Deploy & release monitoring
Catch Broken Deployments Before Your Users Do
You shipped at 5 PM. The deploy looked clean. CI passed. But a cache never cleared and the page is now loading files that no longer exist — your pricing page has lost its styling and your signup form won't submit. Every page still answers, so nothing alerts. Sitewatch checks your pages and every file they load, so a broken deploy gets caught on the next check, not by your customers.
- Spots when a deploy quietly changes the page in ways you did not intend
- Catches redirect loops and pages that suddenly point to the wrong address
- Confirms every failure with a retry, so a mid-deploy blip never pages you
Post-deploy regression detected
Affected assets
- ASSET_MISSING: /js/app.3f8a1c.js returned 4046:00 AM
- Main stylesheet arrived as a web page, not a stylesheet6:00 AM
- HTML fingerprint changed on /pricing6:00 AM
- All assets OK on /about (no regression)6:00 AM
01The post-deploy gap
CI says green. Your visitors see a broken page.
| Scenario | CI / uptime checks | Sitewatch |
|---|---|---|
| Post-deploy verification | CI passes, then nothing watches prod | Every check re-verifies the live page after each deploy |
| HTML change detection | Not available | Each check compared against the last known-good version |
| Redirect regressions | Status code only | Loop and host-drift detection on every check |
| Performance baseline | Fixed thresholds or none | Automatic response-time baseline regression detection |
| Deploy-window noise | Alerts on the first blip | 2-of-3 retry filters rolling-deploy transients |
Post-deploy verification
- CI / uptime checks:
- CI passes, then nothing watches prod
- Sitewatch:
- Every check re-verifies the live page after each deploy
HTML change detection
- CI / uptime checks:
- Not available
- Sitewatch:
- Each check compared against the last known-good version
Redirect regressions
- CI / uptime checks:
- Status code only
- Sitewatch:
- Loop and host-drift detection on every check
Performance baseline
- CI / uptime checks:
- Fixed thresholds or none
- Sitewatch:
- Automatic response-time baseline regression detection
Deploy-window noise
- CI / uptime checks:
- Alerts on the first blip
- Sitewatch:
- 2-of-3 retry filters rolling-deploy transients
02Why it matters
Every deploy is a chance to break something. Know when it happens.
Missing asset detection
A deploy changes bundle filenames but the HTML still references the old ones. Sitewatch checks every script, stylesheet, and image -- a 404 or 410 on any of them triggers an incident.
Right file, right type
CDN misconfigurations after a deploy can serve JavaScript as text/html or CSS as application/octet-stream. Browsers silently reject them. Sitewatch catches the mismatch.
HTML fingerprinting
Every check is compared against the last known-good version of the page, so a deploy that quietly changes something you did not mean to touch shows up immediately.
Redirect regression detection
Routing changes in a deploy can create redirect loops or send users to the wrong host. Sitewatch flags REDIRECT_LOOP and HOST_DRIFT incidents automatically.
Noise-free confirmations
2-of-3 retry confirmation means transient errors during a rolling deploy window do not create incidents. Only persistent failures trigger alerts.
Six alert channels
Get notified via Slack, email, SMS, webhook, PagerDuty or Opsgenie. Each alert names what failed, which page it affects and what came back, so triage starts immediately.
Automatic performance baselines
Sitewatch calculates response time baselines automatically from your site's history. Regressions are detected without manual threshold configuration — if your site slows down beyond its normal range, you'll know.
03What makes a page slow
Where the seconds actually come from.
Slow is rarely one thing. Select a cause to see how it creeps in — and how Sitewatch catches it.
payload
Page weight
✕How it fails
A release ships an uncompressed image or an extra library and the page quietly triples in size.
✓How Sitewatch detects it
Measures total page size on every check and compares it against your normal range.
Page weight
payloadHow it fails — A release ships an uncompressed image or an extra library and the page quietly triples in size.
How Sitewatch detects it — Measures total page size on every check and compares it against your normal range.
Scripts
executionHow it fails — A new dependency blocks the page from becoming usable, even though it still loads.
How Sitewatch detects it — Tracks the files the page pulls in and flags when that set changes unexpectedly.
Images
mediaHow it fails — Full-resolution images ship straight from a CMS upload with no resizing.
How Sitewatch detects it — Records the size of every image the page requests, not just whether it loads.
Server response
originHow it fails — The backend gets slower under load and every page inherits the delay.
How Sitewatch detects it — Records response time on each check and compares it to your rolling baseline.
04Detection coverage
What gets caught after a deploy
Asset failures
- ASSET_MISSING -- JS, CSS, or image returns 404 or 410 after deploy
- A file arriving as the wrong kind of file, which browsers then refuse
- A page or file returning a server error, or not responding at all
Page-level regressions
- REDIRECT_LOOP -- routing change creates infinite redirect cycle
- HOST_DRIFT -- page unexpectedly resolves to a different host
- NON_HTML_PAGE -- expected HTML page returns non-HTML content
- Page output that differs from the last known-good check
05Simple and reliable
How deploy monitoring works
- 01
Fetch and parse
Sitewatch fetches your page over HTTP and parses the HTML to extract every script, stylesheet, and image reference.
- 02
Check and fingerprint
Every file the page needs is requested to confirm it is there and is the right kind of file. The page itself is fingerprinted so structural changes stand out.
- 03
Confirm with retries
Any detected failure is retried using 2-of-3 confirmation. Only persistent issues create an incident -- no noise from transient deploy windows.
- 04
Alert your team
Confirmed incidents alert you across your configured channels — Slack, email, SMS, webhook, PagerDuty or Opsgenie — each naming what failed, which page it affects and what came back.
06What you get
Outcomes, not a feature list.
Catch the deploy that made everything slower.
Regressions rarely announce themselves. A release adds weight or drops a file, the page keeps loading, and nobody notices until conversion drops. Sitewatch compares every check against the last known-good version and flags the difference.
6
Incident types detected
2-of-3
Retry confirmation
5–30 min
Check intervals
Your CI passed. But does your site actually work?
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07FAQ
Frequently asked questions
Sitewatch opens your pages, works out every file they need — scripts, stylesheets, images — and checks each one. If a file has gone missing, is erroring, or arrives as the wrong kind of file, that becomes an incident. The page itself is also fingerprinted, so an unexpected structural change after a deploy is caught even when nothing is technically broken.
Unlikely. Sitewatch uses 2-of-3 retry confirmation. A failure must be reproduced consistently before an incident is created. Transient errors during a deploy window are filtered out. A 30-minute alert cooldown also prevents repeated notifications for the same problem.
Check intervals are configurable per site — from every 30 minutes on Free up to every 5 minutes on Pro. You can also trigger a manual check anytime from the dashboard — ideal for verifying a deploy immediately after release.
Six channels: Slack, email, SMS, webhook, PagerDuty and Opsgenie. Per-site routing sends alerts to the right team, and each alert names what failed, which page it affects and what came back.
No. Sitewatch works entirely externally by fetching your pages over HTTP and parsing the HTML. There are no scripts, SDKs, or agents to install. Setup takes about two minutes.
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