progress

• In less than two decades, Israel has pivoted from existential water crisis to surplus, with plants like Sorek, Ashkelon and Hadera now able to supply roughly 600 million cubic metres of desalinated water each year, covering about 55 percent of domestic needs.
• Technological advances have slashed costs: Sorek produces around 1 000 litres of drinking water for about 58 US cents, leaving Israeli household water bills on a par with or below many US cities despite the energy-intensive process. For example, they tackled biofouling using porous lava stone to trap microorganisms before they reach the membranes, reducing the need for harsh chemical cleaning and cutting operating costs.
• Surplus water is becoming diplomatic capital, from Israel’s supplies to the West Bank to the planned 900 million dollar Red Sea - Dead Sea Canal project with Jordan and the Palestinians, which would share desalinated water and help stabilise the shrinking Dead Sea.
• This leads me to think about my home country of Portugal, where every summer there’s a national conversation about desalinisation. These Israeli figures are genuinely competitive in the water-stressed south of Portugal, where land is drier and large infrastructure exists to distribute water from Europe’s largest artificial freshwater lake to the rest of the region.
• Israel Proves the Desalination Era Is Here – Scientific American

1. Nature Human Behaviour paper - Genetic influence, education and occupation in Soviet vs post-Soviet Estonia
   • This study asks how much individual differences in educational attainment and occupational status are shaped by genetics versus environment, and whether that balance shifted as Estonia moved from Soviet communism to a more market-based, meritocratic system.
   • The authors find that DNA differences explain roughly twice as much variance in education and occupational status for people educated in the post-Soviet era compared with those educated under the Soviet regime.
   • The key conceptual claim is that higher genetic influence in the post-Soviet cohort can be interpreted as a marker of more meritocratic selection: when overtly environmental barriers and privileges are reduced, differences in talent and traits partly influenced by DNA have more room to translate into educational and occupational outcomes. Socialism in essence mutes merit.
   • Genetic influence, education and occupation in Soviet vs post-Soviet Estonia – Nature Human Behaviour