Aymeric

@aymeric.fyi

Engineering Management & Technology • Engineering Manager @ Mercari in 🇯🇵

#LDX3 The shadow culture: Why engineering principles fail under load by Manogna Machiraju We all want to build things fast with the right level of quality. The reality: the code is archaic, pipelines are broken, security is an afterthought. Engineering is always catching up.

#LDX3 AI in the trenches: Real-world wins without breaking things by Yiğit Darçın Deja Vu vs. Vuja De - the feeling that you have never seen it before. MIT study: the "GenAI Divide" - 95% of AI pilots fail to generate ROI, while a successful 5% utilize a "Vuja de" approach to rethink workflows.

#LDX3 AI killed the coding interviews. Here’s what Meta built instead by Danit Nativ Navon What broke? * Candidates used AI tools during interviews * Evaluations and ladders didn’t evolve * Leaders had no idea how to lead in this new context

#LDX3 Technology advances; history repeats itself by Zoe Cunningham A talk emphasizing the need to keep focusing on humans when everything is changing 🥰 The rate of change is increasing. The current message around the tech industry is impacting managers drastically: less managers, more IC work.

#LDX3 How to grow your engineers into great leaders? by Charles Duncan Jr. Your best engineer may not be your best managerial candidate The IC and manager jobs are different, require different skillset

#LDX3 Engineering at scale: Why developer experience is your competitive advantage by Dr Nicole Forsgren Teams "move" at 10x speed but the system moves at 1x The speed/friction mismatch * 15 minute builds * Manual approvals * Unclear deployment criteria * No documentation of decisions

#LDX3 What will AI-accelerated engineering teams actually look like? Panel with Luke Marsden, Hannah Foxwell, Yenny Cheung, Liz Fong-Jones What practices that predate AI help us move faster now? Documentation, comments, tests, small PRs Spec driven dev in all parts of SDLC: from PRD to tests

#LDX3 Building resilient engineering teams when failure is the default by King-Immanuel Edoh In Nigeria, infrastructure is highly unreliable, starting with the power grid. This forces good engineering practices to be the default Fantastic and lively talk by King-Immanuel.

#LDX3 What does a CTO even do? by Dee Kitchen 1. Do we have the right people? 2. Do we have the right technology? 3. Do we have the right product vision? 4. Do we have the right balance between innovation and liability 5. Do we have the right enablement and sales motion?

A spider chart of the 5 key competencies a CTO needs to cover: People, Tech, Product, Sales and Risk.

#LDX3 Up and down the management track: Equalising your leadership style across the pressure of scale by Karen Lee Lessons from Karen who had an went up and down the management track, starting as engineering, growing to EM, MoM and Director, back down to MoM, EM and back up, twice.

#LDX3 Moving Accessibility from debt to done at giffgaff by Abi Harrison-Nye Accessibility represents an 8T$ opportunity globally, that’s the buying power of people with any disability. Making the product right, accessible, from the start, does not cost more or add time to a project.

giffgaff.com

#LDX3 The mechanics of scaling: Why delivery slows as you grow and what do to about it by Maryia Tarpachova As the company grows, features keep being added to create more growth, and pace starts to slow down A deep dive revealed specific teams were impact more than others, mostly core teams

#LDX3 Quantifying tech debt to modernize critical systems by Ejber Ozkan Tech debt negatively impacts productivity Image from Tushar Sharma in Four Strategies for Managing Technical Debt Tech debt is net asset to build features for the business and becomes a liability when it reaches a threshold

The vicious cycle of technical debt:
Pressure to increase productivity leads to high technical debt, leads to low moral and motivation and to low code quality, which leads to lower productivity, which leads back to presurre to increase productivity.

I’m coming from Tokyo to attend LeadDev LDX3 in London. (1/2) I’m particularly interested in how organizations are transitioning into AI-native organization, as we are in the middle of that process at Mercari. Let’s meet to discuss these topics or if you want to learn about Japan’s tech scene.

A LeadDev LDX3 Conference poster with a purple background and the following text:
LDX3
London
June 2 and 3, 2026
The festival for modern engineering leadership

I tried Claude Design to design a new feature in my app. It speeds up UI prototyping over vibe coding prototypes. The prototypes are interactive and it’s possible to run them side-by-side. The hand-off to Claude Code is janky but it’s quite new so it’ll improve. Check the post for details.

Hands-on With Claude Design

Anthropic just launched Claude Design, a new research-preview product for generating interactive prototypes, slide decks, and more. I took it for a spin by designing a new analytics screen for my habi...

aymeric.fyi

I released my first mobile app on iOS and Android. There is such a contrast between how fast building with AI is, and how slow the mobile app release process is. I wrote about the whole experience in this post.

Building OnTrack Mobile Apps With AI: Coding Fast, Releasing Slow

In this post, I share my experience building a cross-platform habit tracker mobile app using AI coding tools, highlighting the stark contrast between lightning-fast development and the surprisingly sl...

aymeric.fyi

Google is hot right now, back to back days announcing big things 😳 Sunday: Universal Commerce Protocol Monday: Apple picked Gemini for Siri

A very easy to understand review of the paper Too Big to Think: Capacity, Memorization, and Generalization in Pre-Trained Transformers,". Large models simply memorize the training data. Smaller models learn the rule because they don't have enough "brain space" to memorize every individual answer.

Why I care more about your SLM than your LLM

A review of the paper Too Big to Think: Capacity, Memorization, and Generalization in Pre-Trained Transformers," (Barron & White, 2025)

statisticianinstilettos.com

Ben Thompson argues that while AI is obviously in a bubble, it will create long term benefits in the form of investments in chip fabs in the U.S. and power plants. This is similar to how we got dark fiber and train tracks as infrastructure out of the internet and railway bubbles.

The Benefits of Bubbles

We are in an AI Bubble: the big question is if this bubble will be worth it for the physical infrastructure and coordinated innovation that result?

stratechery.com

What happens to a driving Waymo when AWS us-east-1 goes down? 😅 Is everything processed locally? It’s an Alphabet company, so if something is remote, I’d expect it to be on GCP or Google internal platforms, but with external dependencies, isn’t every product 6 degrees of separation from us-east-1?