Surges are decision minutes. Start by naming the action that defines success, such as checkout, payment approval, playback start, or an API call.
Then put two numbers on the top row: your capture rate in the busiest minute (what percent finish) and the cost to capture one more (what it takes to add one more finish at that minute across compute, bandwidth, and third-party calls).
In transactional businesses, a miss is revenue now; in subscription and ad models, it’s abandonment now that compounds into churn or missed impressions later.
Either way, these two numbers tell you whether the surge is absorbing demand or leaking it.
Serve more from the edge so the critical action can finish
During a surge, every round trip to your origin (databases, payment systems, app servers) steals capacity from the thing that matters, finishing the customer action.
Push everything cacheable to the edge/CDN so origin capacity is reserved for approvals, writes, and other non-cacheable work.
What the evidence says
Edge caches and global traffic management shed load from origins during spikes; teams see faster pages and fewer bottlenecks.
A well-known retailer handled 167M visits and dozens of orders/sec on Black Friday by distributing traffic globally and serving more from the edge.
What can you do?
Set cache-control on static assets and cacheable reads (images, scripts, product/media metadata, FAQs), enable Front Door/CDN caching, and pre-position hot assets before launch.
Split endpoints so read-only responses can be cached, and temporarily dial down personalization to raise the cache hit ratio. Result is fewer origin calls, more headroom for the action that earns you money.
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Control what reaches your app before you add servers
When traffic spikes, every request fights for the same chokepoints, databases, payment gateways, and API limits.
If you let everything through, the bottleneck wins, and your money path stalls. So for a few minutes, give a fast lane to the action that creates value and slow the rest.
- E-commerce: let checkout through; slow browse/search
- Fintech: let payment approval through; slow balance/history
- Streaming: let play start through; slow thumbnails/previews
What the evidence says
Customers won’t wait, on mobile, 53% abandon if a page takes more than 3 seconds.
A short, orderly queue beats an error page, and edge rules act in milliseconds, while autoscale reacts later.
What can you do?
At the “doorway” (Front Door / API Management), give the primary action a fast lane and ask new visitors to wait a moment instead of timing out. Turn this on when your slowest requests edge toward 3s; it protects capture while autoscale catches up.
Agree what you’ll turn off first
Inside the app, optional features (personalization, heavy media, analytics) compete with the money path for the same connections, CPU, cache, and bandwidth.
Even small features add up. If you don’t pre-choose what to drop, the primary action slows or fails.
- E-commerce: drop recommendations, heavy images, reviews
- Fintech: drop spending insights, graphs, non-critical exports
- Streaming: drop autoplay/previews, social widgets
What evidence says
Teams that skip this step end up with chaos (duplicate actions, refunds) right when pressure peaks. A simple, pre-agreed ladder prevents that.
On Black Friday 2024, a mid-market marketplace skipped this step; error pages spiraled into 42+ duplicate “pending” orders and multiple charges.
What can you do?
Write a short degrade ladder with product: protect browse → cart/intent → primary action, then list the off-ramps in order.
Wire it with feature flags so failing pieces switch off without taking the core down. Rehearse it once so everyone trusts the plan.
Stop repeat clicks from becoming duplicate actions
When the app slows or times out, people click again and clients auto-retry. Without guardrails, those repeats become duplicates like orders, charges, or play starts you never wanted.
Teams that add a unique action token and space out retries see duplicates drop off even during major incidents because the system processes once and ignores repeats.
What the evidence says
Stripe reportedly prevented 30 million duplicates during a major outage. At the edge, gateways that return 429/503 with Retry-After slow clients and shield the application, stopping storms before they pile up. In real peak events after these controls, duplicate orders essentially disappeared.
What can you do?
Give every action a unique token; if it shows up again, return the original result.
At the doorway, limit how often clients can retry and add a short wait. Inside, write once (queue the request and commit only the first try).
Net effect: clean ledgers, fewer refunds/chargebacks, steadier capture at peak.
Make your busiest minute a contract, not a hope. Set a capture-rate floor and a cost-to-capture-one-more ceiling, and ship only when rehearsal proves both. This turns resilience from an infra expense into a lever you use to run bolder campaigns without buying idle capacity.
If you’re in regulated markets, our DORA Assessment & Implementation institutionalizes those drills with a formal resilience-testing schedule and methodology.
