Senior Database Administrator (MongoDB & PostgreSQL)

Role Summary We are seeking a highly experienced Senior Database Administrator with deep, hands on expertise across both MongoDB and PostgreSQL platforms. The successful candidate will own database reliability, performance, security, and scalability across mission critical production environments, taking full responsibility for administration, architecture decisions, high availability design, and disaster recovery readiness. This is a dual platform role requiring genuine depth in both NoSQL and relational database ecosystems, not surface level familiarity in one propped up by the other. Key Responsibilities MongoDB Administer, monitor, and maintain MongoDB environments across development, staging, and production Design and manage replica sets and sharded cluster topologies for high availability and horizontal scalability Own backup and restore strategy, including point in time recovery, and validate recovery procedures regularly Plan and execute database patching and version upgrades with minimal downtime Administer and operate MongoDB Ops Manager for fleet monitoring, automation, and backup orchestration Diagnose and resolve replication lag, shard balancing issues, and index inefficiencies Own internals level troubleshooting including WiredTiger storage engine behaviour, oplog sizing, and write concern tuning PostgreSQL Administer PostgreSQL instances across the full lifecycle, from provisioning to decommissioning Design and implement high availability and clustering solutions (e.g. streaming replication, Patroni, Pgpool, or equivalent) Configure and manage monitoring tooling to proactively identify performance degradation and capacity risks Own backup and restore strategy including physical and logical backups, WAL archiving, and point in time recovery Execute patching and major/minor version upgrades with a tested rollback plan Write and optimize SQL and PL/pgSQL for performance tuning, troubleshooting, and support of application teams Cross Platform Responsibilities Own database patching and upgrade governance across both platforms, including testing, rollback planning, and change management alignment Implement and maintain database auditing, logging, and security hardening practices in line with compliance requirements Lead performance tuning and diagnostics work, including query optimization, index strategy, resource contention analysis, and capacity planning Plan and execute database migrations (version upgrades, platform migrations, cloud/on prem transitions) with minimal business disruption Maintain infrastructure as code and automation for database provisioning and configuration using tools such as Ansible, Jenkins, or Terraform Write and maintain operational scripts and tooling in Bash and/or Python to reduce manual effort and improve reliability Operate within Agile delivery practices, participating in sprint planning, incident retrospectives, and cross functional ceremonies Administer databases on Unix/Linux operating systems, including OS level performance and resource troubleshooting relevant to database workloads Requirements 7+ years in database administration, including 4+ years of hands on production experience across both MongoDB and PostgreSQL. Excellent knowledge of MongoDB and PostgreSQL architecture, internals, HA, and backup/restore. Good knowledge of SQL/PL/pgSQL, Unix/Linux, Agile practices, automation tooling, and scripting. Track record of leading HA/DR design and major version upgrades independently, not just executing existing runbooks. Relevant certifications (MongoDB DBA Associate/Professional, PostgreSQL/EDB/PGCA, or cloud database certifications) are a plus.