Passion, not just work
Software development has never been a 9-to-5 job for us. We dig deep into problems, prototype relentlessly, and care about every detail — from API design to deployment.
Mindoo GmbH · Karlsruhe, Germany
We love what we do.
We think outside the box.
We explore the limits of technology.
Mindoo is a software engineering company founded in 2008 by Karsten Lehmann and Tammo Riedinger. Both founders have been professional software engineers since 2000, building graphical desktop applications, web platforms, collaborative tools, and data-intensive business systems.
Over the years our technology stack has evolved continuously — from Java Swing and HCL Notes/Domino through Spring Boot, React, Vue.js, and MongoDB to Kotlin, end-to-end encryption, and LLM-powered development tooling. What has stayed the same: a passion for pushing technology forward and delivering software that actually works.
What drives us
Privacy & data ownership
We believe users should control their own data. That conviction shaped our newest product MindooDB — an end-to-end encrypted, local-first sync database where neither the server nor the operator can access the content.
Rapid technology adoption
We embrace new platforms early. From being an IBM Design Partner testing pre-beta Notes/Domino releases to adopting LLMs for code generation, RAG pipelines, and AI-assisted architecture work — we stay at the frontier.
What we do
Architecture & engineering
We design and implement modern web and backend systems. Our current stack includes Spring Boot, React, Vue.js, Node.js with TypeScript, Kotlin, MongoDB, and PostgreSQL. We act as hands-on architects who write production code, not just diagrams.
Migration & modernization
We help organizations migrate from legacy application stacks to maintainable, modern systems. We have deep experience transforming monolithic applications into service-oriented architectures while preserving business logic and data integrity.
Product development
We build products from concept to production. Our latest is MindooDB, an open-source end-to-end encrypted sync database (Apache 2.0). Previous products include MindPlan (collaborative mind mapping & project management) and Mindoo CMS.
AI & LLM integration
We integrate large language models into development workflows and enterprise applications. From RAG pipelines that augment LLM prompts with structured business data to AI-assisted code generation tooling — we bring practical AI into real projects.
Selected project history
Over nearly two decades we have delivered solutions across a wide range of industries and technology stacks. Here are some highlights.
Haven
Haven is a calm, collaborative workspace where your team works with notes, files, apps, and data - encrypted by default and installable on any device. It runs on MindooDB, an open-source, local-first sync database you can run on your own servers, in your own jurisdiction; the server only ever sees ciphertext. Real data sovereignty, without giving up real-time collaboration. mindoodb.com
MindooDB
An end-to-end encrypted local-first sync database for desktop and mobile devices. All data stays on the user's devices and is synchronized via server or peer-to-peer. Every change is digitally signed. Available under the Apache 2.0 license. mindoodb.com/mindoodb
E-commerce & consumer goods platform
Architecture and ongoing development for a large consumer goods company's online shop, event booking / product tasting applications and other internal enterprise applications. Technologies: Spring Boot, Vue.js, React, MongoDB, PostgreSQL, Google Datastore, HCL Notes/Domino.
Domino JNA & Domino JNX
Domino JNA is our open-source Java library providing cross-platform access to the HCL Domino C API via JNA — exposing functionality far beyond the standard Java API. Together with HCL's Innovation Labs and Jesse Gallagher, we then built Domino JNX, the modern Java API that powers the HCL Domino REST API.
Mindoo CMS
A Domino-powered web content management system with live editing, responsive templating, full history, and approval workflows. Used by municipal websites and a regional print shop's collaborative article authoring platform serving 3,000+ users.
Local-first mobile document client
An local-first mobile document client framework with a configurable web UI, diff-based synchronization, and automatic database migrations for iOS and Android.
Weilgut eOffice
Architecture and development of eOffice, an OSGi-based CRM system for the HCL Notes/Domino platform. Built with Java on the backend and Sencha ExtJS on the frontend, eOffice provides contact management, activity tracking, sales pipeline, and document workflows for professional services firms — tightly integrated into the Domino collaboration environment.
KPI dashboard for global car manufacturer
A responsive web-based management dashboard that transforms high-volume operational data into configurable KPI views and rich visualizations, designed as a clean, executive-ready interface for fast weekly decision-making.
Field research platform for global energy-drink brand
A mobile-ready web application for capturing on-the-go market-research data, feeding a searchable, multi-country database of competitor products and variants for fast field-level insight.
Succession planning for automotive management
Project support and quality assurance for the rollout of a succession planning system targeting management positions at a major automotive group.
Intranet CMS for automotive group
Design and implementation of an HCL Notes/Domino-based web content management system powering the corporate intranet of a major automotive group.
MindPlan
A collaborative mind mapping and project management desktop application (Java / Swing), developed in partnership with Haus Weilgut GmbH. Awarded the IBM Lotus Award TCO (2008) and twice won the "Innovationspreis der Initiative Mittelstand" in the knowledge management category (2005, 2007).
Aviation process optimization
Tools for process optimization in the aviation industry, including custom workflow and data processing solutions for ground handling and operations teams.
Technology we work with
We pick the right tools for each project. Our current and recent technology stack includes:
Frontend
React, Vue.js, TypeScript, Astro, HTML5, CSS
Backend
Spring Boot (Java & Kotlin), Node.js with TypeScript, HCL Domino
Data & storage
MongoDB, PostgreSQL, SQLite, Google Datastore, Automerge CRDTs
AI & ML
OpenAI, Google AI Studio, RAG pipelines, LLM-powered code generation
Infrastructure
Cloudflare, Docker, CI/CD, GitHub Actions
Security
End-to-end encryption, digital signatures, append-only audit logs
Latest from the blog
Technical articles, project updates, and conference talks — since 2009.
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Mindoo TeamEdit update - collaborative Word/.docx editing on MindooDB Haven
25.05.2026
Mindoo TeamEdit gains a Word/.docx editing mode alongside the existing collaborative Markdown editor. Two people can now open the same .docx file in two TeamEdit instances, type into the same paragraph, drop in images, reshape a table, accept tracked changes, leave threaded comments - and watch the merged result appear on both screens through MindooDB's Automerge sync, with only the actually changed spans on the wire. TeamEdit also handles multiple documents open at once - a Window menu lists every open Markdown brief and Word memo and lets you flip between them. Under the hood the document is mapped to Automerge's rich text format (formatting spans plus block markers) on top of the EigenPal docx-editor we picked after evaluating SyncFusion and Apryse - chosen for its Apache 2.0 license, OOXML round-trip fidelity, and ProseMirror foundation that lets us plug in MindooDB's collaborative storage cleanly.
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Mindoo TeamGrid update - virtual view sheets, 280 Excel formulas, charts and templates in MindooDB Haven
21.05.2026
Four days after the initial release we are shipping a big round of updates to Mindoo TeamGrid, the open source collaborative spreadsheet for MindooDB Haven. The headline feature is Virtual View Sheets - pick any virtual view configured in Haven (including views that combine your private data with work data and with data from a partner company's tenant) and drop it into your workbook as a normal worksheet that Excel formulas, charts and XLSX export can read. Alongside it: a much larger formula engine with 280 Excel-compatible functions courtesy of fast-formula-parser, the four chart types Excel users actually use day to day (Column, Bar, Line, Pie), spreadsheet templates with File / New from template..., hidden rows and columns that survive an Excel round trip, automatic cell type detection from typed content, and a selection and keyboard model much closer to what people expect from Excel. And all of it still merges across two laptops, two devices, and four tabs the same way it did on day one.
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How MindooDB stores attachments - encrypted chunks, append-only history, and on-the-fly MP4 streaming in Haven
19.05.2026
Attachments in MindooDB are not stored as one blob hanging off a document. Each file is a chain of small encrypted chunks (256 KB by default, encrypted with the document's own key), and each chunk points back at its predecessor. The document only references the *last* chunk - which turns growing a file into appending one chunk, makes earlier document revisions automatically see only the bytes that existed then, and reduces moving or duplicating a large attachment between documents to copying a tiny JSON entry. Chunks are deduplicated by a hash of their encrypted bytes, so the same file inside one MindooDB database occupies storage once and syncs once. On top of all that, Haven streams long media attachments straight from those decrypted chunks - and for older MP4 files that browsers refuse to stream, Haven rebuilds them on the fly into a streamable shape with a lazy-loaded mp4box.js pipeline.
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Document scanning in MindooDB Haven - turn any paper into an attachment with one button
18.05.2026
Hold a phone over a piece of paper, press one button, and it lands inside the document you are working on - cropped, deskewed, rotated, and saved as a clean PDF or image. The new Scan document feature in MindooDB Haven is built on a custom, size-optimized OpenCV WebAssembly build that finds the page corners automatically and lets you nudge them by hand. Pick A4, Letter, a square or just keep the original aspect ratio, rotate in 90-degree steps, then Add to document - where it becomes a regular MindooDoc attachment - or, on iOS, iPadOS and desktop Safari, press Share file to hand the scan straight to the system Share Sheet without any upload at all. Available out of the box to every MindooDB app via the MindooDB App SDK.
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Application time travel in MindooDB Haven - launch any app as it was at any moment in time
17.05.2026
MindooDB Haven application registrations now carry an optional time travel date. Set it, launch the app, and every mapped database, every virtual view, every document and every attachment is served as it would have looked at that exact moment - read-only, all the way down to the historical attachment bytes. Duplicate the registration, pin two copies to two different dates, switch the runtime mode to 'Open in new window', and compare last sprint's plan against today's plan in two browser windows side by side. Audit, retrospective, regression debugging, and historical reporting - rendered in the real application UI, backed by MindooDB's signed, blockchain-style change history. Available out of the box for every MindooDB app running in Haven.