The choice rarely comes down to technology. It depends on your process, what you are willing to change in how you work, and what you want to own in the end.
When an off-the-shelf ERP is enough
If your need is standard and common, an ERP or off-the-shelf tool is often the right call. You adopt a proven setup, you start fast, and you pay a subscription. The trade-off is clear: you bend your business to the tool, not the other way around.
When custom becomes rational
Custom takes over the day the standard tool slows you down more than it helps. The signals are concrete: you constantly export to Excel to make up for what the ERP cannot do, your process is too specific to fit the boxes, or you need to own the code and your data.
The real three-year cost
An ERP rented at 600 € per month costs 21,600 € over three years, and you own nothing. A first custom brick costs 5,000 €, once, and the code is yours. Many SMBs pay for a heavy tool and use only a fraction of it. The day you spend your weeks working around your software, the math changes.
The decision grid
Ask three simple questions. Does your need match a standard offer? Do you want to integrate everything at once or move in steps? Do you need to own the code? If your answer is "specific process, in steps, and yes I want to own it", custom software cut into bricks is probably the right answer.
To dig deeper, read our page on custom software.