Engineering teams face a documentation paradox: on-call engineers need instant, actionable information during incidents, while new hires need comprehensive context to understand systems. These audiences have completely different needs, yet maintaining separate documentation systems creates silos, duplication, and inevitable drift.
What this article solves: How to create documentation that serves both on-call responders and new team members without duplicating effort or maintaining separate systems.
Who this is for: Engineering teams struggling with stale runbooks, overwhelming onboarding docs, or maintaining multiple documentation sources that quickly fall out of sync.
The Documentation Divide: Why One Size Doesn't Fit All
On-call documentation and onboarding documentation serve fundamentally different purposes. During a 3 AM incident, an engineer needs to know exactly what commands to run and which services to restart. A new hire starting their first week needs to understand why those services exist and how they fit into the broader architecture.
Traditional approaches force teams to choose: write for the crisis (terse runbooks) or write for learning (comprehensive guides). Most teams end up with runbooks that reference deprecated services and onboarding docs that assume knowledge new hires don't have. The people who know the systems best often write the worst documentation because they can't remember what it's like not to know.
The solution isn't better wiki discipline. It's recognizing that both audiences need the same underlying information, just structured and presented differently. When documentation is generated from the actual work—GitHub PRs, Slack threads, Datadog alerts that woke someone up, and Linear or Jira tickets—it can serve multiple purposes without maintaining two wikis.
Understanding Your Audiences: Different Mental Models, Same Information
On-call engineers operate in crisis mode. They need documentation that reduces cognitive load and provides clear decision trees. Key characteristics:
- Time pressure: Every minute counts during incidents
- Stress response: Limited working memory under pressure
- Action-oriented: Need to do, not understand why
- Context switching: Often unfamiliar with the specific service failing
New hires operate in learning mode. They need documentation that builds mental models and explains relationships. Key characteristics:
- Time abundance: Can spend hours understanding one concept
- Full cognitive capacity: Not under stress, can process complex information
- Knowledge-building: Need to understand why, not just what
- System-wide thinking: Trying to map the entire engineering landscape
The insight is that both groups need access to the same core information: what services do, how they interact, what can go wrong, and how to fix it. The difference is in presentation and entry points.
Building Layered Documentation That Serves Both Audiences
Effective documentation architecture uses progressive disclosure—starting with essential actions and allowing readers to drill down into context when needed. This serves on-call engineers who need quick answers and new hires who need deep understanding.
Start with the action layer. Every piece of documentation should begin with what to do. For a service that's down, start with restart commands. For a new feature, start with how to use it. This immediately helps on-call responders while giving new hires a concrete starting point.
Add context layers progressively. After the immediate action, provide the why: what this service does, how it fits into the system, what business logic it contains. Use expandable sections, linked deep-dives, or clear heading hierarchies so on-call engineers can skip and new hires can explore.
Connect to source material. The best documentation links back to the PRs that implemented features, the Slack threads where decisions were made, and the tickets that drove requirements. For on-call, add Datadog monitor context so "restart the service" is paired with "this is the graph that told us it was broken." For onboarding, add Notion or Google Drive links where your team keeps playbooks and RFCs. Same facts; different front door.
Practical Implementation: From Scattered Wikis to Single Source
Here's a practical checklist for transforming your documentation approach:
- Audit existing documentation for overlap between runbooks and onboarding materials
- Identify core system information that both audiences need (service purposes, dependencies, common failure modes)
- Structure new documentation with action-first, context-second hierarchy
- Link documentation directly to source PRs, code reviews, and decision discussions
- Create clear entry points for different use cases (incident response vs. learning)
- Establish documentation generation from existing workflows (PRs, Slack, Linear)
- Test documentation with both on-call scenarios and new hire onboarding
- Set up automatic updates when underlying systems change
The key is generating documentation from work that's already happening. When architectural decisions are captured from Slack threads, when feature explanations are extracted from PR descriptions, and when troubleshooting steps are documented during actual incidents, the documentation stays current without manual maintenance.
Making It Work: Integration Over Separation
The most successful teams don't maintain separate documentation systems. They create documentation that adapts to the reader's needs. A service overview might start with restart commands for on-call engineers, then expand into architecture details for new hires, then link to the original design discussions for deep context.
This approach works because it mirrors how engineers actually learn systems—starting with practical tasks, then building conceptual understanding. New hires who start by learning how to restart services in staging environments build confidence and practical knowledge before diving into complex architectural concepts.
Modern generative documentation platforms make this possible by extracting information from GitHub, Slack, your tracker, and—when relevant—Datadog and wiki sources, then presenting it in formats optimized for different use cases. The same source material becomes both actionable runbooks and comprehensive onboarding guides.
Conclusion
On-call documentation and onboarding documentation don't need separate maintenance—they need smart presentation of shared information. When documentation is generated from actual work and structured with progressive disclosure, it serves both crisis response and learning without the overhead of maintaining multiple systems.
Ready to stop maintaining separate documentation systems? ScopeDocs generates source-linked documentation from GitHub, Slack, Linear or Jira, Datadog, Notion, and the rest of your stack—so one source serves both on-call responders and new team members.