# Julien Reszka

> Personal blog on strategy, economics, engineering, and design.

## Blog posts

- [Rent and Pensions Eat Half of Your Disposable Income](https://julienreszka.com/blog/rent-and-pensions-eat-half-of-your-disposable-income/index.md): Pension contributions are usually measured against gross pay, rent against take home pay. Put both on the same basis and together they eat past half of it.
- [We Got Better at Keeping You Alive. Not at Keeping Healthy.](https://julienreszka.com/blog/we-got-better-at-keeping-you-alive-not-at-keeping-healthy/index.md): Global life expectancy keeps rising. Healthy life expectancy is not keeping pace, and the gap between the two has widened in 203 of 204 countries since 1990.
- [Your Pension Depends on Kids You Did Not Have](https://julienreszka.com/blog/your-pension-depends-on-kids-you-did-not-have/index.md): Pay-as-you-go pensions need a growing base of future workers to fund a shrinking one of retirees. Not having kids is free, and someone else pays twice.
- [Pensions Buy Fewer Babies. Cutting Them Costs Votes.](https://julienreszka.com/blog/pensions-buy-fewer-babies-cutting-them-costs-votes/index.md): Italy's 1990s pension cuts raised the birth rate among the workers who lost benefits. Cutting pensions further is exactly the reform democracies survive worst.
- [Ruling Is a Skill. Voting for It Is a Joke.](https://julienreszka.com/blog/ruling-is-a-skill-voting-for-it-is-a-joke/index.md): Elections measure who performs best under a spotlight, not who can allocate resources or absorb hard tradeoffs. Confusing the two breaks governance.
- [Difficult Conversations Don't Need to Be Messy](https://julienreszka.com/blog/difficult-conversations-don-t-need-to-be-messy/index.md): Memory is reconstructive. When someone recalls events differently, it feels like gaslighting. It usually isn't. Document first, then negotiate.
- [Bend Under Pressure, Not Under Nonsense](https://julienreszka.com/blog/bend-under-pressure-not-under-nonsense/index.md): Real pressure has a mechanism. Nonsense pressure is just social discomfort in disguise. Here is how to tell them apart and why it matters.
- [The More Power You Hold, the More You Owe](https://julienreszka.com/blog/the-more-power-you-hold-the-more-you-owe/index.md): Power does not earn trust, it creates a debt of proof. The COVID lab leak consensus shows what happens when officials are not held to that standard.
- [Stop Pasting Files Into Agent Prompts](https://julienreszka.com/blog/stop-pasting-files-into-agent-prompts/index.md): Paste a raw file into an agent prompt and half your context window is gone before a fix is written. One CSV line per issue beats 500 raw lines every time.
- [RSS Is Back. AI Agents Are Reading It.](https://julienreszka.com/blog/rss-is-back-ai-agents-are-reading-it/index.md): Google Reader died in 2013 and everyone called it. But RSS never stopped powering podcasting, and now AI agents need exactly what RSS does.
- [Structure Is What Makes an Interview Actually Work](https://julienreszka.com/blog/structure-is-what-makes-an-interview-actually-work/index.md): The study everyone cites to dismiss interviews has been corrected. The update is not that interviews work. It is that structure is what works.
- [Your Exit Route Determines Your Strategy](https://julienreszka.com/blog/your-exit-route-determines-your-strategy/index.md): Most founders pick a market, then hope for the right exit. That is backwards. The exit you want determines which market you enter and how to compete.
- [They're Required to Tell You How to Beat Them](https://julienreszka.com/blog/they-re-required-to-tell-you-how-to-beat-them/index.md): Incumbents are required by law to list everything that could kill them. Read those lists. Then build one of those things.
- [Know When to Stop, Pivot, or Double Down](https://julienreszka.com/blog/know-when-to-stop-pivot-or-double-down/index.md): Most founders ask 'is it worth building?' too late and with no framework. Three thresholds (comprehension, viability, growth) tell you when to stop.
- [Stop, Start, Continue Is a Brainstorm, Not a Retrospective](https://julienreszka.com/blog/stop-start-continue-is-a-brainstorm-not-a-retrospective/index.md): Stop/start/continue gives you a board of post-its and no decisions. Three strategic questions written before the meeting changes that.
- [Refactoring Is Procrastination in a Lab Coat](https://julienreszka.com/blog/refactoring-is-procrastination-in-a-lab-coat/index.md): 42% of dev time goes to technical debt. Most refactoring doesn't reduce that. It just moves it around while delaying real work.
- [Solve a Problem People Admit They Have](https://julienreszka.com/blog/solve-a-problem-people-admit-they-have/index.md): Strong retention but zero referrals is a diagnosis, not a mystery. Your customers have the problem. They just won't admit it in public.
- [Your Product Should Make the Buyer Look Good](https://julienreszka.com/blog/your-product-should-make-the-buyer-look-good/index.md): Owning a Rolex says more about you than it tells you the time. Products that make buyers look good get shared. That's not vanity, it's distribution.
- [Build the Referral Into the Product](https://julienreszka.com/blog/build-the-referral-into-the-product/index.md): Dropbox spent $388 acquiring customers worth $99, until referrals changed everything. Word-of-mouth doesn't just happen; it has to be designed.
- [If You Can't Describe It, No One Will Share It](https://julienreszka.com/blog/if-you-can-t-describe-it-no-one-will-share-it/index.md): Seven exposures before a message sticks. Most marketing wastes all seven by saying too much. The fix is compression, not more content.
- [Your Product Should Be Safe to Recommend](https://julienreszka.com/blog/your-product-should-be-safe-to-recommend/index.md): 83% of people act on recommendations from those they trust. The catch: they only recommend things they'd be comfortable defending.
- [Sticky Products Feel Personal](https://julienreszka.com/blog/sticky-products-feel-personal/index.md): Netflix's algorithm drives 80% of what users watch. The lesson: a product that feels like it knows you is one people don't leave.
- [The Cheapest Feature Is the One You Don't Build](https://julienreszka.com/blog/the-cheapest-feature-is-the-one-you-don-t-build/index.md): Most software features are never used. A simple severity filter (does anything depend on it? is there a workaround?) cuts them before they ship.
- [Anxiety Is Making You Dumber](https://julienreszka.com/blog/anxiety-is-making-you-dumber/index.md): Fear shrinks the prefrontal cortex and degrades the exact thinking you rely on for work. X is engineered to keep you in that state. The Stoics had the fix.
- [Your Sleep Schedule Is a Policy Document](https://julienreszka.com/blog/your-sleep-schedule-is-a-policy-document/index.md): The Dutch sleep 8 hours and work 32. Japan sleeps 7.5 and works 50. That gap isn't discipline; it's legislation.
- [Less Work, More Worry](https://julienreszka.com/blog/less-work-more-worry/index.md): Automation reduces stress at the task level and raises it at the existential level. The worry doesn't disappear. It just moves to harder questions.
- [The Better the Autopilot, the Worse the Pilot](https://julienreszka.com/blog/the-better-the-autopilot-the-worse-the-pilot/index.md): Automation doesn't make operators more careful. It makes them forget how to be. The more reliable the system, the less ready the human.
- [Automation Takes the Easy Jobs and Leaves You the Hard Ones](https://julienreszka.com/blog/automation-takes-the-easy-jobs-and-leaves-you-the-hard-ones/index.md): In theory, automation frees us for meaningful work. In practice, it filters out the easy tasks and leaves employees with a permanent queue of hard ones.
- [You Were Already Dependent. Automation Makes It Reliable.](https://julienreszka.com/blog/you-were-already-dependent-automation-makes-it-reliable/index.md): People cancel, get sick, and have their own agenda. Automated systems don't. The real case for automation is fewer humans in your critical path.
- [The Future of Work Is Getting Out of the Way](https://julienreszka.com/blog/the-future-of-work-is-getting-out-of-the-way/index.md): The future of work is not longer hours. It is learning when to step back, and designing systems so that when humans interfere, the damage is limited.
- [Robots Create More Jobs Than They Kill](https://julienreszka.com/blog/robots-create-more-jobs-than-they-kill/index.md): Machines destroying jobs is easy to debunk. Japan is among the most roboticised major economies and has one of the lowest unemployment rates in the G10.
- [Google Has No Idea If Your Page Is Good](https://julienreszka.com/blog/google-has-no-idea-if-your-page-is-good/index.md): After 25 years, Google still can't judge quality, so it defers to the crowd and makes you beg for backlinks instead of just writing something good.
- [I Quit Posting on Instagram for My Mental Health](https://julienreszka.com/blog/i-quit-posting-on-instagram-for-my-mental-health/index.md): The algorithm is a slot machine. Random rewards are more addictive than consistent ones. That's not a metaphor, it's behavioural science, and I was hooked.
- [Build With What's Already There](https://julienreszka.com/blog/build-with-what-s-already-there/index.md): Airbnb started with three air mattresses already in a closet. The business was not built from nothing. It was built from what was sitting unused.
- [Build for What Won't Change](https://julienreszka.com/blog/build-for-what-won-t-change/index.md): Jeff Bezos rarely answered 'what will change?' His more useful obsession was the opposite: what won't? Amazon was built on three bets that held for decades.
- [Delete It Before You Optimize It](https://julienreszka.com/blog/delete-it-before-you-optimize-it/index.md): Elon Musk's first rule: make requirements less dumb. Second: delete the step. Optimization is third, and most people start there.
- [What Actually Works for Dating in 2026](https://julienreszka.com/blog/what-actually-works-for-dating-in-2026/index.md): Dating apps are built like casinos. Here is what worked instead: a foreign language, a dance floor, and showing up somewhere new.
- [WebMCP Is the New Mobile-First](https://julienreszka.com/blog/webmcp-is-the-new-mobile-first/index.md): WebMCP brings agentic AI into the browser the same way mobile-first rewrote the web in 2012. The gap it opens is wide and most people are not looking at it yet.
- [The Only Policy Tool That Cannot Be Gamed](https://julienreszka.com/blog/the-only-policy-tool-that-cannot-be-gamed/index.md): Strict liability with mandatory insurance self-enforces, prices harm, resists capture, is free to the state, and funds the science. Most policies fail all five.
- [France Needs 45 Years to Grow Its Way Out](https://julienreszka.com/blog/france-needs-45-years-to-grow-its-way-out/index.md): Cutting spending when you already spend 57% of GDP gives you six times less growth than the same cut at 20%. France is on the wrong part of the curve.
- [Government Size Has No Sweet Spot](https://julienreszka.com/blog/government-size-has-no-sweet-spot/index.md): Cross-country data from 113 countries fits a power law better than the Armey Curve. Smaller governments consistently outgrow larger ones.
- [The Web Is Not a Safe Harbor From Platform Control](https://julienreszka.com/blog/the-web-is-not-a-safe-harbor-from-platform-control/index.md): Apple removed PWA capabilities in iOS 17.4 for EU users. The open web is not a safe harbor. Platforms control the runtime and will use that control.
- [Who Decided Europe Needed Replacing?](https://julienreszka.com/blog/who-decided-europe-needed-replacing/index.md): EU Commissioner Johansson said Europe needs 1 million legal migrants per year for demographic reasons. She said the quiet part out loud.
- [The Math Sales Gurus Won't Show You](https://julienreszka.com/blog/the-math-sales-gurus-won-t-show-you/index.md): 80% of buyers decide before they talk to a salesperson. The math shows exactly why pitching cold prospects is your most expensive mistake.
- [Your Risk Register Is Asking the Wrong Question](https://julienreszka.com/blog/your-risk-register-is-asking-the-wrong-question/index.md): Most risk frameworks ask what can go wrong. This one starts earlier: what does wrong mean here? It answers that structurally, the same way, for every context.
- [AI Will Soon Generate Video as Easily as Images](https://julienreszka.com/blog/ai-will-soon-generate-video-as-easily-as-images/index.md): Diffusion model outputs I generated in August 2021. The gap between clearly fake and indistinguishable from real is closing faster than anyone expects.
- [When Everyone Around You Goes Mad, Stay Normal](https://julienreszka.com/blog/when-everyone-around-you-goes-mad-stay-normal/index.md): A year into COVID restrictions, the hardest thing is not compliance. It is holding on to what is normal when everyone around you has stopped expecting it.
- [Mixture-of-Experts Routing Was Called a Stupid Idea](https://julienreszka.com/blog/mixture-of-experts-routing-was-called-a-stupid-idea/index.md): In the Lex Fridman Discord paper review sessions, Mixture-of-Experts routing is being dismissed as unscalable. Here is why I think the pushback is wrong.
- [5 Minutes to Fill. 2 Hours to Charge. EVs Have a Problem.](https://julienreszka.com/blog/5-minutes-to-fill-2-hours-to-charge-evs-have-a-problem/index.md): Refilling a petrol tank takes under 5 minutes. Charging an electric car takes over 2 hours. That gap is not a minor inconvenience.
- [The Wright Brothers Didn't Learn by Crashing](https://julienreszka.com/blog/the-wright-brothers-didn-t-learn-by-crashing/index.md): The Wrights did not invent flight. They invented controlled flight. The difference was a wind tunnel and 200 wing tests before any aircraft was built.
- [Love Score Was Banned for Reading SMS Metadata On-Device](https://julienreszka.com/blog/love-score-was-banned-for-reading-sms-metadata-on-device/index.md): Google banned Love Score from the Play Store. It never touched the internet. All SMS metadata analysis ran on device. That did not matter.
- [Video Won the Web. Most Sites Haven't Noticed Yet.](https://julienreszka.com/blog/video-won-the-web-most-sites-haven-t-noticed-yet/index.md): In France's Alexa top 50, half the sites put video first. 4G removed the last excuse. If your site doesn't lead with video, you're already behind.
- [I Decided Not to Join YCombinator](https://julienreszka.com/blog/i-decided-not-to-join-ycombinator/index.md): After joining Startup School, I passed on YC itself. The forum culture told me more about the program than the pitch deck did.
- [I Joined Startup School to Build the Trusted Map of Events](https://julienreszka.com/blog/i-joined-startup-school-to-build-the-trusted-map-of-events/index.md): I joined YC Startup School to build a trusted map of every event, with calculated uncertainty about who has the authority to call one real.
- [Intelligence as a Nine-Node Cycle of Interpretation](https://julienreszka.com/blog/intelligence-as-a-nine-node-cycle-of-interpretation/index.md): The model: a nine-node cycle with three buffer spaces and six processing modules. Each domain maps to a specific imperfection type and transaction mode.
- [Information Has Six Imperfections and None Can Be Eliminated](https://julienreszka.com/blog/information-has-six-imperfections-and-none-can-be-eliminated/index.md): Every edge in a reasoning cycle carries imperfect information. The six forms cannot be removed, only redistributed. Policy determines the redistribution.
- [The Three Sovereignties of Interpretive Power](https://julienreszka.com/blog/the-three-sovereignties-of-interpretive-power/index.md): Every interpretation has a sovereign, one of three modes. I am mapping theocratic, democratic, and autocratic authority across nine temporal dimensions.
- [Grounding Is a Governance Problem, Not a Data Problem](https://julienreszka.com/blog/grounding-is-a-governance-problem-not-a-data-problem/index.md): Working on an AGI architecture. The most original part: grounding is not a data problem. It is a governance problem.
- [I Got Into 42 Paris](https://julienreszka.com/blog/i-got-into-42-paris/index.md): After one month competing in the Piscine, I was accepted to 42 Paris. Here is what that month actually looked like.
- [Translating a Book Is the Best Way to Learn It](https://julienreszka.com/blog/translating-a-book-is-the-best-way-to-learn-it/index.md): Reading a chapter twice changes almost nothing. Translating it forces you to understand every sentence. I am doing this now with Jeff Heaton's AI book.
- [Is Mass Immigration a Moral Obligation? V4 says No](https://julienreszka.com/blog/is-mass-immigration-a-moral-obligation-v4-says-no/index.md): The V4 refused mandatory EU quotas. Countries that bombed Libya should not guilt-trip those that did not. Ordinary Europeans were never asked either.
- [The Shift to Mobile Created My First Freelance Opportunity](https://julienreszka.com/blog/the-shift-to-mobile-created-my-first-freelance-opportunity/index.md): The move to mobile left thousands of old desktop-only sites broken. I turned that into my first serious freelance work.
- [The GAN Paper Turned Me Toward Generative Design](https://julienreszka.com/blog/the-gan-paper-turned-me-toward-generative-design/index.md): The GAN paper showed a network generating images that do not exist. I stopped my studies at Penninghen and reoriented toward generative design.
- [Love Score Charted My Contacts on Balance and Passion](https://julienreszka.com/blog/love-score-charted-my-contacts-on-balance-and-passion/index.md): Thomas Jannaud and I released Love Score for Android. It reads SMS metadata and maps every contact on two axes: balance and passion.
- [The Upcoming War in Eastern Europe](https://julienreszka.com/blog/the-upcoming-war-in-eastern-europe/index.md): The Normandy summit produced a photo and a dinner. It produced no ceasefire because the two parties could not agree on what the conflict even was.
- [I Bought Bitcoin at the Inauguration of La Maison du Bitcoin](https://julienreszka.com/blog/i-bought-bitcoin-at-the-inauguration-of-la-maison-du-bitcoin/index.md): La Maison du Bitcoin opened in Paris today. I bought a small amount of bitcoin at the inauguration and had no idea what to do with it next.
- [I Am Going to Study Geopolitics of Central Europe](https://julienreszka.com/blog/i-am-going-to-study-geopolitics-of-central-europe/index.md): Russia annexed Crimea and most people I know are confused. I was not. I have Polish roots and I have been studying this region. The structure was legible.
- [The 3D Printshow at the Louvre Felt Like the Future](https://julienreszka.com/blog/the-3d-printshow-at-the-louvre-felt-like-the-future/index.md): At the 3D Printshow in the Carousel du Louvre I saw printed bones, printed food, and printed aircraft parts. None of it felt like a demo.
- [I Joined Penninghen to Study Design and Art Direction](https://julienreszka.com/blog/i-joined-penninghen-to-study-design-and-art-direction/index.md): I started at Esag Penninghen in Paris today. The school trains art directors. I want to understand how good visual communication actually works.
- [A Free Tool Called Fluidui Made Me a UI Designer](https://julienreszka.com/blog/a-free-tool-called-fluidui-made-me-a-ui-designer/index.md): Fluidui let me click through my own mockups the same way a real user would. That feedback loop was faster than anything I had tried before.
- [Felt Like Ezio in Florence](https://julienreszka.com/blog/felt-like-ezio-in-florence/index.md): I visited Florence in July 2012 having already spent 30 hours there in 1486. The city was exactly where I left it.
- [The Revolution Will Be Tweeted](https://julienreszka.com/blog/the-revolution-will-be-tweeted/index.md): Twitter asks you to name yourself, state your beliefs, and list your associates. Then it makes all of it searchable. It is a registration form.
- [War in Libya. What's in It for Us?](https://julienreszka.com/blog/war-in-libya-what-s-in-it-for-us/index.md): France is going to war in Libya. Ask who benefits: Sarkozy, Total, the rebels. Then ask who pays: you do.
- [Wait. Leonardo Da Vinci Was Real?](https://julienreszka.com/blog/wait-leonardo-da-vinci-was-real/index.md): I thought Leonardo in Assassin's Creed II was a made-up character. Then I looked him up.