Senior Database Administrator (Freelancer)

Mactores is a trusted leader among businesses in providing modern data platform solutions. Since 2008, Mactores have been enabling businesses to accelerate their value through automation by providing End-to-End Data Solutions that are automated, agile, and secure. We collaborate with customers to strategize, navigate, and accelerate an ideal path forward with a digital transformation via assessments, migration, or modernization. We are looking for an experienced Senior Database Administrator to lead and support Amazon Aurora PostgreSQL environments as part of an Oracle to PostgreSQL migration program. The role requires deep hands-on expertise in database administration, AWS DMS, performance tuning, security, and post–go-live stabilization in production environments. What you will do? Design, set up, configure, and manage Amazon Aurora PostgreSQL clusters. Configure parameters, maintenance windows, monitoring, and scaling strategies. Ensure high availability, fault tolerance, and operational readiness. Perform user, role, and privilege mapping from Oracle to PostgreSQL. Implement least-privilege access, role hierarchies, and security best practices. 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. Tune DMS settings for large-volume and high-throughput workloads. Perform server and database performance tuning (CPU, memory, I/O, connections). Tune PostgreSQL parameters, autovacuum, indexing, and query behavior. Proactively identify and resolve performance bottlenecks. Design and implement backup and restore strategies. Define and test disaster recovery (DR) and failover procedures. Support cross-region replication and recovery drills. Lead post–go-live stabilization activities. Monitor production workloads and resolve incidents. Act as L3 escalation point for database-related production issues. Provide operational documentation and handover support. What are we looking for? 5+ years of experience administering Amazon Aurora PostgreSQL Proven expertise in Oracle to PostgreSQL migration support 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 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 Life at Mactores We care about creating a culture that makes a real difference in the lives of every Mactorian. Our 10 Core Leadership Principles that honor Decision-making, Leadership, Collaboration, and Curiosity drive how we work. 1. Be one step ahead 2. Deliver the best 3. Be bold 4. Pay attention to the detail 5. Enjoy the challenge 6. Be curious and take action 7. Take leadership 8. Own it 9. Deliver value 10. Be collaborative We would like you to read more details about the work culture on https://mactores.com/careers The Path to Joining the Mactores Team At Mactores, our recruitment process is structured around three distinct stages: Pre-Employment Assessment: You will be invited to participate in a series of pre-employment evaluations to assess your technical proficiency and suitability for the role. Managerial Interview: The hiring manager will engage with you in multiple discussions, lasting anywhere from 30 minutes to an hour, to assess your technical skills, hands-on experience, leadership potential, and communication abilities. HR Discussion: During this 30-minute session, you'll have the opportunity to discuss the offer and next steps with a member of the HR team. At Mactores, we are committed to providing equal opportunities in all of our employment practices, and we do not discriminate based on race, religion, gender, national origin, age, disability, marital status, military status, genetic information, or any other category protected by federal, state, and local laws. This policy extends to all aspects of the employment relationship, including recruitment, compensation, promotions, transfers, disciplinary action, layoff, training, and social and recreational programs. All employment decisions will be made in compliance with these principles. Note: Please answer as many questions as possible with this application to accelerate the hiring process.