Technical Debt.

The image comes from Ward Cunningham and is deliberately financial. There is deliberate debt — you choose the quick option to hold a deadline and know what has to be made up later. And there is inadvertent debt, arising from missing knowledge, time pressure or changing responsibilities. It affects more than lines of code: a data structure that does not allow for the edge case, missing documentation, a manual deployment step, or a dependency not updated for years are all debt that costs interest.

It shows up as symptoms rather than as a metric. Changes that sound small always take longer. Bugs return elsewhere after being fixed. New developers take unusually long to become productive. There are places in the system nobody volunteers to work on. And the answer to new requirements increasingly becomes 'not possible' instead of 'this is what it costs'. A team saying those sentences does not have a motivation problem but a structural one — and it should be named as such rather than as a question of pace.

A typical origin story: a proof of concept demonstrates that data migration from the legacy system works. Because it runs, it is not replaced but extended — credentials hard-coded, no error handling, assumptions that only hold for the test dataset. Two years later the invoicing run depends on it, nobody knows the code, and every change is a risk. Paying the debt back then costs a multiple of what a clean rebuild would have cost at the start. This is not an isolated case but the most common pattern in grown SME systems.

How to handle it is a commercial decision, not a matter of faith. What works is a fixed share of capacity — often around ten to twenty per cent — reserved for repayment: keeping dependencies current, adding tests for the critical paths, automating manual steps. Transparency in the quotation matters just as much: if the quick option is chosen, the later effort belongs in writing. And not every debt has to be repaid. For a system that will be replaced within eighteen months anyway, living with the debt is the commercially correct answer.