On-Call Tools for Agencies Running Client Software

incident.io is built around the assumption that your team runs the response inside its own Slack. If you are responding inside the client's Slack instead, because that is where their stakeholders are, you either need incident.io deployed in their workspace or you are coordinating across two chat systems at once while the outage is live.

PagerDuty's web-based incident record does not care whose Slack anyone uses, which makes it easier to keep one paging setup even when every client's collaboration tooling looks different. For an agency running several client codebases at once, that platform independence can matter more than any single workflow feature either tool offers.

Both platforms price primarily by the number of people who can be paged or who touch the incident tooling. For an agency, that number is not stable: it might include your engineers, a client's ops lead who wants visibility, and a subcontractor rotating through for a specific project.

Before signing an annual contract with either vendor, map out how many active seats a typical engagement actually needs, and check whether the vendor's tiering punishes you for adding a client stakeholder as a light viewer rather than a full responder. A contract sized for your busiest quarter can leave you overpaying for the other three.

When a retainer ends, the client keeps the code, the infrastructure, and usually the monitoring. Whether they keep the incident history depends entirely on whose account it lived in. If you ran incidents through your own incident.io or PagerDuty account, the client is left with no record of past outages unless you export and hand it over deliberately as part of offboarding.

Build that export into your engagement close-out checklist rather than discovering the gap when a client asks for a full history of postmortems after you have already moved your team on to the next project.

An offboarding checklist when an engagement ends:

• Export incident history and postmortems so the client keeps a record of past outages.
• Transfer or remove your team's access to the account.
• Hand over any runbooks embedded in the tool.
• Confirm the client has an active on-call rotation before your last responder is removed.

Regardless of whose tool it is, the underlying discipline matters more than the label on the escalation policy. The gap between a team that recovers from a failed deployment in minutes and one that takes weeks usually comes down to whether rollback is a rehearsed, one-command action or something an engineer improvises live while a client watches the incident channel.

For a shop juggling several client codebases, that rehearsal has to happen per client, since a rollback script that works cleanly on one client's infrastructure may not exist at all on another's, especially where a client's own team wrote the original deployment pipeline before you took over support.

For a single client with a modern stack and a Slack-first culture, incident.io tends to be the faster setup: less configuration, and the client can see exactly what happened without learning a new tool. For a client with an existing PagerDuty contract, multiple legacy integrations, or a preference for a web dashboard over Slack, adopt their existing tool rather than introducing a second one just because your team prefers it.

The right platform for an agency is usually whichever one the client will actually keep using after you leave, not the one your own engineers find most comfortable during the engagement itself.

Say one engineer covers overnight support for a client running incident.io and another running PagerDuty, because each adopted its own tool before your agency got involved. That engineer needs two separate paging setups configured correctly on their phone, and a habit of checking which client's system is actually alerting before diagnosing anything, since the fix for one client's stack rarely applies to the other's.

Document which tool belongs to which client somewhere more durable than the engineer's memory, ideally in the same runbook that already lists each client's rollback steps and escalation contacts, so a new team member covering that rotation for the first time is not guessing.