The short answer
Technical debt behaves like a compounding tax, silent until it shows up in delivery times and then in the departure of the best engineers. A favorable ARR per R&D head ratio at one point in time can hide a dangerous trajectory. This white paper treats debt as a financial liability to document, with a repayment plan, not as a purely technical topic invisible to the Board.
Key takeaways
- A good ARR per head ratio in one quarter proves nothing: you need its trajectory over eight quarters.
- Code, architecture and test debt eventually slows every feature and inflates time to market.
- A light audit is enough to frame the risk: test coverage, age of the core, obsolete dependencies.
- Documenting debt as an explicit liability changes the conversation with the Board and the fund.
A compounding tax that shows up late
A favorable ARR per R&D head ratio can stay excellent for several quarters while code, architecture and test debt piles up. Four to six quarters later, the same ratio melts. The debt stays silent until it appears in delivery times, then in the turnover of engineers tired of working on a fragile core.
Pre-deal, asking for the ARR per head trajectory over eight quarters, crossed with a light audit of accumulated debt, is the cheapest way not to buy a hidden liability.
A lived case: three months of frozen roadmap
The cost of one sacrificed quarter is lower than the downtime and lost customer trust of debt left to run.
