Senior Database Engineer at Heirs Holdings

The Role

• As a Senior Database Engineer, you will design, build, and operate the data infrastructure that sits at the heart of this platform. You will own both the relational and distributed NoSQL database layers — ensuring they are highly available, performant, secure, and built to scale to hundreds of millions of users without architectural rework. On a financial platform where data integrity, availability, and compliance are non-negotiable, the database layer is one of the most critical surfaces on the platform — and you own it.

What You'll Do

• Database Engineering & Design — Own the design, provisioning, and ongoing engineering of the platform's database infrastructure across both relational and distributed NoSQL layers — spanning PostgreSQL and Apache Cassandra deployments on AWS and Azure. Translate platform data requirements into robust, scalable, and well-structured data models that support high-throughput transactional workloads, event-driven patterns, and long-term data growth without requiring fundamental rework.
• Relational Database Engineering — Own the platform's PostgreSQL deployments across Azure Database for PostgreSQL and Amazon RDS/Aurora — including schema design, indexing strategies, query optimisation, table partitioning, and replication configuration. Ensure every relational data model is clean, normalised where appropriate, and designed to perform under the load of millions of concurrent users.
• Distributed & NoSQL Engineering — Own the platform's Apache Cassandra deployments across Azure Managed Instance for Apache Cassandra and Amazon Keyspaces — including data modelling, partition key design, consistency level configuration, compaction strategy tuning, and cluster management. Design for write-heavy, high-throughput workloads and ensure partition strategies are fit for the platform's access patterns at scale.
• High Availability & Disaster Recovery — Design and maintain highly available database configurations across both clouds — including replication, automated failover, cross-region redundancy, and backup and recovery pipelines. Define and enforce RTO and RPO targets for all database services. Ensure that no single database failure can cause data loss or platform downtime, and that recovery from any failure is fast, tested, and well-documented.
• Cross-Cloud Data Replication & Active-Active Architecture — Design, implement, and continuously validate real-time data replication between the platform's AWS and Azure database environments — across both PostgreSQL and Apache Cassandra — targeting an active-active configuration where both clouds can serve live traffic simultaneously. Where active-active introduces unacceptable complexity, ensure active-passive replication is consistent enough that failover to the standby cloud is seamless, with near-zero data loss and near-zero transaction gap. Own the replication testing programme — including regular automated failover drills — so that cross-cloud recovery is proven, not assumed, at all times.
• Performance Engineering — Own database performance end to end — from schema design to query execution. Conduct regular slow query analysis, execution plan reviews, and index audits. Tune connection pooling, caching configurations, and database parameters to sustain platform performance as user load grows. Proactively identify and resolve performance bottlenecks before they reach production.
• Database Security & Compliance — Enforce database security standards across all environments — including AES-256 encryption at rest, TLS 1.2+ in transit, IAM-based access controls, least-privilege database user permissions, and audit logging for all privileged access and data modifications. Ensure all database configurations meet PCI DSS and CBN compliance requirements. No database credential is ever hardcoded or stored outside an approved secrets management platform.
• Database as Code — Provision and manage all database infrastructure — including instances, configurations, replication settings, and network connectivity — through version-controlled Infrastructure as Code using Terraform, Ansible, and Bash. No database environment may be provisioned or modified manually. All database configuration must be reproducible, auditable, and deployable on demand through automated pipelines.
• Migration & Schema Change Management — Design and execute zero-downtime database migrations and backward-compatible schema changes — ensuring no migration ever causes a production outage or data inconsistency. Own the migration tooling and process, integrate schema change workflows into CI/CD pipelines, and ensure every migration is tested, reversible, and reviewed before it reaches production.
• Observability & Monitoring — Instrument all database layers with the metrics, alerting, and logging needed to provide complete visibility into database health, performance, and access patterns at all times. Ensure database telemetry feeds into the platform's centralised observability stack — with alerting tuned for replication lag, slow queries, connection exhaustion, lock contention, and unexpected access patterns.
• Developer Enablement — Partner with application engineering teams to establish and enforce data modelling standards, query design guidelines, ORM best practices, and migration conventions across the platform. Review data model proposals from product and engineering teams and provide expert guidance that keeps the database layer clean, performant, and consistent as the platform evolves.

What We're Looking For

Must Have

• 5+ years of hands-on database engineering experience in a production, cloud-native environment — with a track record of owning database infrastructure at scale.
• Expert-level PostgreSQL experience — schema design, advanced indexing, query optimisation, table partitioning, replication, and performance tuning under high-concurrency workloads.
• Strong Apache Cassandra experience — data modelling, partition key design, consistency level configuration, compaction tuning, and cluster operations.
• Hands-on experience with cloud-managed database services — Azure Database for PostgreSQL, Amazon RDS/Aurora, Azure Managed Instance for Apache Cassandra, and/or Amazon Keyspaces.
• Solid understanding of database security — encryption at rest and in transit, IAM-based access controls, audit logging, and compliance requirements in regulated environments.
• Experience provisioning and managing database infrastructure as code — Terraform, Ansible, and Bash — with a clear understanding that no database environment is ever provisioned manually.
• Proven experience designing and executing zero-downtime database migrations and backward-compatible schema changes in live production environments.

Nice to Have

• Experience with Redis for caching — configuration, eviction policies, cluster mode, and integration with application services.
• Familiarity with event-driven architecture patterns — including event sourcing, CQRS, and the data modelling considerations they introduce.
• Experience in fintech, banking, or a regulated data environment — with working knowledge of PCI DSS data requirements or CBN guidelines.
• AWS and/or Microsoft Azure database certifications.
• Experience with database observability tooling — slow query analysis, execution plan visualisation, and replication monitoring at scale.
• Familiarity with data residency and cross-border data transfer requirements across African markets.