Connecting workloads across AWS, Azure, and GCP is technically straightforward in the sense that connectivity options genuinely exist for all three. It's considerably harder in practice, because each platform's networking model works differently under the hood, and a design pattern that works cleanly within one platform doesn't translate directly to the others without real, deliberate adaptation. My position: the biggest risk in multi-cloud networking isn't any single platform's connectivity option failing it's inconsistency in how security and routing get applied across platforms that each have genuinely different native models, creating gaps specifically at the seams between them that a single-platform security review will never catch, because each individual review is only ever looking at one piece of the whole picture. Each Platform's Networking Model Is Genuinely Different, Not Just Differently Named AWS VPCs, Azure Virtual Networks, and GCP VPC networks aren't the same concept wearing different labels they have real structural differences in how peering, routing, and access control actually work. Applying an AWS-flavored mental model directly to Azure or GCP networking design produces subtly incorrect assumptions that don't show up as an obvious error, they show up as a gap nobody notices until it's specifically tested or exploited. GCP's VPC model, for instance, is genuinely global by default in a way AWS's region-scoped VPCs and Azure's region-scoped virtual networks aren't a single GCP VPC can span multiple regions natively, while achieving equivalent multi-region connectivity in AWS or Azure requires explicit peering or transit gateway configuration between region-scoped resources. An engineer who's deeply fluent in AWS networking and applies that same mental model to GCP without accounting for this structural difference will make genuinely incorrect assumptions about how traffic flows and what's actually isolated from what. Connecting the Clouds: VPN, Dedicated Interconnects, and Third-Party Solutions Direct connectivity between cloud providers generally happens through one of a few patterns: VPN connections between each provider's networking infrastructure, dedicated interconnects where providers offer direct peering options, or third-party network-as-a-service platforms specifically built to abstract multi-cloud connectivity into one more unified layer. Each has genuine tradeoffs VPN is simpler and cheaper with more variable performance, dedicated interconnects offer better performance at higher cost and setup complexity, and third-party platforms trade some direct control for genuinely simplified, unified management across all three environments. The right choice here often depends on how much traffic genuinely needs to move between clouds versus staying within a single cloud's boundary. Organizations with a clear primary cloud and genuinely occasional cross-cloud traffic for specific integrations may find VPN entirely sufficient. Organizations running genuinely significant, latency-sensitive workloads split across multiple clouds simultaneously benefit more from dedicated interconnects or a purpose-built multi-cloud networking platform that can manage the complexity centrally rather than requiring each cross-cloud connection to be individually configured and maintained. Security Groups, NSGs, and Firewall Rules Don't Translate Automatically AWS security groups, Azure Network Security Groups, and GCP firewall rules all accomplish conceptually similar things and have genuinely different syntax, default behaviors, and rule evaluation logic. A security policy that's correctly implemented in AWS doesn't automatically transfer to an equally correct implementation in Azure or GCP just because someone applied "the same rule" conceptually each platform's specific implementation needs its own genuine, deliberate configuration, verified independently rather than assumed equivalent. One specific, common gap: AWS security groups are stateful by default, automatically allowing return traffic for an allowed connection, while some equivalent constructs on other platforms require explicit bidirectional rules. An engineer who assumes stateful behavior everywhere, based on AWS experience, can end up with rules that appear correct and actually block legitimate return traffic on a different platform, or worse, leave a gap open that the stateful assumption would have closed automatically on AWS but doesn't actually close on the platform where the rule was actually implemented. DNS Across Multi-Cloud Needs a Genuine Unified Strategy Each cloud provider offers its own DNS services, and without deliberate architecture, DNS resolution across a multi-cloud environment can become genuinely inconsistent different behavior depending on which cloud a request originates from. A unified DNS strategy, whether through a single provider's DNS extended across environments or a genuinely platform-agnostic DNS solution, prevents this specific, common source of confusing, hard-to-diagnose failures. Centralized Visibility Is the Genuine Foundation, and It's Frequently Missing Most organizations running multi-cloud have reasonably good network visibility within each individual platform and genuinely poor unified visibility across all three simultaneously. Building centralized network monitoring and logging that actually aggregates across AWS, Azure, and GCP not three separate dashboards nobody's cross-referencing is foundational to actually managing multi-cloud networking securely, since problems at the seams between platforms are exactly what siloed, per-platform visibility structurally can't catch. This gap tends to be invisible until an incident specifically spans multiple platforms, at which point the team discovers, in real time, that nobody has a single place to correlate what happened across all three environments simultaneously and reconstructing that picture manually, mid-incident, from three separate logging systems with three separate formats, is exactly the kind of delay that turns a contained incident into a considerably longer one. Identity Federation Needs to Extend Genuinely Across All Three Network-level security is only part of the picture genuine identity federation across AWS, Azure, and GCP, rather than separate, platform-native accounts for each, closes a gap that's specifically dangerous in multi-cloud environments, since a user or service with both a federated identity and separate platform-native accounts represents multiple access paths that need independent auditing rather than one coherent, unified one. What Genuinely Secure Multi-Cloud Networking Requires Genuine, platform-specific expertise for each cloud in use, not one platform's model loosely applied to the others, since even seemingly small structural differences produce genuinely incorrect assumptions Deliberate choice of connectivity pattern VPN, dedicated interconnect, or third-party platform matched to actual cross-cloud traffic volume and latency sensitivity Security rules independently verified per platform, not assumed equivalent across genuinely different native models and default behaviors A unified DNS strategy, avoiding platform-dependent resolution inconsistency Centralized, genuinely unified visibility across all three environments, built before an incident forces the gap into view mid-crisis Full identity federation, eliminating the parallel platform-native accounts that undermine unified access auditing The Actual Point Multi-cloud networking risk doesn't concentrate within any single platform each individual cloud's networking, done well, is a mature, solvable problem. The risk concentrates specifically in the inconsistency between platforms, at the boundaries where each provider's genuinely different model meets the others, and that's exactly where a per-platform review, however thorough within its own scope, will never look, because it was never designed to look at the seam in the first place. Vendor Lock-In Concerns Shouldn't Drive Networking Architecture Alone A common motivation for multi-cloud adoption is avoiding dependency on a single provider, and it's worth being honest that multi-cloud networking itself introduces its own form of complexity-driven lock-in once genuine cross-cloud networking architecture is built and operational, unwinding it back to a single-cloud model is its own significant undertaking. This doesn't mean multi-cloud is the wrong choice; it means the decision to go multi-cloud should be driven by genuine business requirements redundancy, specific service capabilities only available on certain platforms, regulatory requirements rather than an abstract preference for avoiding vendor dependency, since the operational complexity cost of multi-cloud networking is real and ongoing, not a one-time setup cost that fades into the background afterward. Cost Visibility Across Multi-Cloud Networking Specifically Data transfer costs between cloud providers are frequently higher than transfer within a single provider's own network, and this cost can accumulate significantly for workloads that weren't specifically designed with cross-cloud data movement in mind. Reviewing actual cross-cloud data transfer patterns and costs regularly, rather than only at the point a surprising bill arrives, catches architecture decisions that are quietly generating more inter-cloud traffic, and more cost, than the original design intended. ArclogiQ | Cloud Solutions, Security, Network & Infrastructure Optimize your cloud spend, achieve absolute regulatory compliance, and build secure, high-performance network environments. arclogiq.com