Search the practice set
275 questions, 991 terms and 600 topics in 30 areas.
53 results for “Edge, Mobile & IoT”
Unreachable Node
A component you cannot log into, restart or inspect, which removes every operational technique that assumes access to the running system.
Cold 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 across many locations.
Edge Aggregation
Summarising or filtering telemetry at the device or gateway so that only what is needed leaves, which is usually the difference between a viable and an unaffordable design.
Edge Function
Code executed at a CDN point of presence close to the user, in a constrained, fast-starting runtime, typically to modify or route a request before it reaches an origin.
Edge Personalisation
Varying a cached response at the edge on a small number of attributes, so the page stays cacheable while still differing per visitor segment.
Admission Control
Deciding at the edge whether to accept a request at all, based on current capacity, before any work is done on it.
Compute Tier Placement
Deciding which of on-device, on-premises, metro, regional or central compute a workload belongs to, from its latency, data volume and autonomy requirements.
Content Delivery Network
A geographically distributed cache that serves content from a location near the user instead of from the origin.
DAG Dependency
The declared edge stating that one task must not start until another has succeeded, and the difference between that and merely running later.
Forced Upgrade
Blocking an installed client version from operating until it updates, which is the only lever available and is disruptive enough to need a policy.
Global Traffic Management
The layer that decides which region a given user reaches, using DNS, anycast or an edge network, and that performs regional failover.
Ingest Fan-In
The shape of a system receiving many small messages from very many senders, where connection count rather than data volume is the primary constraint.
Origin Shield
An intermediate caching layer between CDN edge nodes and the origin, so a cache miss at many edges results in one origin request rather than many.
Platform Lifecycle Constraint
The operating system's rules about when your process runs, which are not negotiable and invalidate most assumptions carried over from server code.
Read Local Write Global
Replicating read-only state to every edge location while directing writes to a single authoritative region, which is the arrangement most edge data stores actually provide.
Render Location Decision
Where HTML is produced — build time, server, edge or browser — chosen per route by how personalised and how cacheable that route is.
Reverse Proxy
A server that receives client requests on behalf of one or more backends, forwarding them and returning the response.
Secure Boot Chain
Each boot stage verifying the signature of the next before executing it, anchored in immutable hardware, so only authorised software runs.
Timeout Budget
Assigning a request an overall deadline at the edge and passing the remaining time down each hop, so no service works on something already out of time.
A team proposes moving an API to edge functions to reduce latency for international users. What do you check before agreeing?
Where is the data? This is the question that settles most edge proposals. Compute at the edge that calls back to a single region database has moved the compute
A team proposes moving personalisation to edge functions to cut latency. When does that work and when does it backfire?
The principle that decides it The edge is near the user and far from your data. Edge compute pays off for work that needs the request but not your state . The m
Mobile conversion is 40% below desktop. Product blames the design; analytics shows users leaving before the page is usable. How do you investigate?
Get field data before touching anything A laboratory run on a developer machine measures one configuration, usually the fastest one anyone uses. Real traffic in
You are designing APIs for a platform with a web app, a mobile app, internal service-to-service traffic and third-party partners. What do you expose, and where?
What the interviewer is testing Whether you choose per constraint or adopt one technology as an identity. The wrong answers here are all defensible sounding and
You inherit an IoT fleet of 80,000 devices whose client certificates all expire in fourteen months. What do you do?
Establish whether rotation is even possible The first question is whether the current firmware can obtain and install a new certificate remotely. If it cannot,
You migrate a mobile API to HTTP/2 and p99 latency gets worse for users on cellular networks, while p50 improves. Explain and decide what to do.
The mechanism TCP head of line blocking. HTTP/2 multiplexes all streams onto one TCP connection. TCP guarantees ordered delivery, so a single lost packet stalls
After a five-minute network outage at your ingest tier, 200,000 devices reconnect simultaneously and the authentication service collapses. How do you fix this?
The mechanism Every device detected the disconnection at roughly the same moment and retried immediately. Reconnection is the most expensive operation in the fl
An OTA firmware update has bricked 3% of a 50,000-device fleet. What do you do, and what should have prevented it?
Halt immediately, then determine the correlation Stop the rollout before anything else. Then find what the 1,500 have in common: hardware revision, previous fir
You are designing a field-service application for engineers who work in basements and rural sites with no reliable connectivity. What is the architecture, and what are the decisions that will bite later?
The shape: local first, with the server as an eventual replica Connectivity is an optimisation, not a precondition. The application writes to a local store, ren
Edge, Mobile & IoT
General material on architecture beyond the data centre boundary.
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.
Edge Functions
Short-lived compute at the CDN, its runtime limits, and what must stay at origin.
Edge Security & Attestation
Secure boot, hardware roots of trust, and proving what is running on a device.
IoT Ingest Architecture
Millions of small, unreliable, frequently duplicated messages arriving continuously.
Mobile App Architecture
Layering, navigation, background execution, and the platform rules you do not set.
Mobile Release Strategy
Store review, staged rollout, and supporting versions you can never force off.
CRDTs
Data types that converge without coordination, and the semantics you must accept.
Constrained Protocols
MQTT, CoAP and their kin, chosen for power, packet size and intermittent links.
Device Identity
Identifying a thing rather than a person, and rotating a credential you cannot type.
Device Provisioning
Getting identity and configuration onto hardware at manufacture or first boot.
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.
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.
Offline-First
Treating connectivity as an optimisation, with a local store as the source of truth.
Physical-World Failure Modes
Power loss, tampering, clock drift, thermal limits, and a truck through the fibre.
Push & Background Work
Delivery that is best-effort, and an operating system that will kill your process.
Sync & Conflict Resolution
Two devices that both changed the same record while neither could see the other.
Edge Computing
Moving compute towards the user, and what cannot follow it.
Edge Rendering
Running the render close to the user, and the personalisation and cache trade it implies.
Content Delivery Networks
Edge caching, origin offload, spike absorption and dynamic content.
Synthetic Data
Generating data with the shape and edge cases of the real thing, and where it misleads.