When should I choose custom development over SaaS?

Choose custom development when your workflows are core to your competitive advantage and you cannot afford to be limited by what a SaaS vendor decides to ship. When SaaS subscription costs exceed $50,000 per year and would do so for the foreseeable future. When you need data sovereignty for compliance reasons (HIPAA, PCI, ISO 27001) that SaaS cannot guarantee. When you need integrations with internal systems that no SaaS will build for you. When you have outgrown the limits of a low code platform and the workarounds are now costing more than a proper build.