Durable execution for serverless workflows
Inngest
Durable execution lets Inngest sell reliability without asking developers to give up serverless. Instead of trusting one long process to stay alive, Inngest saves the output of each step outside the function runtime, then replays the workflow from the last completed step after a timeout, cold start, deploy, or infra move. That makes day or week long jobs practical inside Lambda, Vercel, and container based apps, where normal request lifetimes are short and workers are disposable.
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The practical developer win is that expensive work does not get repeated. Inngest executes each step as its own request, persists the result, memoizes completed steps, and injects saved outputs on the next run. If step 7 fails, steps 1 through 6 are skipped instead of rerun, which matters when those steps include API calls, database writes, or long waits.
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This is the clearest separation from visual automation tools like n8n and from cloud native orchestrators like AWS Step Functions. n8n is built around a visual editor and custom code for automation workflows, while Step Functions is tightly tied to AWS and long runs must stay within service limits, including a one year maximum execution and event quotas that can require splitting workflows across executions.
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The business implication is that Inngest fits the modern app stack that already deploys on Vercel or Lambda. Vercel is the home base for many frontend teams, but its functions are still ephemeral compute. Inngest sits beside that stack and adds retries, waiting, traces, logs, and concurrency control for jobs like onboarding flows, background syncs, and AI pipelines without forcing a move onto a heavier workflow system.
The next step is for durable execution to become standard plumbing for AI products and event driven backends. As more apps chain model calls, human approval steps, rate limits, and delayed follow ups, the winner will be the platform that makes those long lived flows feel as easy to write as a normal function, while staying portable across clouds and runtimes.