I am working as Performance engineer, my major focus is end-to-end performance testing/engineer activities. 1. Identifying the key transactions and scripting 2. execution of baseline , scalability, load, stress, volume & soak testing ... 3. Analysis of the test results and servers stats. 4. Providing the root cause of the problems and recommendations. 5. Re-testing after the fixes are done. 6. Capacity planning 7. Sizing recommendations 8. Network bandwidths recommendations 9. Analyze the sizing calculators for small medium and large datasets.