Database Expert

MySQL expert should take ultimate responsibility for the database, which is a crucial key component of whole Rohlik ecosystem. Creating database strategy, fulfilling database strategy but also daily maintenance (if needed) is expected. 24/7 support of databases is not a part of MySQL expert job description - this burden is on datacenter / cloud provider. This role is almost 100% independent and without joining to classical project planning and software development.

What we expect from you

• Ad-hoc Support to Developers: Providing crucial support with databases, such as creating test replicas and environments, especially during service separations.
• Monitoring Problematic Queries: Keeping an eye on and managing large or long-running queries to prevent system overloads.
• Management of Execution Plans: Addressing the complexities of execution plans across various DBMS, such as MySQL and PostgreSQL.
• Addressing Severe Database Issues: Moving away from the current brute-force approach (e.g., query termination) to more sophisticated solutions.
• Development of Test Databases: Enhancing our capacity to develop and maintain test databases that are critical for continuous integration and delivery pipelines.
• Efficient Generation of Test Databases: Aiming to have test databases for each pipeline generated swiftly, to facilitate timely and effective testing.
• Performing High-risk Migrations: Undertaking complex database migrations that are too risky to perform during peak hours.
• SQLBot Development: Creating and improving automation tools for database management.
• Active Query Tuning: Searching for and tuning problematic queries to optimize database performance.
• Innovative Database Monitoring: Developing advanced monitoring systems to preemptively address potential issues by setting alerts based on query duration and resource consumption.
• Strategic Database Initiatives: Such as the long-term shift from serial IDs and managing the conversion of current databases to ensure scalability.

• Professional in:

• DB management with recent versions of RDBMs like MSSQL, PostgreSQL, Oracle or best MySQL (5.7, 8) - MariaDB
• If candidate has professional knowledge of other than MySQL DB, its expected willingness to quickly learn MySQL
• Understanding and expert level tuning of DB (preferably MySQL’s ) underlying storage engines
• Experience with DB cloud services (preferred GCP & MySQL)
• Debugging and optimisation of SQL statements, execution plans, index / resource planning, locking
• Master / Master and Master / replica clustering experience

As great advantage:

• experience with development of MySQL database engine

A person able to:

• Design database architecture in context of rapidly growing company and customer base
• Problem solver, person able to deliver functional solution
• Be part of decision makers what should be database strategy
• Maintain smooth operation of database
• Apply best practices in maintenance tasks such as migrations, backups, restores, DR etc.
• Plan resource requirements from current load of the databases and high level specifications (upcoming projects) in steady growing company
• Revise / oppose sql updates / requirements coming from developers
• shift Rohlik’s databases to the best possible performance
• properly balance in the cloud / on premise database infrastructure

Nice to have

• Knowledge of latest MySQL features (event scheduler, buffers, hash index, ...) and its practical effects on performance with larger datasets.
• Knowledge of limitations in MySQL and their workarounds in contrast to other (relational) databases
• Knowledge of HA setup of MySQL (HAProxy, keepalived,...) is a plus
• Professional experience and maintenance with databases at least 3 years
• Experience with noSQL databases, preferably MongoDB
• Knowledge of ProxySQL or similar tool
• Familiar with other SQL / NoSQL databases such as PostgreSQL, Cassandra / Couchbase /... etc. is a plus
• Knowledge and understanding of underlying hardware and its limitations

• Your work will have a direct impact on the company's results
• We will implement your good ideas almost immediately – not waiting for the approval of the headquarters somewhere in the world
• You will not be bound by corporate processes
• Your work has to be innovative and meaningful, we do not want to follow trends, but set them
• Last but not least, we mainly offer a fair reward and the possibility of professional growth and education, also a great bunch of people around and legendary corporate events