Meta · 2026
2026 World Cup: Breaking Records, Spiky Charts and Reliability at Scale
How Meta absorbed the 2026 World Cup, when WhatsApp set a record of more than 30 million messages per second during the final. Pre-provisioned capacity buffers were the most effective lever, alongside country-level shedding of non-critical load, load-testing and resizing 100+ services, forecasting each region's peak separately, and no deploy freeze.
30 million+ WhatsApp messages/sec8.4 billion messages in 5 minutescapacity planningload testingload sheddingTaijiKatranProxygen
PlanetScale · 2026
Designing a planned switchover for minimum disruption
When a Neki shard's primary has to step aside for a pod replacement, kernel upgrade or cell move, PlanetScale does a planned switchover instead of stopping Postgres the way Patroni does, so a failed switchover can quickly fall back to the old primary. Admin, Neki's control plane, first validates shard state, the target replica, logical failover slots and Postgres settings. Routers then proactively buffer primary-bound queries, the primary defaults new transactions to read-only, and the other replicas are disconnected to pin a final WAL position the target must replay. If the target can't catch up before a deadline, a config reload makes the old primary writable again. Buffered queries are replanned against the new primary, so apps see added latency instead of errors, and every acknowledged commit is on the target when it is promoted.
one primary and multiple replicas per shardsynchronous replication ANY 1 across eligible replicasplanned switchoverquery bufferingsynchronous replicationPostgreSQLNekiKubernetes
Netflix · 2026
Single-tenant Titus: VM-level isolation on a multi-tenant container platform
Titus, Netflix's Kubernetes-based container platform, launches millions of containers a week on tens of thousands of EC2 instances, packing many teams onto shared hosts. cgroups can't fence last-level cache, memory bandwidth or the global lock in HTB network shaping, so a small-packet flood from one container could starve its neighbors, and stateful streaming jobs like Flink would fall behind and need minutes to catch up. After ruling out microVMs (Firecracker, Kata), gVisor and moving teams to plain EC2, Netflix added an allowlisted single-tenant mode: the federation layer tags eligible tasks, the autoscaler launches the smallest instance that fits each one just in time, and anti-affinity, taints, no preemption and no repacking keep it alone on its host, all behind the same Titus API. Flink, streaming connectors and telemetry pipelines now report stable operation, and the shared fleet packs more densely because sensitive workloads no longer need anti-affinity spreading. The cost is slower launches, since every task waits for its own instance, and fixed host overhead that can take tens of percent of a small node.
millions of containers launched per weektens of thousands of EC2 instances across multiple AWS regionsworkload isolationmulti-tenancyautoscalingTitusKubernetesAWS EC2
Zalando · 2026
From Homegrown to Flink: Migrating a Stateful Ad Event Join at Scale
Zalando Marketing Services replaced a 7-year-old homegrown in-memory join that matched Sponsored Products auction bids to clicks/views within 15 minutes. The old Java service read up to 200 MB/s, could not partition both streams cleanly, and lost up to 15 minutes of state on every deploy or rescale. After Interval Join burned 15-30% CPU on RocksDB seeks and held a ~70M-entry timer queue, they rewrote the match with KeyedCoProcessFunction (point lookups, RocksDB TTL expiry), incremental 3-minute checkpoints, and two-way state. A four-week shadow pipeline hit 99.9% enrichment parity, then a one-week A/B test; average pods fell from 20 to about 5, memory from ~320 GB to ~100 GB, and EC2 cost from about €80 to €30 per day, with enrichment up ~0.5%.
up to 200 MB/s on the old pipelineaverage pods cut from a constant 20 to ~5 (range 1-8)stream joinscheckpointingkeyed stateApache FlinkRocksDBKubernetes