Notes on software craftsmanship.https://www.mathieueveillard.com/blog/enhttps://www.mathieueveillard.com/blog/priorites/https://www.mathieueveillard.com/blog/priorites/Good modularity lets you tolerate crummy code locally and fix it later without breaking everything.Wed, 08 Jul 2026 00:00:00 GMTModularityCEOBest ofhttps://www.mathieueveillard.com/blog/qa/https://www.mathieueveillard.com/blog/qa/No, QA is not your designated tester. “QA” is a process, not a role: its real job is to help the team grow.Wed, 24 Jun 2026 00:00:00 GMTOrganizationhttps://www.mathieueveillard.com/blog/processus-d-ecriture/https://www.mathieueveillard.com/blog/processus-d-ecriture/Behind the scenes of my weekly writing: ideation, the writing process, the role of AI, and next steps for these articles.Wed, 17 Jun 2026 00:00:00 GMTWritinghttps://www.mathieueveillard.com/blog/taux-journalier/https://www.mathieueveillard.com/blog/taux-journalier/When the client’s needs become clear over time, the daily rate is the most appropriate solution. But how do you determine it?Wed, 10 Jun 2026 00:00:00 GMTWorkhttps://www.mathieueveillard.com/blog/loi-de-linstrument-llm/https://www.mathieueveillard.com/blog/loi-de-linstrument-llm/LLMs are our new hammers. But the heart of the field isn’t a nail: that’s where we need to keep our focus.Wed, 03 Jun 2026 00:00:00 GMTAI/LLMhttps://www.mathieueveillard.com/blog/ai-brain-fry/https://www.mathieueveillard.com/blog/ai-brain-fry/More AI, more code to review, more context switching, more fatigue: the limit is the human factor.Wed, 27 May 2026 00:00:00 GMTAI/LLMhttps://www.mathieueveillard.com/blog/llm-et-agilite-pourquoi-les-opposer/https://www.mathieueveillard.com/blog/llm-et-agilite-pourquoi-les-opposer/Just because we develop faster, does that mean we no longer need Agility? This idea betrays a misunderstanding of what Agility is.Wed, 13 May 2026 00:00:00 GMTAI/LLMAgile and Leanhttps://www.mathieueveillard.com/blog/dont-repeat-yourself/https://www.mathieueveillard.com/blog/dont-repeat-yourself/It’s better to have a little intentional duplication than premature abstraction that mixes business rules that have no business being together.Wed, 29 Apr 2026 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/que-signifie-etre-un-expert/https://www.mathieueveillard.com/blog/que-signifie-etre-un-expert/Your favorite LLM is the perfect companion to ask all your embarrassing questions. But then again, is there really any reason to be embarrassed when you don’t know something?Wed, 22 Apr 2026 00:00:00 GMTAI/LLMhttps://www.mathieueveillard.com/blog/llm-manager/https://www.mathieueveillard.com/blog/llm-manager/Coding with an LLM is like managing a team: you have to balance delegation and move forward in small steps.Wed, 08 Apr 2026 00:00:00 GMTAI/LLMCraftsmanshiphttps://www.mathieueveillard.com/blog/bullying/https://www.mathieueveillard.com/blog/bullying/Sharing your ideas on LinkedIn exposes you to aggressive comments. How should you deal with trolls?Wed, 25 Mar 2026 00:00:00 GMTRantPersonalhttps://www.mathieueveillard.com/blog/generation-llm/https://www.mathieueveillard.com/blog/generation-llm/For a young developer who has everything to learn, LLMs are false friends because they discourage the effort to learn.Wed, 04 Mar 2026 00:00:00 GMTAI/LLMWorkhttps://www.mathieueveillard.com/blog/bug-erreur-cas-nominal/https://www.mathieueveillard.com/blog/bug-erreur-cas-nominal/When should you throw an exception, return an error, or model the absence of an error? The answer lies in the business intent.Tue, 24 Feb 2026 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/design-system/https://www.mathieueveillard.com/blog/design-system/Before components, tokens. How to structure a coherent Design System using a well-thought-out token architecture.Wed, 11 Feb 2026 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/architecture-hexagonale-vs-orm/https://www.mathieueveillard.com/blog/architecture-hexagonale-vs-orm/An ORM lets you build the domain on entities it exposes, which are directly mapped to the database. This is the opposite of Hexagonal Architecture.Wed, 21 Jan 2026 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/union-types/https://www.mathieueveillard.com/blog/union-types/TypeScript is often used only superficially. This is particularly true for Union Types, which help prevent inconsistent states.Wed, 14 Jan 2026 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/result/https://www.mathieueveillard.com/blog/result/Exceptions are not meant to handle predictable errors. Discover the Result type, an alternative to try/catch.Wed, 17 Dec 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/property-based-testing/https://www.mathieueveillard.com/blog/property-based-testing/PBT verifies that a business invariant is always satisfied regardless of the parameters and the return value of the function being tested.Wed, 10 Dec 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/5-ans/https://www.mathieueveillard.com/blog/5-ans/Reflections on five years of independence: intellectual stimulation, learning, writing, and freedom.Wed, 03 Dec 2025 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/radicalite/https://www.mathieueveillard.com/blog/radicalite/Radicalism is the refusal to distort words—and thus the refusal to compromise. It is divisive, of course, but that is for the best.Wed, 26 Nov 2025 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/whatever-works/https://www.mathieueveillard.com/blog/whatever-works/A call for pragmatism in software development: avoid dogma, observe what works, and leave room for doubt.Wed, 12 Nov 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/conception-fonctionnelle/https://www.mathieueveillard.com/blog/conception-fonctionnelle/High-quality software is well-designed software before it is well-built software. Let’s explore together how to go about this.Wed, 29 Oct 2025 00:00:00 GMTProducthttps://www.mathieueveillard.com/blog/indicateurs-qualite-logicielle/https://www.mathieueveillard.com/blog/indicateurs-qualite-logicielle/Measure an outcome rather than an output. This way, you empower your teams and align them with your company’s goals.Tue, 14 Oct 2025 00:00:00 GMTOrganizationhttps://www.mathieueveillard.com/blog/agilite-prime-de-risque/https://www.mathieueveillard.com/blog/agilite-prime-de-risque/The problem is that the benchmark (Waterfall) leads to software that doesn’t meet users’ needs…Wed, 08 Oct 2025 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/alternative-aux-estimations/https://www.mathieueveillard.com/blog/alternative-aux-estimations/Don’t ask, “How long will this take?” Instead, ask yourself if you can break your work down into even smaller pieces.Wed, 01 Oct 2025 00:00:00 GMTAgile and LeanCEOBest ofhttps://www.mathieueveillard.com/blog/la-qualite-logicielle-c-est-aller-vite-longtemps/https://www.mathieueveillard.com/blog/la-qualite-logicielle-c-est-aller-vite-longtemps/Moving fast is easy. Maintaining that pace for years is more difficult and is the true mark of software quality.Wed, 24 Sep 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/la-qualite-logicielle-est-trop-importante-pour-etre-laissee-a-votre-cto/https://www.mathieueveillard.com/blog/la-qualite-logicielle-est-trop-importante-pour-etre-laissee-a-votre-cto/Producing high-quality software involves organizational aspects that go beyond technology and can undermine the CTO’s efforts.Wed, 17 Sep 2025 00:00:00 GMTCEOOrganizationhttps://www.mathieueveillard.com/blog/roi-modularisation/https://www.mathieueveillard.com/blog/roi-modularisation/A lack of modularity is costly. Investing in a modular architecture protects your software and prevents massive financial losses.Wed, 10 Sep 2025 00:00:00 GMTModularityCEOhttps://www.mathieueveillard.com/blog/bugs/https://www.mathieueveillard.com/blog/bugs/It’s easy to blame developers. But bugs also stem from design, organization, and culture.Wed, 03 Sep 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/domain-driven-design-un-contexte-un-model/https://www.mathieueveillard.com/blog/domain-driven-design-un-contexte-un-model/A model is never a faithful representation of reality, but an abstraction designed for a specific purpose. A model exists only through its use.Wed, 27 Aug 2025 00:00:00 GMTModularityCraftsmanshiphttps://www.mathieueveillard.com/blog/optimisation-algorithmique/https://www.mathieueveillard.com/blog/optimisation-algorithmique/An example of algorithm optimization (the skyscraper game) and the lessons that can be learned from it. Pareto’s Law applies fully.Wed, 20 Aug 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/effectuation/https://www.mathieueveillard.com/blog/effectuation/Effectuation, theorized by Saras Sarasvathy, takes the opposite approach to the entrepreneurial myth: here, the goal is defined based on the available resources.Wed, 02 Jul 2025 00:00:00 GMTReading listhttps://www.mathieueveillard.com/blog/recruter-profils-tech/https://www.mathieueveillard.com/blog/recruter-profils-tech/Here are a few pieces of advice, drawn from my experience working with companies, that I wish I’d had back when I was a manager.Wed, 25 Jun 2025 00:00:00 GMTCEOhttps://www.mathieueveillard.com/blog/mvp-une-notion-contextuelle/https://www.mathieueveillard.com/blog/mvp-une-notion-contextuelle/Some MVPs cost 10,000 euros; others, 10 million euros. The goal is the same—to acquire real users—but it all depends on the market.Wed, 11 Jun 2025 00:00:00 GMTAgile and LeanProducthttps://www.mathieueveillard.com/blog/moi-je-fais-le-dev-et-toi-tu-fais-la-qualite/https://www.mathieueveillard.com/blog/moi-je-fais-le-dev-et-toi-tu-fais-la-qualite/The road to hell is paved with good intentions, and your Quality Department is no exception: it’s impossible to distinguish between “doing” and “doing better.”Wed, 04 Jun 2025 00:00:00 GMTOrganizationhttps://www.mathieueveillard.com/blog/jit-learning/https://www.mathieueveillard.com/blog/jit-learning/When it comes to IT, you’re bound to be playing catch-up. For greater peace of mind, discover Just-In-Time Learning.Wed, 28 May 2025 00:00:00 GMTLearninghttps://www.mathieueveillard.com/blog/editeurs-de-logiciels-b2b-votre-client-vous-paie-mais-il-vous-tue/https://www.mathieueveillard.com/blog/editeurs-de-logiciels-b2b-votre-client-vous-paie-mais-il-vous-tue/Co-creating your product with your first customers is a good thing. However, that doesn’t mean giving in to all their requests.Wed, 21 May 2025 00:00:00 GMTCEOProducthttps://www.mathieueveillard.com/blog/insuffler-le-changement/https://www.mathieueveillard.com/blog/insuffler-le-changement/To bring about lasting change, it’s better to persuade than to order. However, this change takes time and requires self-directed individuals.Wed, 30 Apr 2025 00:00:00 GMTAgile and LeanCoachinghttps://www.mathieueveillard.com/blog/architecture-hexagonale/https://www.mathieueveillard.com/blog/architecture-hexagonale/Hexagonal Architecture, formalized by Alistair Cockburn, aims to isolate the domain. It is based on dependency inversion and dependency injection.Wed, 23 Apr 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/ticket-un-jour-bullshit-toujours/https://www.mathieueveillard.com/blog/ticket-un-jour-bullshit-toujours/User Story or technical task? Behind a battle of words lies the trade-off between today’s value and tomorrow’s.Wed, 16 Apr 2025 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/l-obsession-du-service-client/https://www.mathieueveillard.com/blog/l-obsession-du-service-client/When “users” are mistreated by a company in a monopoly position, there is cause to start a competing business.Wed, 02 Apr 2025 00:00:00 GMTReading listAgile and Leanhttps://www.mathieueveillard.com/blog/typologies-de-missions/https://www.mathieueveillard.com/blog/typologies-de-missions/Even though every project is unique, it’s still possible to identify common types, starting with the “firefighter” project: “Help, everything’s on fire!”Wed, 26 Mar 2025 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/12-facons-originales-de-foirer-vos-sprints/https://www.mathieueveillard.com/blog/12-facons-originales-de-foirer-vos-sprints/"It’s good to learn from your mistakes. It’s better to learn from the mistakes of others." Warren Buffett is talking about investing; I’m talking about sprints.Wed, 19 Mar 2025 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/pourquoi-j-ecris/https://www.mathieueveillard.com/blog/pourquoi-j-ecris/I’ve been writing every week for over two years now. This is an opportunity to reflect on what truly motivates me, beyond the simple pleasure of sharing my experience.Wed, 12 Mar 2025 00:00:00 GMTWritinghttps://www.mathieueveillard.com/blog/command-query-responsibility-segregation/https://www.mathieueveillard.com/blog/command-query-responsibility-segregation/CQRS is based on the idea of distinguishing between write and read models when operations are highly asymmetric. Use sparingly.Wed, 05 Mar 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/100-code-coverage-la-course-a-l-echalote/https://www.mathieueveillard.com/blog/100-code-coverage-la-course-a-l-echalote/This metric isn’t very useful if you don’t know what it represents… However, it’s still interpretable—especially when it’s low!Wed, 19 Feb 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/waterfall-la-recette-de-l-echec/https://www.mathieueveillard.com/blog/waterfall-la-recette-de-l-echec/Sequential methodologies do not work for business IT, primarily because of the tunnel effect. The alternative? Agility.Wed, 12 Feb 2025 00:00:00 GMTAgile and LeanCEOhttps://www.mathieueveillard.com/blog/50-shades-of-tests/https://www.mathieueveillard.com/blog/50-shades-of-tests/Not all tests fit into a single test pyramid. Several aspects must be considered: purpose, granularity, and assertion methods.Wed, 05 Feb 2025 00:00:00 GMTCraftsmanshipBest ofhttps://www.mathieueveillard.com/blog/the-very-best-of/https://www.mathieueveillard.com/blog/the-very-best-of/To mark the 100th issue of this newsletter, here’s a selection of 10 articles—some of your favorites and some of my personal favorites.Wed, 29 Jan 2025 00:00:00 GMThttps://www.mathieueveillard.com/blog/une-architecture-qui-laisse-des-portes-ouvertes/https://www.mathieueveillard.com/blog/une-architecture-qui-laisse-des-portes-ouvertes/"The job of an architect is to build a structure that allows decisions to be delayed as long as possible": 5 examples illustrating Uncle Bob’s point.Wed, 22 Jan 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/tests-end-to-end-comment-demarrer-du-bon-pied/https://www.mathieueveillard.com/blog/tests-end-to-end-comment-demarrer-du-bon-pied/End-to-end tests should be used sparingly, as they are costly to write (Page Model) and costly to run. Here’s how to proceed.Wed, 08 Jan 2025 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/mes-valeurs/https://www.mathieueveillard.com/blog/mes-valeurs/Joy, humility, rigor, and action. These are the values that drive me, both in my daily life and at work—the two cannot be separated.Wed, 01 Jan 2025 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/la-retrospective-adn-de-l-agilite/https://www.mathieueveillard.com/blog/la-retrospective-adn-de-l-agilite/If you had to keep just one thing from Agility, keep the retrospective. As a forum for continuous improvement, it paves the way for problem-solving.Wed, 25 Dec 2024 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/un-x-qui-fait-du-code/https://www.mathieueveillard.com/blog/un-x-qui-fait-du-code/For me, being a Polytech graduate meant an obligation to hold high-level positions, and part of me aspired to that out of a need for recognition.Wed, 18 Dec 2024 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/produit-quand-on-sattache-a-son-bebe/https://www.mathieueveillard.com/blog/produit-quand-on-sattache-a-son-bebe/We take care of a product, we help it grow, we tend to it day after day just as we care for a baby. We become attached to it, and that’s perfectly fine.Wed, 27 Nov 2024 00:00:00 GMTPersonalProductCraftsmanshiphttps://www.mathieueveillard.com/blog/markup-hold-up/https://www.mathieueveillard.com/blog/markup-hold-up/The intermediary brings their full value to the signing of the contract, not to every day of the assignment. Their compensation should therefore be a flat fee.Wed, 09 Oct 2024 00:00:00 GMTWorkRanthttps://www.mathieueveillard.com/blog/la-qualite-logicielle-une-affaire-de-code/https://www.mathieueveillard.com/blog/la-qualite-logicielle-une-affaire-de-code/Software quality isn’t just about code: it’s a matter of product, agility, organization, and people, before it is a matter of technical expertise.Wed, 02 Oct 2024 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/coach-ou-consultant/https://www.mathieueveillard.com/blog/coach-ou-consultant/While a consultant provides specific answers, a coach helps their client find their own answers. These are different yet complementary approaches.Wed, 11 Sep 2024 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/architecture-decision-record/https://www.mathieueveillard.com/blog/architecture-decision-record/ADR helps streamline a team’s architectural decisions and prevents them from being constantly called into question.Wed, 10 Jul 2024 00:00:00 GMTCraftsmanshipAgile and Leanhttps://www.mathieueveillard.com/blog/si-tu-veux-programmer-mieux-arrete-de-programmer-pendant-2-ans/https://www.mathieueveillard.com/blog/si-tu-veux-programmer-mieux-arrete-de-programmer-pendant-2-ans/In our eagerness to master our craft, we sometimes come to view computer science as an end in itself. Yet it is merely a means. A means to what end?Wed, 19 Jun 2024 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/dont-write-code-that-guesses-the-future/https://www.mathieueveillard.com/blog/dont-write-code-that-guesses-the-future/Avoid over-anticipating: don’t lay the groundwork for future features; they remain hypothetical. Instead, write code that can evolve.Wed, 12 Jun 2024 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/les-esn-parasites-de-linformatique/https://www.mathieueveillard.com/blog/les-esn-parasites-de-linformatique/Few digital services companies possess true expertise. The majority sell precarious employment conditions to end clients, which suits them just fine.Wed, 22 May 2024 00:00:00 GMTWorkRantBest ofhttps://www.mathieueveillard.com/blog/it-darwin-awards/https://www.mathieueveillard.com/blog/it-darwin-awards/8 ideas that are frankly ridiculous—and yet so widespread—when it comes to software development… Do yourself a favor: read this!Wed, 15 May 2024 00:00:00 GMThttps://www.mathieueveillard.com/blog/seule-lagilite-na-aucun-sens/https://www.mathieueveillard.com/blog/seule-lagilite-na-aucun-sens/Agility is the art of “how,” Product Management that of “what.” One without the other is pointless: they are two sides of the same coin.Wed, 24 Apr 2024 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/un-contexte-de-presentation/https://www.mathieueveillard.com/blog/un-contexte-de-presentation/You don’t address all users in the same way. Each persona has its own language—and therefore its own context—and its own BFF (Backend For Frontend).Wed, 17 Apr 2024 00:00:00 GMTModularityCraftsmanshiphttps://www.mathieueveillard.com/blog/ecologie-et-qualite-logicielle/https://www.mathieueveillard.com/blog/ecologie-et-qualite-logicielle/Ecology and software quality share Kant’s principle of universality: my action can only be good if everyone can act as I do.Wed, 27 Mar 2024 00:00:00 GMTPersonalCraftsmanshiphttps://www.mathieueveillard.com/blog/you-build-it-you-run-it/https://www.mathieueveillard.com/blog/you-build-it-you-run-it/This phrase, a DevOps mantra, is rooted in common sense. Yet the organization sometimes resists its implementation. CEOs, lay the groundwork.Wed, 20 Mar 2024 00:00:00 GMTCraftsmanshipOrganizationhttps://www.mathieueveillard.com/blog/culture-lean/https://www.mathieueveillard.com/blog/culture-lean/“Lean is not a production system; it’s a learning system”: that line gave me the foothold I needed to grok Lean.Wed, 24 Jan 2024 00:00:00 GMTReading listAgile and Leanhttps://www.mathieueveillard.com/blog/refactoring-eviter-leffet-tunnel/https://www.mathieueveillard.com/blog/refactoring-eviter-leffet-tunnel/Until everything is done, it’s as if nothing has been done. To avoid a refactoring’s tunnel effect: the Strangler Fig pattern, which lets the old and the new coexist.Wed, 10 Jan 2024 00:00:00 GMTRefactoringCraftsmanshiphttps://www.mathieueveillard.com/blog/du-courage-pour-2024/https://www.mathieueveillard.com/blog/du-courage-pour-2024/Beyond technology and methodology, it’s our values that drive us. For 2024, I wish you courage: to aim high, to question, to ask for help.Wed, 03 Jan 2024 00:00:00 GMThttps://www.mathieueveillard.com/blog/coacher-le-coach/https://www.mathieueveillard.com/blog/coacher-le-coach/There is always a risk of doing harm while trying to do good. A coach, like other support professionals, should be supervised.Wed, 13 Dec 2023 00:00:00 GMTCoachingPersonalhttps://www.mathieueveillard.com/blog/modular-monolith-is-the-new-microservices/https://www.mathieueveillard.com/blog/modular-monolith-is-the-new-microservices/You probably don’t need these microservices, which are so difficult to deploy. The monolith—provided it’s modular—is right for you.Wed, 06 Dec 2023 00:00:00 GMTModularityCraftsmanshipBest ofhttps://www.mathieueveillard.com/blog/walking-skeleton/https://www.mathieueveillard.com/blog/walking-skeleton/The Walking Skeleton aims to lay a solid foundation for reaching the MVP while minimizing technical debt. It’s a step worth formalizing.Wed, 29 Nov 2023 00:00:00 GMTAgile and LeanCraftsmanshipBest ofhttps://www.mathieueveillard.com/blog/freelance-une-affaire-de-gros-sous/https://www.mathieueveillard.com/blog/freelance-une-affaire-de-gros-sous/Going freelance is an opportunity to double your income… or not. It all depends on your life plan. An account of a personal experience.Wed, 22 Nov 2023 00:00:00 GMTPersonalBest ofhttps://www.mathieueveillard.com/blog/example-mapping/https://www.mathieueveillard.com/blog/example-mapping/It would be a mistake to believe that functional design is the sole responsibility of the PM: we think more clearly when working together and using concrete examples.Wed, 15 Nov 2023 00:00:00 GMTAgile and LeanCraftsmanshiphttps://www.mathieueveillard.com/blog/trunk-based-development/https://www.mathieueveillard.com/blog/trunk-based-development/Trunk-Based Development, which stems directly from Extreme Programming, is an excellent alternative to GitFlow, but be sure to thoroughly review the prerequisites.Wed, 08 Nov 2023 00:00:00 GMTCraftsmanshipAgile and Leanhttps://www.mathieueveillard.com/blog/poc-vs-mvp/https://www.mathieueveillard.com/blog/poc-vs-mvp/A POC validates a marketing or technical idea, while an MVP aims to acquire your first users.Wed, 25 Oct 2023 00:00:00 GMTProductAgile and Leanhttps://www.mathieueveillard.com/blog/projet-vs-produit-les-mots-ont-leur-importance/https://www.mathieueveillard.com/blog/projet-vs-produit-les-mots-ont-leur-importance/A project exists because we envision a goal to be achieved. A product has no end and evolves based on user feedback.Wed, 18 Oct 2023 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/scrum-un-framework-pour-experts-de-lagilite/https://www.mathieueveillard.com/blog/scrum-un-framework-pour-experts-de-lagilite/My main criticism of Scrum is that it says nothing about functional design. If you want it to work, it’s up to you to fill in the gaps.Wed, 11 Oct 2023 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/bounded-contexts-101/https://www.mathieueveillard.com/blog/bounded-contexts-101/2 common mistakes in dividing into Bounded Contexts: dividing by technical layers and dividing by entities. Think action verbs!Wed, 04 Oct 2023 00:00:00 GMTModularityCraftsmanshipOrganizationhttps://www.mathieueveillard.com/blog/marathon-de-berlin-2023-2h27/https://www.mathieueveillard.com/blog/marathon-de-berlin-2023-2h27/I’m the same person at work and when I’m running. So today, I’m sharing a story about myself through a defining moment in my life as a runner.Wed, 27 Sep 2023 00:00:00 GMTPersonalBest ofhttps://www.mathieueveillard.com/blog/plus-personne-ne-sait-ce-quest-une-user-story/https://www.mathieueveillard.com/blog/plus-personne-ne-sait-ce-quest-une-user-story/"As a user, I want to connect to the database, so that I’m connected to the database." Great, or not: we have to be able to do better than that.Wed, 20 Sep 2023 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/les-faux-progres/https://www.mathieueveillard.com/blog/les-faux-progres/Every feature added to a product increases its complexity and raises the risk of errors. So be absolutely certain of the value it adds.Wed, 30 Aug 2023 00:00:00 GMTProducthttps://www.mathieueveillard.com/blog/un-objet-nest-pas-ce-que-vous-croyez/https://www.mathieueveillard.com/blog/un-objet-nest-pas-ce-que-vous-croyez/Building an object means starting with its behavior. The data it encapsulates is derived from that and constitutes an implementation detail.Wed, 23 Aug 2023 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/un-peu-de-sens-dans-un-monde-de-brutes/https://www.mathieueveillard.com/blog/un-peu-de-sens-dans-un-monde-de-brutes/When a simple interaction with my neighbor Huguette reminds us that not everything can be understood through the lens of computer science…Wed, 19 Jul 2023 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/bug-or-feature/https://www.mathieueveillard.com/blog/bug-or-feature/In a legacy system on which many other systems depend, fixing a bug is not always recommended. It’s better to isolate it and maintain it.Wed, 12 Jul 2023 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/je-ne-vous-vendrai-pas-de-formation-clean-code/https://www.mathieueveillard.com/blog/je-ne-vous-vendrai-pas-de-formation-clean-code/"Clean Code" is a reference book: reading it linearly, from A to Z, would make little sense. You need to read it, experiment with the concepts, and revisit it frequently.Wed, 14 Jun 2023 00:00:00 GMTCoachingCraftsmanshiphttps://www.mathieueveillard.com/blog/un-an-deja/https://www.mathieueveillard.com/blog/un-an-deja/Looking back on a year of writing: the format that has emerged, the feedback I’ve received, and the deep motivation behind these posts.Wed, 07 Jun 2023 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/librairie-vs-framework/https://www.mathieueveillard.com/blog/librairie-vs-framework/You call a library, but it’s the framework that calls you. The difference is inversion of control.Wed, 31 May 2023 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/rehabiliter-la-perfection/https://www.mathieueveillard.com/blog/rehabiliter-la-perfection/It is, after all, somewhat paradoxical that perfection has become a dirty word. Don’t abandon it, but strive toward it through continuous improvement.Wed, 24 May 2023 00:00:00 GMTRantLearningPersonalhttps://www.mathieueveillard.com/blog/estimating-or-not-that-is-the-question/https://www.mathieueveillard.com/blog/estimating-or-not-that-is-the-question/Rather than making estimates—which are as accurate as a broken clock (which is right twice a day)—break your work down into smaller tasks.Wed, 17 May 2023 00:00:00 GMTAgile and Leanhttps://www.mathieueveillard.com/blog/la-malediction-des-ingenieurs/https://www.mathieueveillard.com/blog/la-malediction-des-ingenieurs/Engineers, too busy wondering if they’ll measure up, overlook a more fundamental question: What is the purpose of their work?Wed, 03 May 2023 00:00:00 GMTPersonalhttps://www.mathieueveillard.com/blog/si-vous-croyez-savoir-vous-ne-savez-pas/https://www.mathieueveillard.com/blog/si-vous-croyez-savoir-vous-ne-savez-pas/Bloom’s revised taxonomy offers a detailed description of the levels of knowledge. An autobiographical example is provided to help you better understand it.Wed, 26 Apr 2023 00:00:00 GMTLearninghttps://www.mathieueveillard.com/blog/oh-le-beau-framework-maison/https://www.mathieueveillard.com/blog/oh-le-beau-framework-maison/If you’re thinking about creating a custom framework, think twice: some have tried it, and they’ve had their share of problems!Wed, 19 Apr 2023 00:00:00 GMTOrganizationhttps://www.mathieueveillard.com/blog/coaching-is-language-agnostic/https://www.mathieueveillard.com/blog/coaching-is-language-agnostic/Working on software quality means working on architectures, paradigms, and methodologies—particularly clean code. The programming language doesn’t matter.Wed, 12 Apr 2023 00:00:00 GMTCoachingCraftsmanshiphttps://www.mathieueveillard.com/blog/la-critique-est-facile-lart-est-difficile/https://www.mathieueveillard.com/blog/la-critique-est-facile-lart-est-difficile/A simple account from someone who had the audacity to try to book a train ticket via the SNCF Connect website.Wed, 05 Apr 2023 00:00:00 GMTRanthttps://www.mathieueveillard.com/blog/le-test-driven-development-un-outil-parmi-dautres/https://www.mathieueveillard.com/blog/le-test-driven-development-un-outil-parmi-dautres/While TDD is a wonderful tool, it is not suitable for all development projects, as it risks falling prey to the “law of the instrument.”Wed, 29 Mar 2023 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/pisseurs-de-code/https://www.mathieueveillard.com/blog/pisseurs-de-code/Let the people who use this expression sit down at the keyboard and show us what they can do…Wed, 22 Mar 2023 00:00:00 GMTRantWorkhttps://www.mathieueveillard.com/blog/la-methode-mikado/https://www.mathieueveillard.com/blog/la-methode-mikado/The Mikado Method involves mapping out the dependencies of the refactoring, then refactoring starting from the leaves of the tree thus established.Wed, 15 Mar 2023 00:00:00 GMTRefactoringCraftsmanshiphttps://www.mathieueveillard.com/blog/provoquer-le-changement/https://www.mathieueveillard.com/blog/provoquer-le-changement/Whatever your exact role (Lead Dev, Tech Lead, VP of Engineering, CTO…), be demanding but know how to be considerate of your team.Wed, 08 Mar 2023 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/emulation-de-typage-nominal-en-typescript/https://www.mathieueveillard.com/blog/emulation-de-typage-nominal-en-typescript/Structural typing is limiting when it comes to defensive programming. Fortunately, it is possible to emulate nominal typing (branding).Wed, 01 Mar 2023 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/vous-faites-erreur/https://www.mathieueveillard.com/blog/vous-faites-erreur/A distinction must be made between development errors—which are handled with exceptions—and user input errors.Wed, 15 Feb 2023 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/rest-in-peace/https://www.mathieueveillard.com/blog/rest-in-peace/Separating the IT function from the business units it serves is a fundamental mistake, because IT is viewed solely through the lens of its cost.Wed, 08 Feb 2023 00:00:00 GMTOrganizationhttps://www.mathieueveillard.com/blog/no-code-lexcel-des-temps-modernes/https://www.mathieueveillard.com/blog/no-code-lexcel-des-temps-modernes/No-code and low-code tools have their place, provided their use is properly managed to avoid unpleasant surprises (shadow IT).Wed, 01 Feb 2023 00:00:00 GMTOrganizationhttps://www.mathieueveillard.com/blog/reinventer-la-roue/https://www.mathieueveillard.com/blog/reinventer-la-roue/Reinvent your development tools: Jest, Redux, React, or even TypeScript. This exercise will take your skills to the next level.Wed, 11 Jan 2023 00:00:00 GMTLearningCoachinghttps://www.mathieueveillard.com/blog/portrait-de-developpeur-clement-cornen/https://www.mathieueveillard.com/blog/portrait-de-developpeur-clement-cornen/A portrait of Clément Cornen, a developer and, above all, a friend. Our values are very much aligned, both in development and in life.Wed, 04 Jan 2023 00:00:00 GMTInterviewCraftsmanshiphttps://www.mathieueveillard.com/blog/3-metaphores-du-code-informatique/https://www.mathieueveillard.com/blog/3-metaphores-du-code-informatique/Code is intangible. So, to make it more understandable, we use metaphors from the real world, particularly real estate.Wed, 28 Dec 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/architecture-hexagonale-trade-off/https://www.mathieueveillard.com/blog/architecture-hexagonale-trade-off/Hexagonal Architecture aims to isolate the application and the domain from the infrastructure. The trade-off is that the infrastructure knows the domain.Wed, 21 Dec 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/ddd-strategique-vs-ddd-tactique/https://www.mathieueveillard.com/blog/ddd-strategique-vs-ddd-tactique/First, focus on the system’s modularity at a large scale (strategic DDD). Tactical patterns are important, but they come later.Wed, 14 Dec 2022 00:00:00 GMTModularityCraftsmanshiphttps://www.mathieueveillard.com/blog/tdd-is-dead-long-live-testing/https://www.mathieueveillard.com/blog/tdd-is-dead-long-live-testing/A point-by-point rebuttal of the seminal article by David Heinemeier Hansson, a critic of Test-Driven Development.Wed, 07 Dec 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/devops-le-grand-malentendu/https://www.mathieueveillard.com/blog/devops-le-grand-malentendu/As it has become more widespread, the DevOps approach has strayed from its original spirit, sometimes to the point of being misinterpreted. Let’s set the record straight.Wed, 30 Nov 2022 00:00:00 GMTCraftsmanshipOrganizationhttps://www.mathieueveillard.com/blog/parce-que-la-forme-est-contraignante-l-idee-jaillit-plus-intense/https://www.mathieueveillard.com/blog/parce-que-la-forme-est-contraignante-l-idee-jaillit-plus-intense/Code katas are the perfect setting to experiment with new ways of working by imposing constraints. Example: coding using only the keyboard.Wed, 23 Nov 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/event-driven-architecture-ou-event-sourcing/https://www.mathieueveillard.com/blog/event-driven-architecture-ou-event-sourcing/EDA: a communication model that promotes the decoupling of contexts; ES: a coding model dedicated to traceability within a context.Wed, 16 Nov 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/le-meilleur-marche-est-le-plus-cher/https://www.mathieueveillard.com/blog/le-meilleur-marche-est-le-plus-cher/Developing quickly without mastery invariably leads to the accumulation of technical debt. Invest in it now—it will cost you less in the long run.Wed, 09 Nov 2022 00:00:00 GMTCEOhttps://www.mathieueveillard.com/blog/coach-a-temps-partiel/https://www.mathieueveillard.com/blog/coach-a-temps-partiel/Beyond the cost, bringing in a full-time coach can prove counterproductive, as your teams need time to process the changes.Wed, 26 Oct 2022 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/5-questions-a-antoine-sauvage-cto-dovrsea/https://www.mathieueveillard.com/blog/5-questions-a-antoine-sauvage-cto-dovrsea/Now, let’s hear from one of my clients, Ovrsea. Antoine, the CTO, explains how the idea to bring in coaching for his teams came about and what it has changed.Wed, 19 Oct 2022 00:00:00 GMTCoachingCraftsmanshipInterviewCEOhttps://www.mathieueveillard.com/blog/danger-zone/https://www.mathieueveillard.com/blog/danger-zone/As agility has become more widespread, it has been misused, becoming synonymous with micromanagement and absurd practices. Yet we need agility now more than ever.Wed, 12 Oct 2022 00:00:00 GMTCoachingCraftsmanshipAgile and Leanhttps://www.mathieueveillard.com/blog/descolarisation/https://www.mathieueveillard.com/blog/descolarisation/The goal of higher education should be to “de-school” students—that is, to prepare them for a VUCA world.Wed, 05 Oct 2022 00:00:00 GMTLearninghttps://www.mathieueveillard.com/blog/typage-statique/https://www.mathieueveillard.com/blog/typage-statique/I challenge anyone to prove to me that it’s more efficient to do without static typing when building a JavaScript application.Wed, 28 Sep 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/vos-premiers-pas-dans-lartisanat-logiciel/https://www.mathieueveillard.com/blog/vos-premiers-pas-dans-lartisanat-logiciel/Clean Code is a good starting point, followed by TDD and Functional Programming. Wait a bit before diving into DDD and refactoring!Wed, 21 Sep 2022 00:00:00 GMTCoachingCraftsmanshiphttps://www.mathieueveillard.com/blog/refactoring-la-technique-du-golden-master/https://www.mathieueveillard.com/blog/refactoring-la-technique-du-golden-master/The Golden Master method aims to prevent regressions during refactoring and relies on the prior creation of a set of functional logs.Wed, 14 Sep 2022 00:00:00 GMTRefactoringCraftsmanshiphttps://www.mathieueveillard.com/blog/les-architectures-restent-les-technos-s-envolent/https://www.mathieueveillard.com/blog/les-architectures-restent-les-technos-s-envolent/Technologies are fleeting: invest in mastering architectures, paradigms, and methodologies, which will serve you throughout your life.Wed, 07 Sep 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/i-love-kubernetes/https://www.mathieueveillard.com/blog/i-love-kubernetes/Technology is beautiful and fascinating, but it is not an end in itself. Information technology is there to solve problems in a pragmatic way.Wed, 31 Aug 2022 00:00:00 GMTRantCraftsmanshiphttps://www.mathieueveillard.com/blog/on-ne-fait-pas-boire-un-ane-qui-na-pas-soif/https://www.mathieueveillard.com/blog/on-ne-fait-pas-boire-un-ane-qui-na-pas-soif/Trying to support a company or an individual who doesn’t want to change is counterproductive. It’s better to rely on the corporate culture.Wed, 24 Aug 2022 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/faites-des-erreurs/https://www.mathieueveillard.com/blog/faites-des-erreurs/Error as a pedagogical principle: it is necessary for a deep understanding of problems and gives meaning to best practices.Wed, 20 Jul 2022 00:00:00 GMTCoachingLearninghttps://www.mathieueveillard.com/blog/refactoring/https://www.mathieueveillard.com/blog/refactoring/Refactoring comes with two challenges: avoiding regressions and overcoming tunnel vision. To help you: Golden Master, the Mikado Method, and the Strangler Fig pattern.Wed, 13 Jul 2022 00:00:00 GMTRefactoringCraftsmanshiphttps://www.mathieueveillard.com/blog/le-mur-de-la-dette/https://www.mathieueveillard.com/blog/le-mur-de-la-dette/Technical debt is dangerous because it accumulates silently, until the day the company hits a wall. CEOs, take the lead.Wed, 06 Jul 2022 00:00:00 GMTCraftsmanshipCEOhttps://www.mathieueveillard.com/blog/pourquoi-le-logiciel-coute-til-cher/https://www.mathieueveillard.com/blog/pourquoi-le-logiciel-coute-til-cher/Writing code isn’t that hard; evolving it is. Readability, testability, modularity: the three pillars of software craftsmanship.Wed, 29 Jun 2022 00:00:00 GMTCraftsmanshiphttps://www.mathieueveillard.com/blog/formation-vs-accompagnement/https://www.mathieueveillard.com/blog/formation-vs-accompagnement/Training is, at best, a spark. Without ongoing support, putting what you’ve learned into practice is often difficult.Wed, 22 Jun 2022 00:00:00 GMTCoachinghttps://www.mathieueveillard.com/blog/coach-technique-mon-metier-nexiste-pas/https://www.mathieueveillard.com/blog/coach-technique-mon-metier-nexiste-pas/When the organization is dysfunctional, you call in an agile coach. When the codebase stops evolving, you call in a code doctor: a technical coach.Wed, 15 Jun 2022 00:00:00 GMTCoaching