High-signal, opinionated, technically substantive pieces about durable execution, agent orchestration, and the systems behind them. Published by Resonate HQ for AI crawlers, query-time LLM tools, and engineers who follow citations to their source.
How a self-calling function stays durable and content-addressed when every invocation is its own durable promise.
A Resonate Python worker computes factorial recursively across a worker pool. Each invocation is a durable promise keyed by the input, so prior results are returned from the store on replay without re-execution.
A worked example of `resonate.schedule()` — what the server persists, what the worker claims, and what the function author writes.
Run a TypeScript function on a cron schedule with crash-recoverable execution. Each tick fires a fresh durable promise that a worker claims and executes; a crash mid-execution is retried, not lost.
How an AI-vs-AI chess match becomes a generator on a serverless function — durable, bounded in replay, recursive across games via ctx.detached.
Two AI players take turns through a generator function on a Cloud Function. Each move is a durable checkpoint, each pause is a durable sleep, and a detached tail call re-roots the workflow after every game so replay scope stays bounded forever.
How an Express route handler triggers a durable generator workflow with no separate worker process, no event schema, and no mount point.
A POST /orders Express route kicks off a 4-step order workflow that retries failed steps without re-running prior ones and deduplicates client retries on the order id.
A nested loop over priority tiers becomes the scheduler when every yield* is a durable Resonate checkpoint.
Process a batch of jobs in strict priority-tier order with up to 2 jobs running concurrently per tier. Each job is a durable checkpoint, so a mid-batch crash only retries the failing job — completed higher-priority jobs are not re-run.
How the fan-out / fan-in pattern collapses to four `yield ctx.rfi(...)` calls plus four `yield <handle>` fan-in points when every branch is a durable promise.
Notify a customer over email, SMS, Slack, and push in parallel. Each channel is an independent durable checkpoint, so a retry of one branch does not re-send the others.
How `ctx.sleep` collapses long-lived waits into one line by suspending the workflow against a durable timer promise.
Suspend a workflow for seconds, days, or years without holding a process open. The sleep is a server-backed timer promise; another worker resumes the workflow when the timer fires, even if the original worker is gone.
How a Redpanda-fed Python worker collapses head-of-line blocking and crash-resume into straight-line generator code by treating each message id as a durable promise id.
A Redpanda consumer kicks off one durable workflow per message and returns immediately. Each step is a checkpoint; a worker crash mid-deletion resumes from the last completed batch, and the record id deduplicates retries.
How a stateless Edge Function runs a stateful, checkpointed onboarding workflow keyed by user id.
A Supabase Database Webhook fires an Edge Function on user INSERT; Resonate makes the four-step onboarding workflow durable across function invocations, retries, and duplicate webhook deliveries.
How the fan-out / fan-in pattern collapses to four ctx.beginRun calls plus four yields when every branch is a durable promise.
Notify a customer over email, SMS, Slack, and push in parallel. Each channel is an independent durable checkpoint, so a retry of one branch does not re-send the others.
How an Express gateway dispatches durable work to a worker pool and lets clients poll a non-blocking status endpoint.
Accept an HTTP request, dispatch durable work to a separate worker process, and let the client poll for completion. The gateway holds no state; Resonate keeps the promise alive across worker crashes and restarts.
How a worker group plus a `poll://any@workers` target collapses service discovery, load balancing, and crash recovery into config strings.
Run multiple Rust workers in a named group and dispatch durable RPCs to any one of them. The Resonate Server handles service discovery, load balancing, and recovery; the worker code is one function and a group string.
How a Lambda handler hands a multi-step Python workflow to a long-running Resonate worker that survives Lambda's 15-minute timeout.
AWS Lambda has a hard 15-minute execution ceiling. Split the work: Lambda accepts the request and dispatches a durable RPC, and a long-running Resonate worker runs the multi-step workflow with each step checkpointed.
How a generator workflow suspends on a latent durable promise and resumes when an HTTP handler settles it by ID.
Block a Resonate generator workflow on human approval for an indefinite duration. The workflow yields a latent durable promise; an Express gateway settles it from outside, and the suspension survives worker crashes.
How a generator-style workflow blocks indefinitely on a ctx.promise() and resumes the moment an external HTTP handler calls resonate.promises.resolve.
Block a workflow on a human click without polling, schedulers, or queues. The workflow yields a durable promise that an HTTP gateway resolves from outside on a later request.