Senior Database Administrator (Freelancer)

Job description

Mactores is the agent-native AWS modernization firm. Most modernization work doesn't ship, it stalls in pilots, slips a year, or lands at three times the budget. We exist to ship it: production systems running, legacy retired, outcomes measured. Our delivery is built on Aedeon, the agent platform built by Mactores' founders' sister company, which absorbs the repetitive 60–70% of engagement work, discovery, dependency mapping, validation, test generation, that traditional consulting bills human hours against. Forward-deployed engineers own the rest: architecture, judgment, and cutover, on dates we commit to in the contract. Oracle-to-PostgreSQL migrations don't fail at conversion. They fail at go-live DMS latency nobody diagnosed, autovacuum behavior nobody tuned, privilege mappings nobody tested, incidents nobody owns at 2 a.m. This role sits inside our Application & Database Modernization pillar and exists to make sure that doesn't happen. As our Senior Database Administrator, you'll run the Amazon Aurora PostgreSQL environments in an active Oracle-to-PostgreSQL migration program from cluster design through DMS replication through post–go-live stabilization. Aedeon handles the repeatable conversion and validation work; you own what agents can't: production judgment. When replication lags, when a workload misbehaves after cutover, when an incident escalates past L2, you're the person who resolves it and can explain why it happened. This is a freelance engagement, remote, working as the L3 escalation point on production systems that real businesses run on. ### What you will do? - Design, set up, configure, and manage Amazon Aurora PostgreSQL clusters. - Configure parameters, maintenance windows, monitoring, and scaling strategies. - Keep the environments highly available, fault tolerant, and operationally ready — before go-live, not after. - Map users, roles, and privileges from Oracle to PostgreSQL. - Implement least-privilege access, role hierarchies, and security best practices, and support audit and compliance requirements. - Configure, run, monitor, and optimize AWS DMS tasks (Full Load and CDC). - Troubleshoot DMS latency, data mismatches, and performance issues, and tune DMS settings for large-volume, high-throughput workloads. - Tune server and database performance — CPU, memory, I/O, connections — plus PostgreSQL parameters, autovacuum, indexing, and query behavior. - Find performance bottlenecks before the customer does, and resolve them. - Design and implement backup and restore strategies; define and test DR and failover procedures; support cross-region replication and recovery drills. - Lead post–go-live stabilization: monitor production workloads, resolve incidents, and act as the L3 escalation point for database-related production issues. - Deliver operational documentation and handover support, so what you stabilized stays stable after you. ### What are we looking for? - 5+ years of experience administering Amazon Aurora PostgreSQL. - Proven expertise supporting Oracle-to-PostgreSQL migrations. - Hands-on experience with AWS DMS. - Advanced PostgreSQL performance tuning and troubleshooting skills. - Strong knowledge of backup, restore, and DR planning in AWS. - Experience with AWS monitoring tools (CloudWatch, Performance Insights). - Strong problem-solving and root-cause analysis abilities. - Experience working in production and post–go-live environments. - The ability to work independently as an L3 escalation engineer. - Clear communication and documentation skills. ### You will be preferred if - Familiarity with automation and configuration management tools, such as Ansible, Chef, or Puppet - Familiarity with IAAC tools such as Terraform, CloudFormation - Familiarity with CI/CD implementation tools like Liquibase/Flyway - AWS Certified Database – Specialty - AWS Certified Solutions Architect ### How we work? We refactor legacy databases to cloud-native AWS on a committed date, with Mactores carrying delivery overage risk for delays we cause. Aedeon absorbs the repetitive majority schema conversion, test generation, regression harnesses. Engineers absorb the judgment: risk tradeoffs, production cutover, post-cutover optimization. You're the judgment layer for this program's production environments. When we tell a customer their database will be stable on a date, your work is what makes that sentence true.