Architecture that won't hold
Stack and architecture picked by AI, never validated: database, hosting, code structure, the foundations in short. You accept because it works. The day you realize it's the wrong fit, it's too late to turn back.
I make production‑ready the apps you build with AI.
For founders and domain experts shipping with Cursor, Claude Code, Lovable, Bolt, and sensing something's about to break in prod.
01 / The reality
You vibe-code your app. It moves fast. Not for long.
From the audits I run, apps built with AI hit an invisible wall between 50 and 500 users. Six fragilities show up almost every time:
DIY security
API keys in plaintext, homemade auth, secrets in the codebase: in other words, your house keys left under the doormat. One known vulnerability and everything is exposed.
Sluggish performance
Heavy code, cascading queries, blocking loads. The app crawls where it should shine.
GDPR never reviewed
Personal data flowing freely, implicit consent, sub-processors outside the EU. One audit and it's over.
No tests in place
You fix one bug, you ship three new ones. Without automated tests, every deploy is a roulette.
Hand-rolled deployments
No automated checks before going live, no test environment, no way to roll back. Every release is done by hand, fragile, and you just hope it holds.
02 / The answer
This is exactly where I come in.
“I start from what you've already built, I solidify it, and you keep building on top, but on foundations that hold. You focus on what you do best, I take care of what needs senior expertise.”
Step 01
Audit
Full read of the code, schema, and infrastructure. Mapping of risks across security, performance, GDPR, costs.
Step 02
Solidify
We fix what's critical, harden authentication, structure the architecture, wire up monitoring. Without breaking your flow.
Step 03
Ship
Production deployment with you, monitoring connected, documentation ready. You leave self-sufficient with clean foundations.
03 / Working together
Four offer families.
Audit of your app
Diagnostic Production-ReadyAn honest overview of what holds, what breaks, and what needs to happen before you really go to production.
- Audit: code, architecture, security, GDPR, API costs
- Written report 15-25 pages + 1h debrief
- Delivered in 2 to 3 days
Production deployment
Foundation BuildFrom your vibe-coded prototype to a production product: consolidated code, suitable hosting, hardened security, and the autonomy to keep evolving on your own.
- Site finalisation guidance + existing code audit
- Hosting advice + configuration + deployment
- Security hardening and GDPR compliance
- Vibe coding autonomy (Git + Claude Code installed)
- 14 days of post-delivery bug fixing
Embedded support
Sparring (coding alongside you) · Embedded Fractional CTOI code the foundations (architecture, backend, security) while you keep building the surface. Four intensities, depending on what your project needs.
Light
Standard
Intensive
Full
Offer D · Training
Trainings & workshops
Coaching & WorkshopsTo level up on your own, with your team, or in a cohort: from a quick assist to a structured program.
See formats- 1:1 Coaching · 2-3h
- Workshop “Building clean with AI”
- Team training
- Cohort program · 8 weeks
04 / The method
The Abecedia standard.
A quality bar I hold end to end, and the right expertise brought in when your project needs it. That's what makes the difference between a prototype that runs and an app you can entrust to real users.
Production-ready, continuously
Throughout the project, I hold the bar: code and architecture, security, tests, versioning, deployments, environments. No technical debt piling up behind your back.
Code reviewTests & CI/CDSecurity & GDPR
Independent validation, when needed
Based on project sensitivity, the code and technical choices can go through an independent validation, carried out by a senior backend engineer. An expert eye on top of mine.
External senior backendSensitive projectsAt any stage
Web design & UX, when needed
When looks and user experience matter as much as the tech: visual identity, web design, design system, UX audit, carried out by a web designer, an art director or a UX designer.
Visual identityDesign systemUX audit
05 / Who it's for
Four profiles I work with.
Solo or duo non-tech founders
You have an MVP running. Now it needs to be reliable, fast, defensible.
Post-MVP · growingDomain experts who build
Consultants, coaches, SMBs. You know your craft better than anyone, and you're finally building the tool you always wished you had.
Consultants · coaches · SMBsScale-up teams
Scale-ups that need senior tech eyes without hiring a CTO. To unblock, decide, secure.
Scale-ups · growingDesigners & PMs who build
You build your own internal tools with AI. I help you cross the gap between "it works" and "we can rely on it".
Internal tools · production usage
06 / About
Pierre Haegeli26 years in web development.
“I've spent my career coding, shipping, debugging in production. Today I help AI builders do the same, but in half the time.”
Senior Production Engineer + Embedded Fractional CTO. Co-founder of Docunify (B2B SaaS, 5 developers managed, FEDIL Innovation Start-up Award 2018, sold). 20 years specialized in senior frontend: React, Next.js, TypeScript.
26 years coding for real users. Tools change, the traps stay the same. My job: spare you the ones AI doesn't avoid yet. Rare posture: hands-on senior engineer and approachable, pedagogical coach. Based between Belgium and Luxembourg, I work in FR/EN across BE · LU · FR · UK · USA · Canada. 100% remote.
ex-DocunifyFEDIL Award 2018European InstitutionsArcelorMittalPOST Group
07 / Work
Products in production.
Vibe-coded prototypes turned into solid, secure products ready to grow. From backend to mobile, from architecture to deployment.
Long-term engagement · confidential client
MGM Garage Management
A team had built their garage management software with AI: working in a demo, but not ready to onboard real paying customers.
- Full architecture: web app, admin back office and mobile app
- Modernized interface, secured payments and customer data
- Automated deployments, in minutes
A complete, reliable product in production, and a team that became autonomous.
Engagement · Embedded Fractional CTOVisit the site
Long-term engagement · confidential client
Keep Focus Construction Platform
A software for the construction sector, functional but fragile and risky to evolve.
- Consolidated and secured technical foundations
- Fully rebuilt interface (web + 42-screen mobile app, in 6 languages)
- Safeguards to avoid nasty surprises in production
A solid, multilingual app, ready to grow with confidence.
Engagement + Production launchVisit the site
Personal project · end to end with AI
Grimzoo: Your memory, immortalized
An app that turns your memories into an intelligent companion able to tell your life story.
- Designed, developed and shipped entirely on my own
- Artificial intelligence, security and data privacy
- From idea to live product
Concrete proof of what I can deliver alone, end to end.
Full buildVisit the site
08 / Questions
The questions people ask me.
01What is an AI Builder Coach?
Someone who's been coding long enough to spot the traps AI tools don't avoid on their own: DIY auth, poorly modeled data, performance collapsing, GDPR ignored. Operationally, the word "coach" is misleading: on most engagements (Standard and Intensive modes), I'm primarily a Senior Production Engineer who codes the foundations destined for production, while you keep building on top.
02How does a Sparring work?
We pick an intensity together: Light (80% coach / 20% hands-on), Standard (50/50), or Intensive (30% coach / 70% hands-on). We set up a shared channel (Slack or equivalent), schedule regular video calls, and pair-code on hard points. You stay in control of your product, I code the foundations in parallel. Minimum 3-month engagement, renewable, 30-day notice.
03How is pricing calculated?
No public rate card: every project has its own number. We talk about it openly on the first call: you explain your context, I give you an honest estimate and a transparent framework before any commitment. No opaque package, no surprise.
04Why not just hire a senior dev directly?
At your stage, a senior is expensive, takes 3-6 months to recruit, and is a risk if your product isn't stable yet. With me, you've got someone within days, on 3-month renewable terms, no payroll, and you can adjust intensity over time. The goal is precisely to make you self-sufficient, not to keep you dependent. The day you can afford an in-house CTO, I hand off cleanly.
05Is my data secure?
NDA from the first call if needed. Read-only access to code and infrastructure, never to production data unless explicitly requested. And we discuss GDPR early: it's rarely the hardest part, but almost always neglected. Based on project sensitivity, an independent security review by an external senior backend engineer is done before going to production (Abecedia standard).
06Do you work internationally?
Yes. Based between Belgium and Luxembourg, I work in French and English, across European and North American time zones (Belgium, Luxembourg, France, UK, USA, Canada). 100% remote: video calls, written, code review, everything remote.
07How does the first call go?
30 minutes over video. You tell me about your project, what's blocking you, what worries you. I tell you frankly what I see, what's urgent, what can wait. No commitment, and even if we don't end up working together you leave with clear directions.
Let's go
You're building your thing.
That “what if it scales?” wall is coming. Let's talk. 30 minutes, no commitment, and you leave with a clear direction.
09 / Contact
Drop me a few lines.
I reply within 24 hours. We schedule 30 minutes over video, no commitment, and you leave with a first diagnostic.