Lead ClickHouse Engineer

Lead ClickHouse Engineer

Remote (UK-based) | Full-Time

About Us

Reactive Markets is the 2026 OTC Trading Platform of the Year ( Risk.net ). Our network handles over $50 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 40+ of the world's leading liquidity providers.

We build trading systems that operate at the edge of what's technically possible — where nanoseconds matter and a dropped message costs real money. Our engineering team is small, senior, and deeply invested in the craft of building cutting edge, reliable, high-performance systems.

The Role

We're looking for a Lead ClickHouse Engineer to own our data plant: a multi-datacentre, multi-AZ ClickHouse cluster ingesting billions of rows a day, underpinning compliance, billing, and a growing family of real-time and historical analytics.

This is a core-platform engineering role, not a DBA role. You'll own the full engineering scope of a serious ClickHouse estate: cluster operations and upgrades, schema and sorting-key design, materialised views, ingestion performance, query optimisation, workload isolation, capacity planning, storage tiering, backup and recovery, monitoring and alerting, and production support. You'll also set direction and work on the data pipelines around the plant — our capture services are Go, and our analytics foundation is Python.

Beyond your own technical ownership, you'll set the standard for how the estate is run, mentor the engineers who work alongside you, and ensure the plant is genuinely supportable by a team rather than dependent on any one person — including yourself.

You don't need years of ClickHouse specifically — deep experience with another columnar or large-scale time-series database qualifies you, and a strong columnar engineer learns our estate quickly. What we do need is genuine operational depth: you have run a production data platform, owned its capacity plan and its recovery procedures, and stayed calm when it mattered.

This hire helps create a follow-the-sun team — so the platform is supported across time zones rather than by heroics. On-call is a shared, contracted responsibility, planned and paid — not goodwill.

What You'll Work On

Cluster operations at scale — running, upgrading and evolving a multi-AZ ClickHouse estate on Kubernetes, with rehearsed backup and recovery

Schema and query engineering — table and sorting-key design, partitioning, materialised views, and query optimisation against multi-terabyte datasets

Capacity and observability — a measured capacity model, storage tiering and retention, and the Grafana monitoring and alerting that keeps the plant's health visible

Ingestion and data quality — correctness and completeness gates on the pipelines feeding the plant; reconciliation that proves nothing was dropped

Workload isolation — keeping ingest, operations, reporting and ad-hoc analytics from treading on each other as read load grows

Team and knowledge leadership — mentoring the engineer(s) working on the estate, setting standards for runbooks and documentation, and making the plant supportable by the team, not the author

AI-assisted operations — modern tooling (including MCP-based AI access to the estate) that lets a small team run a large platform well

What We Need

Technical:

Columnar/OLAP database engineering — ClickHouse strongly preferred; deep experience with another columnar or large-scale time-series store (BigQuery, Redshift, Druid, kdb+ or similar) also works

A track record of owning architectural decisions for a production data platform, not just operating within one someone else designed

SQL depth — execution plans, query optimisation, and schema design for very large datasets