Senior Data Base Administrator

Project: HR SaaS for the public sector. We are looking for a Senior Database Engineer to execute a production database migration from on-premises Microsoft SQL Server to Amazon RDS for a large HR/Learning SaaS platform serving public-sector and government agencies. You will own the migration mechanism end-to-end: moving multiple active OLTP databases with a near-zero-downtime cutover and a verified rollback path. This is a hands-on delivery role embedded in a cross-functional team (Backend, DevOps, and the client's existing DBA and QA teams). Beyond the migration itself, you will diagnose and resolve database-layer issues that surface during parallel run and cutover (latency, connection routing, read-only replica behavior). The platform's longer-term direction includes introducing PostgreSQL alongside SQL Server, so experience with a polyglot estate is a strong plus.

Key Responsibilities:

• Execute the migration of the OLTP database from on-prem SQL Server to Amazon RDS for SQL Server (Multi-AZ)  for dependent products.


• Provision and configure RDS instances (Enterprise Edition for AG support), parameter groups, option groups, backups, and Multi-AZ HA across all environments.


• Validate RDS feature compatibility: Change Tracking (required for downstream ETL) and CLR SAFE assemblies; prepare and cost the fallback path


• Diagnose and fix database-layer issues during parallel run and cutover: Transit Gateway / cross-network latency, connection-string and read-only routing, command timeouts, and accidental writes to read replicas.


• Define and rehearse cutover and rollback runbooks (failover/failback timings, RPO/RTO targets, validation steps); support QA parity testing and performance baselining


• Establish monitoring, alerting, and backup/recovery (CloudWatch, Performance Insights, point-in-time recovery) for the migrated databases.

Tools and skills you will use in this role:

• Microsoft SQL Server (T-SQL, Always-On Availability Groups, Change Tracking, CLR)


• Amazon RDS for SQL Server (Multi-AZ), AWS DMS


• AWS (VPC/Transit Gateway, S3, CloudWatch, Performance Insights, IAM)


• Nice to have: Infrastructure-as-Code (AWS CDK)


• Nice to have: PostgreSQL / Amazon RDS / Aurora PostgreSQL

Requirements:

• 5+ years as a DBA / Database Engineer in production environments.


• Deep Microsoft SQL Server administration expertise: Always-On Availability Groups, replication, backup/restore, log shipping, Change Tracking, performance tuning, and T-SQL.


• Proven experience migrating SQL Server workloads to AWS, ideally Amazon RDS for SQL Server, including AG-based and/or DMS-based approaches.


• Strong understanding of HA/DR, RPO/RTO, cutover, and rollback planning for active production systems.


• Hands-on AWS experience: RDS, networking (VPC, Transit Gateway), S3, monitoring, IAM.


• Ability to troubleshoot database connectivity, latency, and routing issues in hybrid (on-prem + cloud) topologies.


• Experience working alongside a client-side DBA team and coordinating phased, multi-environment rollouts.


• English: Upper-Intermediate or higher.

Nice to have:

• PostgreSQL administration and SQL Server-to-PostgreSQL migration experience (schema, stored procedures, data-type mapping, dual-write/cutover).


• Familiarity with EF Core / Npgsql and .NET application data layers.


• Experience with AWS DMS for heterogeneous migrations.


• Infrastructure-as-Code with AWS CDK; CI/CD-driven database migrations.


• Exposure to regulated/compliance environments (e.g. FedRAMP).

We offer*:

• Flexible working format - remote, office-based or flexible


• A competitive salary and good compensation package


• Personalized career growth


• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)


• Active tech communities with regular knowledge sharing


• Education reimbursement


• Memorable anniversary presents


• Corporate events and team buildings


• Other location-specific benefits

*not applicable for freelancers