Services
Web Application Development
Applications, not brochure sites: software where users log in, data changes, and correctness matters more than the animation on the hero section.
Brussels, Belgium · Senior-led delivery
A marketing website and a web application share a browser and almost nothing else. An application has state, permissions, concurrent users, validation rules, and consequences when it gets something wrong. The Weekly Dev builds the second kind: React and Next.js on the front end, typed APIs and PostgreSQL behind them, with the boundary between server and client drawn deliberately rather than by accident.
When this applies
- A website builder or page-builder plugin has hit its ceiling and the workarounds are now the system.
- The front end is fast to demo but slow in production once real data volumes arrive.
- Types stop at the network boundary, so every API change becomes a runtime surprise.
- The application works, but nobody is confident changing it.
What you get
- A React and Next.js application with server and client boundaries chosen for performance, not habit
- End-to-end type safety from database schema through the API to the interface
- Server-rendered pages where content should be indexable and fast on first load
- Accessible interfaces: keyboard navigation, focus states, semantic structure, and sensible contrast
- Automated deployment with preview environments per change
- Performance budget and Core Web Vitals measured against real page loads
How it runs
Assessment
We establish what the application must do, who uses it, and where the current implementation is holding you back.
Architecture
Rendering strategy, data access, and state boundaries are set up front. Getting these right is most of the performance work.
Build
Features ship in vertical slices: database, API, and interface together, so each one is genuinely finished.
Hardening
Accessibility, performance, and error handling are verified before launch rather than logged as follow-up work.
Questions
- What is the difference between a website and a web application?
- A website mainly presents content. An application maintains state on behalf of a user: accounts, permissions, records that change over time, which makes data modelling, authorisation, and error handling the bulk of the work.
- Can you work with an existing design or design system?
- Yes. Working from an existing Figma file or component library is common, and is usually faster than starting the interface from scratch.
- Do you take over applications built by someone else?
- Yes, starting with a codebase audit so both sides understand the actual state of the system before any commitment is made.
From the Publication
Writing from the studio on the technologies behind this work.
Understanding React Server Components From First Principles
Vassilios Zalimidis · February 25, 2026
Performance Debugging in Production: A Practical Guide
Vassilios Zalimidis · February 22, 2026
Implementing Authentication in Next.js 14 with Auth.js: A Step-by-Step Guide
Vassilios Zalimidis · August 22, 2024
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Start a Project
Have a project that needs web applications?
Send a short brief and you get a straight answer on feasibility, approach, and whether this is the right engagement, from the developer who would build it.