Service
Internal business tools
Not every task needs a large IT project. Often a small, understandable tool that maps one recurring flow is enough.
The problem
What I usually find: an Excel macro running in accounting. A second Excel doing almost the same thing in HR but slightly different. An Access database in sales, built by a former employee. Three small PHP scripts from 2017 that nobody understands. Seven half-baked tools in total, each with its own logic, data model, and lifecycle.
Nobody would build these seven tools that way today. But throwing them away also costs effort. What helps: consolidate gradually, lift the most important 2-3 onto a clean base, let the rest sunset with documentation.
The solution
Tool choice depends on the use case, not on hype. If it stays in the Office world with 5-15 users: Excel-VBA or Access. If multiple departments touch it or web access is needed: a lean FastAPI or Flask app with a clear JSON API, optionally a simple web front end.
Data lives where it belongs: Excel/SQLite for small tools, SQL Server or PostgreSQL for larger. Never two sources of truth without a clear sync concept. Authentication via what is already there (Windows auth in Access, OAuth or simple Basic Auth for web). Logging is mandatory, not optional.
Deliverables: the tool in Git, README with setup and maintenance conventions, deployment guide for your target environment, optional 60 min live walkthrough. For larger tools a backup and recovery strategy.
Typical use cases
- Input masks for recurring data capture (creditor checks, contract registry, master-data maintenance) with validation and audit trail
- Import pipelines: read CSV/XLSX, validate against schema, write to target database, generate error report
- PDF generators with reproducible layout: quotes, invoices, certificates from structured data
- Handover tools between departments: status workflows, automatic escalation, audit column
- Consolidation tools: collect from multiple sources, normalize, merge into a central tool
- Mini web apps with FastAPI + HTML templates when Excel/Access is not enough but a full web project is overkill
Concrete benefits
- Small scope, fast value: a first runnable tool in 1-3 weeks, not 6 months of enterprise planning
- Handoverability: code in Git, README, clear ownership. No more 'the one tool only Marco understands'
- Maintainability: a second developer takes the tool over in 2-4 days depending on complexity
- Data quality: validation at input prevents the typical 'Excel input errors' (date as text, period vs comma, missing required fields)
- Scalability: what starts as a small tool can grow cleanly if the demand really gets bigger
How we work together
Scope the need (60-90 min)
Who does what how often? Today's pain points? Inputs, outputs, frequency? Output is a short target description with clearly bounded scope.
Architecture decision
Excel-VBA, Access, or web app? SQLite, SQL Server, or PostgreSQL? Standalone or integrated with existing systems? Trade-offs in writing.
MVP implementation
First runnable version with the most important workflow. Real (anonymized) data as test set. Iteration with the team.
Handover + optional retainer
Code in Git, README, deployment guide, live walkthrough. Optional retainer for maintenance and extensions.
Frequently asked questions
Do we need a real database or is Excel enough?
Rule of thumb: up to 50000 rows and 5-10 users Excel or Access suffices. Above that SQL Server or PostgreSQL becomes realistic. For multi-user parallel writing almost always a real database, even for small data, because Excel locking is unreliable.
Who maintains it later?
Three options: you (code in Git, docs, optional short training), retainer with me, or a mix. The codebase is always handover-ready so a second developer can pick up in days.
Can the tool grow later?
Yes, provided the architecture matches expected growth. Excel tools grow limitedly, Access to about 5 million rows, custom web apps practically unlimited. In the architecture decision we factor a realistic 3-5-year horizon.
What does a typical internal tool cost?
Small Excel/Access tool with clear scope: 5-12 working days, €4000-12000 net. Web app with database backend: 10-25 working days. After the scoping workshop you get a real range.
We already have seven small tools in the house. Consolidate or let them live on?
Depends on the pain. If the seven tools coexist and nobody complains: document and let them live. If they conflict or cause constant problems: pick two or three to consolidate. Never touch all seven at once.
Related services
Plan an internal tool or consolidate existing ones?
Describe the need in a few sentences or show the current Excel/Access tangle. You get an assessment with a concrete proposal for how to proceed.