Custom web application development
Modern web applications for companies, teams and startups: from a tool that replaces Excel and paper, through platforms connecting several parties, to SaaS products with billing and applications with built-in AI. We do the whole job, from design and database to hosting and support, with the same team and technology behind our products duplo, Kartonko and Repsalio B2B.
What we build
Anything that opens in a browser and gets the job done: a SaaS product for the market, a system for one company, a client portal, a platform with several roles, an application that replaces paper records. The purpose is yours; this is what every project gets from us.
Design and user experience
An application that looks like a product, not an internal tool. Works on phone and desktop, fast and accessible.
Users, roles and teams
Sign-up, passwordless or two-factor login, multiple roles and permissions, teams and invitations.
Data and integrations
E-invoicing, banks, payments, transactional email, PDF documents, QR codes, import and export, external APIs.
Real time and notifications
Chat, notifications, reminders, scheduling and email campaigns, for when the application has to work while nobody is watching.
AI inside the application
When the application needs to understand text, images or documents, talk to users or do part of the work for them, we build in the Claude API. What the AI does depends on your business, not on a ready-made template.
Languages and markets
Multilingual applications, billing in several currencies, content adapted to the region.
Hosting, security and maintenance
Production in Europe, backups, monitoring, security updates and support after launch.
Technology
The same stack across all four of our products, proven in production with paying subscribers. Claude speeds up our development, and the Claude API goes into the applications we build.
Next.js
React
TypeScript
Tailwind CSS
PostgreSQL
Neon
MongoDB
Vercel
Resend
Pusher
Claude- Claude API
How we work
Step 1
Conversation and process review
We visit you or get on a call. We walk through how the work flows today and where time is lost.
Step 2
Scope and quote
We propose what makes sense to build first, with a clear price and deadline for that part. No hidden items.
Step 3
Development in steps
We deliver in pieces that can be used right away. You review and adjust direction while it's being built, not at the end.
Step 4
Launch and maintenance
Training for the people who use the application, hosting in Europe, updates and support when needed.
Client reference
MOJ ERP
MOJ ERP is a custom system the manufacturing company ATM Lazić uses for its whole workflow, from customer order to e-invoice and bookkeeping.
Our products as proof
Everything we offer companies we already do for ourselves: three products with paying subscribers, hosted in Europe and supported by us.