Multi-Channel Notification Router

Multi-Channel Notification Router — Workflow Patterns | Dan Stoll

Visual Flow

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When to Use This Pattern

Use multi-channel notification when:

Important alerts are missed because they're buried in email
Different situations require different urgency levels (a system outage should not arrive the same way as a weekly report)
Recipients have different communication preferences (some prefer email, others Teams or SMS)
Your workflows notify people outside of business hours and need to reach them through appropriate channels

How It Works

Urgency	Channel	When	Example
🔴 Critical	SMS + Phone call + Teams	Immediately, 24/7	System down, security breach
🟠 High	Teams message + Email	Immediately, business hours	Approval overdue, SLA warning
🟡 Medium	Email	Within 1 hour	New task assigned, status update
🟢 Low	Digest email	Daily/weekly summary	FYI updates, reports ready

Implementation Guide

Step 1: Define the Channel Priority Matrix

Create a configuration table:

Urgency	Primary Channel	Fallback Channel	Escalation Channel	Max Delay
Critical	SMS	Phone call	Manager SMS	0 minutes
High	Teams	Email	SMS (after 30 min no ack)	5 minutes
Medium	Email	Teams (if opted in)	—	60 minutes
Low	Digest queue	—	—	End of day

Step 2: Collect Recipient Preferences

Let users set their notification preferences:

Preference	Options
Primary channel	Email / Teams / SMS / Push
Quiet hours	e.g., 10 PM – 7 AM
Quiet hours override	Critical alerts bypass quiet hours
Digest preference	Daily at 8 AM / Weekly on Monday
Phone number	For SMS and phone call channels
Teams handle	For direct Teams messages

Step 3: Build the Notification Engine

FUNCTION send_notification(recipient, message, urgency):
    
    prefs = get_preferences(recipient)
    channels = get_channels_for_urgency(urgency)
    
    // Check quiet hours
    IF is_quiet_hours(recipient) AND urgency != "critical":
        queue_for_delivery(recipient, message, prefs.quiet_hours_end)
        RETURN
    
    // Send via primary channel
    primary = prefs.primary_channel OR channels.primary
    send(primary, recipient, message)
    
    // For high+ urgency: set up escalation
    IF urgency IN ["critical", "high"]:
        schedule_escalation(
            delay: channels.escalation_delay,
            action: send(channels.fallback, recipient, message)
        )

Step 4: Implement Each Channel

Channel	Implementation
Email	Standard send email action. Include full details.
Teams	Post adaptive card to user's chat or team channel. Include action buttons (Acknowledge, View Details).
SMS	Twilio, Azure Communication Services, or carrier API. Keep under 160 characters with a link.
Phone call	Twilio voice API or escalation to on-call rotation. For true emergencies only.
Push notification	Mobile app push via Firebase or Azure Notification Hub.
Digest queue	Accumulate messages in a queue, batch-send per schedule.

Step 5: Track Delivery and Acknowledgement

Event	Action
Sent	Log delivery timestamp and channel
Delivered	Confirm delivery (read receipt, webhook confirmation)
Acknowledged	Recipient clicked "Acknowledge" or replied
Not acknowledged	After timeout, escalate to fallback channel
Bounced/failed	Try fallback channel immediately

Example: Production Incident Alert

Monitoring system detects API response time > 5 seconds
Urgency classified as Critical
On-call engineer receives: SMS (immediate) + Teams DM (immediate)
After 5 minutes with no acknowledgement: Phone call to on-call
After 10 more minutes: SMS to backup on-call + Teams post to #incidents channel
Once acknowledged: Email with full details sent to broader team

Tips & Best Practices

Warning

Notification fatigue is real. If you send critical alerts too often, people start ignoring them. Reserve the most aggressive channels (SMS, phone) for truly critical events that happen rarely.

Respect quiet hours. Waking someone up at 3 AM for a medium-priority notification will make them disable notifications entirely. Only break quiet hours for critical alerts.
Include actionable content. Every notification should answer: What happened? What do I need to do? How do I do it? Include a direct link to take action.
Deduplicate. If the same event triggers multiple times in 5 minutes, send one notification with a count, not five separate messages.
Measure and tune. Track open rates and acknowledgement times per channel. If Teams messages get acknowledged 3x faster than email, encourage users to make Teams their primary.

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