Part of The OPC Manual · By Adine Tjeenk Willink
Every OPC needs a stack. The question is not whether to have one — it is which tools, in what order, at what cost. This section is the framework. The decision rules for adding new tools are in 2.3. The specific Stratum example is in 2.4.
Most stack advice for early-stage companies is wrong for an OPC. It is written for teams. It assumes someone other than the founder will configure the tools, train new joiners on them, and absorb the cost of switching when the choice turns out badly. None of that applies when there is one person doing all of it.
The OPC constraint is different. The founder is also the IT department, the procurement function, the integration layer, and the person who has to remember why a tool was chosen six months later. Every tool added to the stack is paid for not just in subscription cost but in attention, context-switching, and the ongoing work of keeping it useful.
A well-built OPC stack is small. Smaller than it should be on paper. The discipline is in what is deliberately not in it.
Buy only what generates revenue or prevents a compliance failure. Everything else waits.
This is the one-line test. Before adding any tool, the question is: does this make revenue more likely, or does it protect against something that could cost more than the tool? If neither, it waits.
The secondary test is the team constraint: nothing gets added to the stack until AI and the human layer cannot cover it. When a gap appears that those cannot fill, that is when a tool conversation happens. Not before.
The two tests catch most premature additions. The third test — covered in 2.3 — is the trigger: every tool on the "not yet" list should have a defined event that would justify adding it. "When we hit fifty active deals." "When we sign the first enterprise contract." "When the founder is spending more than two hours a week on this manual step." Without a trigger, "not yet" becomes "never" — or worse, "whenever I feel like it."
The OPC stack organises around three layers. Every tool belongs to exactly one. If a tool does not fit cleanly into one layer, that is a signal it may not belong.
Input. Where data enters the system. Meeting capture, lead enrichment, prospect research, document intake.
Brain. Where information is stored, processed, and turned into decisions. The knowledge base. The AI layer. The CRM if it is separate from the knowledge base.
Output. Where decisions become action. The pipeline tool. The accounting and invoicing layer. The contract signing layer. The communication layer.