Lead Architect Ionic, Capacitor & Angular.
12+ years building, scaling, and rescuing mission-critical cross-platform mobile & web applications. Expert in Ionic, Capacitor 8, Cordova migrations, Angular, React & native iOS/Android bridges.
Organizations that trusted my expertise
From CAC 40 giants to fast-scaling tech companies, I intervene on mission-critical roadmaps.
ENGIE
Field technician mobile app with resilient offline-first synchronization
BPI Centre Pompidou
Interactive public cultural mobile application
Siteflow
Industrial SaaS & Capacitor mobile encapsulation
D4H Technologies
Emergency response and incident management software
Dalkia (EDF Group)
Energy diagnostic mobile tooling & field operations
Decathlon
Cross-platform UI components & mobile performance
Kozikaza
3D home design community platform & web app
Ouest-France Immo
High-traffic real estate portal & mobile web
AlloVoisins
Local services marketplace & real-time messaging
Dassault Systèmes
Complex frontend engineering & software integrations
Thales
Secure web architectures & defense-grade compliance
Surgical senior engineering for your critical challenges.
No theoretical overhead: clean code, battle-tested architectural patterns, and immediate delivery acceleration.
Lead Dev & Senior Staff Augmentation
Direct integration within your engineering team to unblock complex roadmaps, instill clean architecture patterns, and speed up delivery cycles.
Cross-Platform Mobile Architecture
Architecture and development of high-performance mobile apps using a unified web codebase encapsulated with custom native bridges.
Technical Audit & Performance Tuning
In-depth code and runtime analysis to eliminate performance bottlenecks, slash page load times, and secure your production web apps.
Fractional CTO & Tech Advisory
Strategic guidance for founders and innovation directors: technical scoping, stack selection, and senior engineering hiring.
Apps I designed, engineered, and scaled on the Stores.
Building and publishing consumer and utility apps provides first-hand mastery of store approval workflows, offline architectures, and UX conversion.
Semainier
Organize and plan your weekly tasks, meals, and activities at a glance.
Code Wifi
Generate and print stylized QR Codes to connect your guests instantly to your Wi-Fi.
Rentabilité
Fast calculation of gross and net profitability for your real estate and business investments.
Poker Tools
Complete poker tool suite: pot odds, hand equity, and ICM calculators.
Notchr
Remove notch and Dynamic Island from mobile screenshots for clean presentations.
Roundr
Add elegant, customizable rounded corners to your screenshots and visual assets.
Salaires
Easily convert and calculate gross-to-net salary (executive, non-executive, public sector, freelance).
Behind the scenes of high-impact missions.
Here is how I resolved major architectural roadblocks and delivered resilient systems.
Mission-critical field application with zero-network resilience
Enable technicians to inspect underground installations in complete network dead zones with flawless data synchronization upon reconnection.
Engineered an offline-first storage engine with embedded SQLite, optimistic outbox queuing, and deterministic CRDT conflict resolution.
B2B SaaS migration to Next.js App Router & 100/100 CWV
Legacy SaaS platform suffering from 4.5s load times and penalizing Core Web Vitals affecting organic search traffic.
Migrated to Next.js App Router with React Server Components, streaming SSR, and 68% client JS bundle reduction.
Custom biometric authentication & secure hardware storage plugin
Integrate hardware-grade biometric authentication and encrypted key storage in Apple Secure Enclave & Android KeyStore for a hybrid app.
Authored a custom Capacitor 8 plugin in pure Swift 6 and Kotlin with cryptographic hardware signing.
Modern, production-proven technologies.
A strictly curated toolchain engineered for performance, long-term maintainability, and resilience.
Frontend & Web
App Router, Server Components, SSR
Strict typing, Advanced Generics
Design systems, Responsive, A11y
Maintenance & legacy migrations
Mobile & Cross-Platform
Certified Ionic Developer Expert (IDE)
Native plugins, StoreKit 2, Widgets
Android 16 / Target SDK 36
SQLite, WatermelonDB, CRDT sync
Architecture & Backend
High-throughput APIs & microservices
Auth, Firestore, PostgreSQL, Edge Functions, Realtime
Query optimization, Caching
GitHub Actions, Appflow, Fastlane
Ionic Developer Expert (IDE) Certification
Global distinction awarded to leaders in the Capacitor & Ionic ecosystem for native bridge craftsmanship and high-performance cross-platform system architecture.
Freelance vs Agency: What is the right model for you?
As Founder & CTO of **Kerweb agency**, I also lead full turnkey digital projects (UX/UI design, native mobile engineering, App Store compliance, and 24/7 SLA maintenance).
Hire Me as Independent Consultant
Julien Kermarec • Advisory & Lead DevIdeal when you already have an engineering team or need immediate surgical senior reinforcement.
Entrust your project to Kerweb
Turnkey Web & Mobile AgencyIdeal if you need a multidisciplinary team (UI/UX designers, iOS & Android native engineers, QA) managed by me.
Let's discuss your next technical challenges.
I reply within 24 business hours. Briefly describe your challenges, current tech stack, and timeline.
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