A global Investment Bank is looking for a hands-on Cassandra Database Engineer to join a major Financial Crime technology programme. This is a key technical role within a high-profile transformation programme, where you’ll help design and build the Cassandra/NoSQL data platform supporting the migration of data from an existing Oracle environment.

Cassandra Database Engineer – Contract | London

Location: London
Working pattern: Ideally 1 day per week in the office
Contract: Contract
Start: September 2026
£600-706 Umbrella

The Opportunity

A global Investment Bank is looking for a hands-on Cassandra Database Engineer to join a major Financial Crime technology programme supporting a significant NICE Actimize IFM upgrade.

This is a key technical role within a high-profile transformation programme, where you’ll help design and build the Cassandra/NoSQL data platform supporting the migration of data from an existing Oracle environment.

You’ll have genuine ownership of the Cassandra architecture and will play a critical role in ensuring the platform is high-performing, resilient and production-ready.

What You’ll Be Doing

• Design and implement Apache Cassandra architecture, including keyspaces, tables, partitioning and replication strategies.
• Develop robust data models aligned to application query and transaction patterns.
• Support the Oracle-to-NoSQL data migration and associated technical design.
• Design for high availability, including active-active architecture, failover and disaster recovery.
• Build, configure and operationalise Cassandra clusters.
• Undertake performance tuning, capacity planning and production readiness activities.
• Manage cluster operations including node additions/decommissions, repairs, backups and recovery.
• Work closely with application, middleware, infrastructure, security and delivery teams.
• Provide technical guidance on CQL and Cassandra best practices.
• Produce technical documentation, operational runbooks and support knowledge transfer.
• Work with internal teams and technology partners to ensure a successful delivery.

What We’re Looking For

The priority is genuine, hands-on Cassandra expertise rather than someone who has simply worked alongside Cassandra.

You should have strong experience with:

• Apache Cassandra in production environments
• Keyspace and table design
• Data modelling and partition-key design
• Replication factors and consistency
• Cassandra architecture and configuration
• Cluster operations and troubleshooting
• Performance tuning and capacity planning
• High availability, failover and disaster recovery
• CQL and Cassandra internals
• Linux administration and scripting

Experience with technologies such as Oracle, Kafka, IBM MQ/IIB or NICE Actimize would be beneficial but is not essential.

No Banking Experience Required

This is a purely technical hire, so candidates from any industry are welcome.

We’re particularly interested in:

• Experienced Cassandra engineers
• NoSQL database specialists
• DBAs who have developed strong Cassandra expertise
• Data engineers who retain deep hands-on Cassandra knowledge
• Engineers from other NoSQL technologies, particularly HBase/wide-column databases

Broader NoSQL experience such as MongoDB may also be considered, although Cassandra experience is strongly preferred due to the immediate requirements of the programme.

The Ideal Candidate

You’re someone who can operate as a technical authority — comfortable getting into the detail of Cassandra architecture while also working collaboratively with developers, infrastructure teams, vendors and senior stakeholders.

Most importantly, you know Cassandra hands-on and can make sound architectural and operational decisions in a production environment.

If you’re an experienced Cassandra Engineer looking for a technically challenging contract where you can make a tangible impact, we’d be interested in speaking with you.

London presence is preferred, with at least one day per week in the office. Some flexibility may be available for exceptional Cassandra specialists, subject to approval.

Robert Walters Operations Limited is an employment business and employment agency and welcomes applications from all candidates