Benchmark and profile every single change

In this talk, Daisuke Aritomo discusses the importance of profiling and benchmarking in software development, particularly in the context of Ruby on Rails applications. The main focus is on a method called Benchmark Driven Development (BDD), which involves creating benchmarks before writing the actual code, allowing developers to streamline performance optimization effectively.

Key Points Discussed:
- Introduction to Profiler Updates: Aritomo shares updates on his Ruby profiler, which has reduced memory consumption by 90% and has new features for comparing profiles. He emphasizes that while profilers help in identifying performance issues, they do not automatically make applications faster.

Benchmark Driven Development (BDD): He elaborates on the BDD process, comparing it to Test Driven Development (TDD), wherein benchmarks are created first to define expected performance outcomes.
Real-world Application: Aritomo applies BDD in developing a new web framework called Zinatra, designed for efficiency and speed. By following this methodology, the framework reportedly achieves a performance improvement whereby routing logic is claimed to be up to 100 times faster than traditional implementations, though real-world applications showed that it typically results in around 2% improvements on the actual app performance.
Importance of Continuous Benchmarking: He advocates for continuous benchmarking throughout the coding process, suggesting that every change should be benchmarked to understand its impact on performance effectively.
Tools for Benchmarking: Aritomo presents various tools and frameworks developed to support benchmarking within the coding workflow, emphasizing that realistic workloads and meaningful metrics are crucial for accurate assessment. The use of differential flame graphs helps in visualizing performance changes pre- and post-optimizations.
Performance Optimization Techniques: He discusses multiple optimization techniques, such as smart algorithm choices for routing and efficient data handling. He notes that both high-level architectural changes and small, incremental improvements can significantly enhance overall performance.
Conclusion and Insights: The talk concludes with key insights on how even minor improvements in Ruby code can lead to substantial overall gains, especially as applications scale. Aritomo stresses the importance of keeping the benchmarking environment close to production conditions for accurate results and addresses common pitfalls in benchmarking practices.

The session showcases not just the methodologies for improving speed and efficiency in Ruby frameworks but also instills best practices around software performance monitoring and continuous integration of benchmarking into development workflows.