--- title: "Build Internal Tools | Artus Engineering" description: "Replace spreadsheets without Retool lock-in: GDPR-compliant internal tools on German servers. From €14k, senior team, the code is yours." canonical_url: "https://artus-engineering.de/en/services/internal-tools" md_url: "https://artus-engineering.de/en/services/internal-tools.md" last_updated: "2026-09-11T14:47:09.931Z" lang: en --- # Replace Spreadsheets — Without Retool Lock-in *Internal Tools* When spreadsheets buckle, SaaS gets more expensive, and nobody understands the macros anymore: we build internal tools that scale, stay auditable, and run on servers in Germany. Internal tools from €14k · MVP in 8–12 weeks ## Does This Sound Familiar? Heads of operations and IT come to us when the spreadsheet becomes a risk — not out of curiosity. ### Excel as a De Facto Database Past roughly 20,000 rows it slows to a crawl. Simultaneous edits create version chaos. For compliance and audits that is not a viable foundation. ### US SaaS Gets Expensive at Renewal Retool, Airtable, Notion: per-seat costs climb and external-user rules tighten. With 30 internal and 200 external users that quickly adds up to €15k–25k a year — without data sovereignty. ### Key-Person Risk One person maintains the Access file, knows the macros, holds the process together. When that person leaves, operations stop. ### No-Code Hits Its Limits Notion caps out at 20,000 records. As soon as you need relational logic, fine-grained permissions, and audit logs, the tool no longer fits. ## Why Artus Engineering ### GDPR + German Hosting + Green Power No Cloud Act, no third-country transfers. Hosting in Germany, a data processing agreement, and documented technical and organizational measures — explained in one sentence, not buried in a footnote. ### You Talk to the People Who Build It Two senior founders on the project. No account manager layer, no junior who first needs your business explained to them. ### Code and Docs Belong to You Git repo from day one, open stack (Next.js, TypeScript, Postgres). No vendor lock-in — neither with us nor with a US provider. ## Substance Instead of Marketing Fluff ### Before and After Instead of Buzzwords 12 spreadsheets, 47 macros → one Postgres schema, three roles, an audit log. That is how we document migrations — not with “end-to-end digital transformation.” **12 spreadsheets → 1 schema** ### A Permission Matrix Excel Cannot Do Role × data area × read/write — fine-grained, traceable, auditable. Exactly what your works council and data protection officer want to see. ### Three-Year TCO: Retool vs. Building Your Own With 30 internal users and growing external access, building your own often pays off from year two — maintenance included, with full control over your data. ## Retool vs. Your Own Tool — An Honest Comparison Example: 30 internal users, moderate complexity, three-year view. | | Retool (cloud) | Your own tool (Artus) | | --- | --- | --- | | Data sovereignty (DE/EU) | Limited (US cloud) | Complete (German hosting) | | Per-seat costs scale | Yes, rising | No — fixed maintenance | | Fine-grained permissions | Limited | Fully custom | | Audit log & compliance | Enterprise plan required | Standard | | Customizable without limits | Within the platform | Unlimited | | TCO over three years | approx. €45k–75k | approx. €35k–55k incl. maintenance | ## What Week One Looks Like ### Day 1: Kickoff and Process Discovery We map the process as it is — not the wish list from the spec document. ### Day 3: Domain Model and Data Structure Which entities, relationships, and roles does the system actually need? ### Day 5: Clickable Prototype First screens to try out — feedback from power users, not just from the CEO. ### Day 7: First Data Migration Spreadsheet data in Postgres — you see real numbers, not mockups. ## What You Hold in Your Hands When the Project Ends - Git repository with full access from day one - Architecture and operations documentation (Markdown) - Deployment scripts and runbook - Data processing agreement and record of processing activities - Role and permission model ## Realistic Ballparks ### Compact tool: €14k–35k A single process, few roles, no ERP integration ### Tool with integrations: €35k–84k ERP/DATEV integration, auth, workflows, multi-tenancy ### Platform: from €105k Several modules, complex permissions, long-term operations Maintenance typically 15–20% per year. Hosting on German servers from about €38 per month. ## Frequently Asked Questions ### Why not simply use Retool, Airtable, or Notion? For quick prototypes they often make sense. As soon as data sovereignty, scale, permissions, and compliance matter, no-code tools hit their limits — and per-seat costs grow with every user. ### Who maintains the tool two years from now? We do, under a contractually fixed maintenance scope with a clear SLA — or you take over using our handover documentation. The code is yours and the stack is standard. ### Could we not just use Power Apps? For simple forms, yes. As soon as relational data, audit logs, and GDPR-compliant hosting matter, Power Apps quickly gets expensive and inflexible. ### How quickly do we see results? First clickable prototype in week one. An MVP with real data typically in 8–12 weeks, depending on complexity and the number of integrations. ## Related Services - [Process Automation](https://artus-engineering.de/en/services/process-automation.md) - [Web Applications](https://artus-engineering.de/en/services/web-applications.md) - [Custom Software](https://artus-engineering.de/en/services/custom-software.md) ## Next Step [Start a project](https://artus-engineering.de/en/contact.md) ## Sitemap Complete overview of every page: [Sitemap](https://artus-engineering.de/en/sitemap.md)