Custom software development · Europe

We buildyour software —and operate our own.

MATTALNET is a team of senior software developers. We build complete systems — web application, backend, admin interface and native apps — shaped around how your company actually works.

Discuss your project in 30 minutes →See our work

Team Senior engineersCore stack .NET 8 / React / TSMobile iOS + Android (native)Scope End-to-endLocation Freiburg, DEEngagement New projects

Numbers from systems in production.

17systems in production

~100E2E tests per product

17languages shipped

100%source code & documentation handed over

Figures from software running live today — built and, in part, operated by us.

[ 01 ]

What we build.

Six kinds of systems we know how to deliver.

Custom SaaS platforms

Multi-tenant products with roles, billing and an admin area of their own.

Internal business systems

The software your operation runs on, shaped around your actual process.

Warehouse & logistics software

Stock, orders, shipping and telematics — in real time, in many languages.

Customer & partner portals

Self-service, quotes and document flow for people outside your company.

Mobile applications

Native iOS and Android where offline, camera, push and location matter.

AI-powered workflows

LLM and RAG inside production applications — with cost control and a human check.

[ 02 ]

Selected systems, live in production.

Every one of these products is running today. We built them and operate some of them ourselves — which is why we know how they behave under real load.

smartwms.one↗

SmartWMSWarehouse OS

Warehouse OS for small teams

The problem

Classic warehouse systems are built for large operations: heavy, expensive, overloaded. Small teams need real-time visibility and clear flows — without a six-month rollout.

What we built

Module-isolated architecture — features change without collateral damage
Real-time stock & events over SignalR
17 languages out of the box, IoT monitoring built in

Result

A warehouse operating system a small team can run themselves: real-time stock, orders and IoT monitoring in one platform, shipped in 17 languages.

Stack

.NET 8EF CorePostgreSQLSignalRReactRTK Query

View case study →

invocore.eu↗

InvocoreE-Invoicing SaaS

EU e-invoicing for the EN-16931 era

The problem

Mandatory e-invoicing turns an accounting detail into a regulatory risk: XRechnung, ZUGFeRD, EN-16931, reverse-charge and audit-proof archiving all have to line up — or the invoice is rejected and the audit fails.

What we built

XRechnung & ZUGFeRD from one source, checked against the official schema
Tax logic incl. reverse-charge (§13b) and small-business rules
Audit-proof archive with a verifiable chain of record

Result

A platform that generates, validates, sends and archives EN-16931-compliant invoices in an audit-proof way — including DATEV export and EU localisation. Correctness is provable, not asserted.

Stack

FastAPIPostgreSQLCeleryRedisReactMUI

View case study →

astrolingua.app↗

AstroLinguaAI Exam Prep

Pass the DTZ — on the first attempt

The problem

The DTZ (German integration exam) gates residency and citizenship. People preparing juggle books, YouTube and scattered PDFs — with no real exam simulation, no feedback and no explanation in their own language.

What we built

All four skills: listening, reading, writing, speaking
AI conversation partner with 6 Azure neural voices
Essay grading by photo or text, Leitner vocabulary

Result

A learning platform that realistically simulates the DTZ instead of just collecting material: 2,900+ words, grammar A1–B2, AI coaching and real exam tasks — free during beta.

Stack

Next.jsReactFastAPIPostgreSQLLLMAzure Speech

View case study →

More systems we shipped

nootee.com↗

NooteeAI Product

An AI agent that never sleeps

vindora.one↗

VinDoraMarketplace · Configurator

Configure windows, get quotes from vetted installers

sued-fenster.de↗

Süd-FensterLanding · Configurator

Made-to-measure windows — from survey to installation

adavatar.io↗

AdavatarAI Marketplace

AI avatar marketplace for video

famora.one↗

FamoraFamily Platform

Family organisation for the DACH region

onlimit.shop↗

OnLimitCommerce

E-commerce platform with native apps

clearcontract.io↗

ClearContractAI Fintech

AI financial audit for the DACH region

logixa.one↗

LOGIXALogistics · TMS

TMS & fleet management for forwarders

View all 17 projects →

[ 03 ]

Three commitments we keep measurable.

What German mechanical engineering takes for granted applies to our software too.

01 / 03

Reliability

Systems that hold under load

Architecture with clear failure boundaries and repeatable behaviour. The code stays maintainable two years from now — as the system grows or your team takes over.

02 / 03

Quality

Code your team can take over

Type-safe, tested and documented, following recurring architecture patterns and consistent conventions. You get a clean codebase with documentation and can carry on without us at any point.

03 / 03

On-time delivery

Shipped when promised

Fixed cuts into small, deliverable units. You see a running build every week, and delays surface while they can still be corrected.

[ 04 ]

How we build.

Three habits that decide whether a project lands on time — and what each one buys you.

Architecture

Modular and reusable

Self-contained feature modules with clear boundaries, plus proven building blocks from earlier systems. Less code to write means less to pay for and a working build in your hands sooner.

Test gate

Every feature against tests

Around 100 end-to-end tests per product run before anything ships. New features stop breaking old ones, so a release stays routine instead of becoming a risk.

Process

AI-assisted feature cycle

A disciplined cycle from feature to test, AI-assisted and human-reviewed. The speed sits in the process; the responsibility stays with us.

[ 05 ]

Software built around your business — not the other way around.

Standard systems force your processes into someone else's structure. We turn that around: frontend, backend and admin interface are built around your workflow — lean, secure and free of plugin ballast nobody maintains.

vindora.one↗

// Case example

vindora.one — configure windows, compare quotes

A fully custom system instead of a template site — three cleanly separated layers:

LandingNext.js · React · Tailwind
BackendFastAPI · PostgreSQL · Celery
AdminReact · Material UI · RTK Query

The client edits everything themselves — sections, copy, photos, prices — quickly and comfortably, entirely without us.

View case study →

Not our field

/ Pure visual design without technical substance
/ Throwaway prototypes without tests or maintainability
/ Hourly billing without a deliverable result

Where we deliver

+ Complex architecture and demanding integrations
+ Multi-tenant SaaS and micro-frontend systems
+ Native mobile apps: iOS (Swift) and Android (Kotlin)
+ AI and LLM integration in production applications
+ Product development from architecture to release

[ 06 ]

Technologies we genuinely master.

Few stacks, but deep. That keeps the quality where your project needs it.

Frontend

React / TypeScriptNext.jsViteMUI / TailwindRTK Query / ReduxMicro-Frontends

Backend

.NET 8 / C#Python / FastAPINode.jsEF CoreSignalR / RealtimeWebSocket

Mobile

Swift / iOSKotlin / AndroidSwiftUI / Compose

Data · Infra · Method

PostgreSQL / PostGISRedis / CeleryDockerVertical Slice ArchitectureMulti-tenant SaaSLLM Integrationi18n / 17 languagesPlaywright / E2E

We adopt new technology when it solves a problem — not because it is new.

Next step

Tell us about your project.

30 minutes with a developer instead of a salesperson. We listen, assess feasibility, effort and timeline, and tell you honestly whether we are the right team.

Book a first call →