Edge Functions
Short-lived compute at the CDN, its runtime limits, and what must stay at origin.
4 to work through
-
intermediate
A team wants to move logic to edge functions. What are the genuine constraints, and which logic should stay at the origin?
2 min answer -
advanced
Shortly before 10:00 UTC on 8 June 2021 a Fastly customer pushed a valid configuration change and about 85% of the network began returning errors. The bug had shipped on 12 May and lay dormant. Detection took about a minute and 95% of the network was recovered within 49 minutes. What class of failure is this?
2 min answer -
advanced
What genuinely belongs in an edge function, and what is the failure mode of putting too much there?
1 min answer -
advanced
Which parts of a personalised page would you compute at the edge, and where does each piece of state live?
2 min answer
3 terms in this topic
Cloudflare Workers: Isolates Instead of Containers
Running thousands of tenants per process using V8 isolates rather than containers, trading runtime flexibility for near-zero cold start and extreme d…
conceptCold Start at the Edge
The initialisation delay when a request reaches a location with no warm instance, which at the edge occurs far more often because traffic is spread a…
toolEdge Functions
Small units of code executed at points of presence near users — powerful for stateless work, constrained by the limits of the runtime and the difficu…
Neighbouring topics
Edge, Mobile & IoT
General material on architecture beyond the data centre boundary.
Mobile App Architecture
Layering, navigation, background execution, and the platform rules you do not set.
Offline-First
Treating connectivity as an optimisation, with a local store as the source of truth.
Sync & Conflict Resolution
Two devices that both changed the same record while neither could see the other.
CRDTs
Data types that converge without coordination, and the semantics you must accept.
Mobile Release Strategy
Store review, staged rollout, and supporting versions you can never force off.
Push & Background Work
Delivery that is best-effort, and an operating system that will kill your process.
Device Identity
Identifying a thing rather than a person, and rotating a credential you cannot type.
Edge Compute Topologies
Regional, metro, on-premises and on-device, and what each tier is genuinely for.
Edge Data Consistency
Replicated read state at hundreds of locations, and writes that still go to one.
IoT Ingest Architecture
Millions of small, unreliable, frequently duplicated messages arriving continuously.
Device Provisioning
Getting identity and configuration onto hardware at manufacture or first boot.
Fleet Management
Inventory, health, configuration and grouping across devices you will never see.
OTA Updates
Updating firmware over a flaky link, with rollback, and without bricking the device.
Constrained Protocols
MQTT, CoAP and their kin, chosen for power, packet size and intermittent links.
Device Telemetry at Scale
Deciding what a device sends, how often, and what is aggregated before it leaves.
Digital Twin
A server-side model of a physical thing's reported and desired state.
Edge Security & Attestation
Secure boot, hardware roots of trust, and proving what is running on a device.
Physical-World Failure Modes
Power loss, tampering, clock drift, thermal limits, and a truck through the fibre.