Orch8 vs Temporal

Temporal: event replay

Temporal stores every event (step started, step completed, timer fired, signal received) in a history log. On recovery, it replays the entire history to reconstruct the workflow state.

Where this excels:

• + Full audit trail with every event preserved
• + Time-travel debugging — replay to any point in history
• + Strong consistency guarantees for distributed transactions

Trade-offs to consider:

• → History grows with every event — long-running workflows (days/weeks) accumulate large histories
• → Recovery time scales with history length — more events means longer replay
• → Workflow code must be deterministic — no direct API calls, no timestamps, no random values in workflow functions

Orch8: state snapshots

Orch8 persists the full execution state (current position, step outputs, context) as a snapshot after each step. On recovery, it loads the snapshot and resumes from the last completed step.

Where this excels:

• + O(1) recovery time — regardless of how long the workflow has been running
• + No determinism constraints — handlers are plain HTTP endpoints
• + Ideal for workflows that run for days or weeks (campaigns, monitoring, agents)

Trade-offs to consider:

• → No time-travel debugging — you see the last snapshot, not intermediate states
• → Full event-level audit requires additional logging in handlers

Temporal — workflow code with determinism constraints

// Temporal workflow — must be deterministic
async function onboardingWorkflow(user: User) {
  // Cannot call APIs directly in workflow code.
  // Must use activities (separate functions):
  await activities.sendWelcomeEmail(user);

  // Cannot use Date.now() — must use workflow time:
  await workflow.sleep('3 days');

  // Cannot use Math.random() — must use deterministic
  // alternatives for A/B testing
  await activities.sendFollowUp(user);
}

Orch8 — JSON definition with plain handlers

// Orch8 — no determinism constraints
// Handlers are plain HTTP endpoints:
app.post('/workers/send_welcome', async (req, res) => {
  // Call APIs directly. Use Date.now(). Use Math.random().
  // The output is memoized — safe on retry.
  const result = await sendEmail({
    to: req.body.context.data.email,
    template: 'welcome',
  });
  res.json({ sent: true, id: result.id });
});