Answered here so the briefing can go to your actual constraints. Repository links resolve to the upstream Apache 2.0 source. Architecture references map to public documentation.
Does this replace our Confluent or Apache Kafka cluster?
No. The pattern is explicitly additive. Lascaris sits next to your production cluster as one more read-only consumer and keeps the backup on a parallel stack. Production traffic, ksqlDB, Connect, Stream Governance, and every other feature you rely on continues to work exactly as before. The first deployment can be one mirrored topic in a single namespace; the production team is not required to change a single line of producer code.
How does recovery work?
Lascaris backup is a parallel recovery stack, not in-place rollback of production. The backup on S3 is an immutable, durable copy of every mirrored topic. Standard Kafka consumers read it through the normal wire protocol. Replay, batch reprocessing, failover drills, and agent workloads all run against the stack without touching the source cluster. Topic-level recovery runs on the DR side today: restore a mirrored topic as of a chosen time into a new topic for controlled validation and cutover. The restored topic is additive, not a rollback of the source cluster. Every segment carries its commit timestamp in S3 metadata, which is what makes point-in-time restore possible.
What happens during a long target-cluster outage?
Lascaris does not require a separate disk buffer. The internal franz-go producer has an in-memory buffer with retries for transient interruptions. If the backup target is unavailable for an extended period, the consumer applies backpressure and stops advancing the offset on the source cluster. The source cluster itself acts as the durable buffer through its existing retention. When it returns, replication resumes from the last committed offset, no data lost. This is documented in the Resilience section of the source.
Can this run air-gapped?
Yes. Lascaris runs without internet egress. Container images mirror to your registry. The only requirements are a reachable S3-compatible endpoint (MinIO, Ceph, or on-prem object store) and a reachable etcd ensemble. Both can sit inside your network boundary or inside a classified enclave. The data path makes no external calls.
What is the realistic ingestion ceiling?
A single Lascaris replication job handles up to roughly 250 MB/s sustained with zstd compression and a 50 MB fetch batch. Larger estates run multiple jobs in parallel, partitioned by topic prefix. The backup side scales horizontally with stateless broker pods, and S3 is effectively unbounded for the throughput tier most backup workloads need. The bottleneck is almost always source-cluster egress, not the backup side.
What does Scalytics provide on top of the open source?
Lascaris managed by Scalytics in your own cloud, or support while you run it yourself. Architecture review for backup and DR strategy, hardening for regulated environments, DORA and NIS2 evidence packs mapped to your specific topics and retention, integration with Apache Wayang for federated analytics over the backup data, and 24/7 enterprise support contracts. The repositories remain Apache 2.0. The product roadmap is independent of any specific support engagement.
Will offsets match between source and backup?
For recovery, exact offset preservation across vendors is not the design goal. Lascaris preserves order within a partition, preserves message keys, and uses production to keep duplicates rare. The mirrored topic in the backup has its own offset space, which is the expected behavior for a backup target. If your workload requires offset-preserving replication for active-active or hot failover, that is a different pattern with different tradeoffs and we will say so on the briefing call.
How long does a full pilot take?
Two weeks for a working pilot in a non-production environment, including Lascaris deployment on your Kubernetes, three to five topics mirrored, and one recovery-test report generated. Four to six weeks for a production rollout with compliance evidence aligned to your specific DORA or NIS2 control set. The architecture sprint covers both phases.