Karel Sague
- 8+ years as a Software Engineer at Square (Block)
- 7+ years as a Software Consultant at ThoughtWorks
- Real-time data infrastructure: Kafka, Flink, Iceberg
In short
Karel Sague is a Staff Software Engineer at Factor House, working on real-time data streaming infrastructure spanning Apache Kafka, Apache Flink, and Apache Iceberg, after eight years as a Software Engineer at Square (Block).
Karel Sague is a Staff Software Engineer at Factor House, where he works on real-time data streaming infrastructure spanning Apache Kafka, Apache Flink, and Apache Iceberg. He joined Factor House after close to nine years as a Software Engineer at Square (Block), and before that spent over seven years as a Software Consultant at ThoughtWorks. Across his career he has built and operated large-scale data platforms in financial services and consulting, with deep experience in event-driven architecture, streaming ingestion, and open table formats.
Expertise
Karel's expertise spans event-driven architecture, streaming ingestion, and open table formats. He has hands-on production experience migrating data platforms from proprietary warehouses onto Apache Iceberg, and streaming Kafka into a lakehouse using Kafka Connect. He also works on Kafka cluster consolidation and migration strategy, including service tiering, cost and operational-risk tradeoffs, offset preservation, and mirroring approaches such as MirrorMaker 2.
Experience
Karel is currently a Staff Software Engineer at Factor House, which he joined in 2026. Before that, he spent close to nine years as a Software Engineer at Square (Block), and briefly worked as a Software Engineer at Simple Machines Pty Ltd on data engineering and data-driven products. Earlier in his career, he spent over seven years as a Software Consultant at ThoughtWorks, and worked as a Software Engineer at Majitek.
Education
- Bachelor's degree, Computer Science, University of Havana
Talks, appearances and mentions
Work published, hosted or co-presented by someone other than Factor House.
- Talk July 8, 2024 · Programmable 2024
Riding the Streams
co-presented with Rashmi Shamsundar, while at Cash App (Square/Block)
How Cash App enabled self-serve streaming applications on Apache Flink and Ververica after migrating from a monolith to an event-streaming architecture, covering infrastructure automation, operations, and lessons from running Flink in production at scale.
Karel also posts on LinkedIn.
Talks
Kafka Reduce Kafka spend and operational risk: practical techniques for cluster consolidation
In this recorded webinar, Karel Sague and Chad Harris from Factor House share a practical framework for cutting Kafka costs and operational risk through cluster consolidation and migration.
August 27, 2026
Iceberg Journey to an open lakehouse with Iceberg
Karel Sague, Staff Software Engineer at Factor House, shares real-world lessons migrating a production data platform from Snowflake to Apache Iceberg, streaming Kafka into Iceberg with Kafka Connect.
August 14, 2026Latest articles
Apache Iceberg: the complete guide
Apache Iceberg is an open table format bringing ACID transactions, schema evolution, and time travel to huge analytic tables in S3. This hub indexes what we've written about running it in production.
September 6, 2026Iceberg use cases
Companies running Apache Iceberg in production, the architectures behind their deployments, and what to read next. Indexed as we publish new use-case research.
September 6, 2026How Airbnb uses Apache Iceberg in production
How Airbnb moved its Kafka-fed warehouse ingestion pipeline off Tez and Hive onto Spark 3 and Apache Iceberg, consolidating tables via partition-spec evolution and cutting compute by over 50%.
September 6, 2026How Apple uses Apache Iceberg in production
How Apple built GDPR- and DMA-compliant row-level deletes on Iceberg tables holding tens of petabytes of data, sourced from a peer-reviewed paper by eight Apple engineers and named conference talks.
September 6, 2026How LinkedIn uses Apache Iceberg in production
How LinkedIn's OpenHouse control plane governs 300,000+ Apache Iceberg tables holding over an exabyte of data, with automated compaction and cross-region replication.
September 6, 2026How Netflix uses Apache Iceberg in production
How Netflix moved its S3 data warehouse off Hive onto an Iceberg-only architecture, and how Maestro, Psyberg, and its Cassandra engine lean on Iceberg's own snapshot and partition metadata.
September 6, 2026How Pinterest uses Apache Iceberg in production
How Pinterest rebuilt CDC ingestion and ML feature backfills on Apache Iceberg, cutting pipeline latency from 24+ hours to minutes and backfill time from 140 days to 26.
September 6, 2026AKHQ vs Confluent Control Center
AKHQ is free and runs against any Kafka. Confluent Control Center is not sold separately and needs Confluent Platform in the brokers. What each costs.
August 30, 2026AKHQ vs Kadeck
AKHQ is free under Apache 2.0 with no paid tier. Kadeck sells governance at ten seats. What each costs, where each runs out, and which fits which team.
August 30, 2026AKHQ vs Kafbat UI
AKHQ and Kafbat UI are both free and Apache 2.0, so the split is maintenance and governance. What each masks, what each audits, where each runs out.
August 30, 2026AKHQ vs Kafdrop
AKHQ and Kafdrop are both free Kafka UIs under Apache 2.0. What each keeps up with, what free actually costs a team, and which one fits which job.
August 30, 2026AKHQ vs Lenses
AKHQ is free with no vendor behind it. Lenses prices by tier and needs a Postgres per component. What each costs to run, where each runs out, and which fits.
August 30, 2026AKHQ vs Offset Explorer
AKHQ is free and deployed once for a whole team. Offset Explorer is licensed per named user and installed per machine. What each costs and where each runs out.
August 30, 2026AKHQ vs Redpanda Console
AKHQ holds nothing back from its Apache 2.0 release. Redpanda Console gives away the viewer and charges for the login. What each costs, and which fits.
August 30, 2026CMAK vs Conduktor
CMAK is free and stopped shipping in 2022. Conduktor bills per seat and needs PostgreSQL. What each costs, where each runs out, and which one fits your team.
August 30, 2026CMAK vs Confluent Control Center
CMAK needs ZooKeeper. Confluent Control Center needs Confluent Platform. What each one costs to run, where each runs out, and which fits which team.
August 30, 2026CMAK vs Kadeck
CMAK is free and needs a ZooKeeper. Kadeck is commercial and bills per user. What each one costs, which clusters each can reach, and which fits which team.
August 30, 2026CMAK vs Kafbat UI
CMAK needs ZooKeeper, so it cannot reach a Kafka 4.x cluster. Kafbat UI connects like any client. What each free tool really costs, and where each runs out.
August 30, 2026CMAK vs Kafdrop
CMAK is an admin console that needs ZooKeeper. Kafdrop is a message viewer that does not. What each is for, what free costs, and what a KRaft cutover breaks.
August 30, 2026CMAK vs Lenses
CMAK is free and stopped shipping in 2022. Lenses is a control plane with a database per cluster. What each costs, where each runs out, and which fits.
August 30, 2026CMAK vs Offset Explorer
CMAK is a server-side console with a hard ZooKeeper dependency. Offset Explorer is a desktop client licensed per user. What each costs and where each runs out.
August 30, 2026CMAK vs Redpanda Console
CMAK cannot reach a KRaft cluster. Redpanda Console licenses the partition reassignment CMAK did for nothing. What each covers free, and which fits your team.
August 30, 2026Conduktor vs Confluent Control Center
Conduktor bills per seat and runs against any Kafka distribution. Confluent Control Center is bundled with Confluent Platform and reaches nothing else.
August 30, 2026Conduktor vs Kadeck
Conduktor sells policy enforcement, Kadeck sells data exploration. What each charges per person, where governance sits on each ladder, and which fits a team.
August 30, 2026Conduktor vs Kafbat UI
Conduktor Console Community caps at 50 users and 3 clusters. Kafbat UI caps at nothing. What each free tier reaches, what the next rung costs, which to pick.
August 30, 2026Conduktor vs Kafdrop
Kafdrop is free with no authentication at all. Conduktor Team Edition is 1,200 US dollars per seat per year. What each free tier reaches, and which fits yours.
August 30, 2026Conduktor vs Lenses
Conduktor bills per seat and puts a proxy on the wire. Lenses tiers by user count and connects as a client. What each costs, and which fits a team.
August 30, 2026Conduktor vs Redpanda Console
Conduktor bills per seat. Redpanda Console is free, with RBAC behind a broker vendor licence. What each costs, where each runs out, and which fits your team.
August 30, 2026Confluent Control Center vs Kadeck
Confluent Control Center ships with Confluent Platform and watches nothing else. Kadeck bills per seat. What each costs, where each runs out, and which fits.
August 30, 2026Confluent Control Center vs Kafbat UI
Confluent Control Center only ever watches Confluent Platform. Kafbat UI is free and reaches any cluster. What each costs, where each runs out, and which fits.
August 30, 2026Confluent Control Center vs Kafdrop
Confluent Control Center needs a broker-side reporter and a platform licence. Kafdrop runs on any Kafka and has no login. What each one obliges you to own.
August 30, 2026Confluent Control Center vs Lenses
Confluent Control Center needs a broker-side reporter and reaches only Confluent Platform. Lenses connects to any Kafka and bills per user. What each costs.
August 30, 2026Confluent Control Center vs Offset Explorer
Control Center ships with Confluent Platform and reaches nothing else. Offset Explorer is a per-user desktop app. What each costs, and which one fits you.
August 30, 2026Confluent Control Center vs Redpanda Console
Control Center only runs on Confluent Platform. Redpanda Console is free until governance. What each costs, where each runs out, and which to pick.
August 30, 2026Kadeck vs Kafbat UI
Kadeck bills per user and puts governance behind Enterprise. Kafbat UI is Apache-2.0 with RBAC, masking, and audit built in. What each costs, and which fits.
August 30, 2026Kadeck vs Kafdrop
Kafdrop is free with nobody to escalate to. Kadeck bills per user and its governed tier starts at ten seats. What each costs, and which fits which team.
August 30, 2026Kadeck vs Lenses
Lenses meters users and capability tiers. Kadeck meters seats. What governance costs on each side, what each one makes you deploy, and which fits your team.
August 30, 2026Kadeck vs Offset Explorer
Kadeck bills per user and puts governance behind a ten-user floor. Offset Explorer is a per-user purchase nobody logs in to. What each costs, and which fits.
August 30, 2026Kadeck vs Redpanda Console
Kadeck bills per user and holds governance at Enterprise. Redpanda Console is free and gates the login. What each costs, where each runs out, and which fits.
August 30, 2026Kafbat UI vs Kafdrop
Kafdrop is a fast viewer with no authentication and no KRaft support. Kafbat UI adds RBAC, masking, and an audit log. What each costs, and which to pick.
August 30, 2026Kafbat UI vs Lenses
Kafbat UI is free and stateless, with no database. Lenses meters by user count from 4,000 US dollars a year. What each costs, and where each runs out.
August 30, 2026Kafbat UI vs Offset Explorer
Kafbat UI is free and deployed once for a team. Offset Explorer is licensed per named user. What each costs, where each runs out, and which fits which team.
August 30, 2026Kafbat UI vs Redpanda Console
Kafbat UI is Apache 2.0 with governance included. Redpanda Console gates access control behind a Redpanda licence. What each costs, where each runs out.
August 30, 2026Kafdrop vs Lenses.io
Kafdrop is a free viewer with no login in front of it. Lenses bills by user count and needs PostgreSQL. What each costs, where each runs out, who picks which.
August 30, 2026Kafdrop vs Offset Explorer
Kafdrop is free with no login in front of it. Offset Explorer is a purchase per named user. What each costs, where each runs out, and which fits which team.
August 30, 2026Kafdrop vs Redpanda Console
Kafdrop is Apache 2.0 with no paid tier. Redpanda Console is source-available, with SSO and RBAC licensed. What each costs, and which fits which team.
August 30, 2026Lenses vs Offset Explorer
Offset Explorer is a desktop purchase per named user. Lenses is a control plane billed by tier. What each costs, where each runs out, and who should pick which.
August 30, 2026AKHQ vs CMAK
AKHQ ships releases. CMAK last shipped in April 2022 and still needs ZooKeeper. What each one costs to carry, where each runs out, and which to pick.
August 29, 2026Conduktor vs Offset Explorer
Conduktor is a per-seat platform with a database behind it. Offset Explorer is a per-user desktop application. What each costs, and which fits which team.
August 29, 2026