Zapier vs n8n vs Relay vs Custom built. the decision framework I actually use
I got tired of seeing this question tool-by-tool so I wanted to share a framework that's held up pretty consistently across different use cases.
Here's how I think through it, having worked with teams in different sizes:
Use Zapier if: Your team is non-technical and needs to own the workflow independently. The trigger/action is simple and unlikely to change. You need it running this week. The moment a workflow needs conditional logic more than 2 levels deep, Zapier starts fighting you.
Use n8n if: You have at least one person who is comfortable reading JSON and won't panic when a node errors. You need branching logic, sub-workflows, or custom code steps. You want self-hosted for cost or data reasons. n8n's ceiling is much higher than Zapier's, but its floor is also lower. Broken workflows require someone to actually fix them.
Use Relay if: The workflow has humans in the middle of it and that's not going away. Approvals, handoffs, review steps, routing, notifications, escalation paths, the stuff that sounds simple until 5 people touch the same process across Slack, email, docs, and internal tools. Relay makes more sense to me when the problem is operational coordination rather than pure automation.
Go custom if:
The workflow is core to how your product or ops works and will change frequently. You're integrating with internal systems that have no pre-built connectors. You need full observability (logs, retries, alerts) baked into the system, not bolted on. Custom costs more upfront and needs a real engineer, but it pays back when the workflow scales or the requirements shift.
The mistake I see teams often make is starting with Zapier, hitting the ceiling, migrating to n8n, then eventually building custom, wasting weeks or even months instead of making the right call once.
The answer almost always depends on team composition, not the workflow itself.
What made you choose the stack you're on? And what would you do differently?