ruby-optimise

Community Ruby Best Practices Comprehensive performance optimization guide for Ruby applications, maintained by the community. Contains 42 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation. When to Apply Reference these guidelines when: Writing new Ruby code or gems Optimizing ActiveRecord queries and database access patterns Processing large collections or building data pipelines Reviewing code for memory bloat and GC pressure Configuring Ruby runtime settings for production Rule Categories by Priority Priority Category Impact Prefix 1 Object Allocation CRITICAL alloc- 2 Collection & Enumeration CRITICAL enum- 3 I/O & Database HIGH io- 4 String Handling HIGH str- 5 Method & Dispatch MEDIUM-HIGH meth- 6 Data Structures MEDIUM ds- 7 Concurrency MEDIUM conc- 8 Runtime & Configuration LOW-MEDIUM runtime- Quick Reference 1. Object Allocation (CRITICAL) alloc-avoid-unnecessary-dup - Avoid Unnecessary Object Duplication alloc-freeze-constants - Freeze Constant Collections alloc-lazy-initialization - Use Lazy Initialization for Expensive Objects alloc-avoid-temp-arrays - Avoid Temporary Array Creation alloc-reuse-buffers - Reuse Buffers in Loops alloc-avoid-implicit-conversions - Avoid Repeated Computation in Hot Paths 2. Collection & Enumeration (CRITICAL) enum-single-pass - Use Single-Pass Collection Transforms enum-lazy-large-collections - Use Lazy Enumerators for Large Collections enum-flat-map - Use flat_map Instead of map.flatten enum-each-with-object - Use each_with_object Over inject for Building Collections enum-avoid-count-in-loops - Avoid Recomputing Collection Size in Conditions enum-chunk-batch-processing - Use each_slice for Batch Processing 3. I/O & Database (HIGH) io-eager-load-associations - Eager Load ActiveRecord Associations io-select-only-needed-columns - Select Only Needed Columns io-batch-find-each - Use find_each for Large Record Sets io-avoid-queries-in-loops - Avoid Database Queries Inside Loops io-stream-large-files - Stream Large Files Line by Line io-connection-pool-sizing - Size Connection Pools to Match Thread Count io-cache-expensive-queries - Cache Expensive Database Results 4. String Handling (HIGH) str-frozen-literals - Enable Frozen String Literals str-shovel-over-plus - Use Shovel Operator for String Building str-interpolation-over-concatenation - Use String Interpolation Over Concatenation str-avoid-repeated-gsub - Chain gsub Calls into a Single Replacement str-symbol-for-identifiers - Use Symbols for Identifiers and Hash Keys 5. Method & Dispatch (MEDIUM-HIGH) meth-avoid-method-missing-hot-paths - Avoid method_missing in Hot Paths meth-cache-method-references - Cache Method References for Repeated Calls meth-block-vs-proc - Pass Blocks Directly Instead of Converting to Proc meth-avoid-dynamic-send - Avoid Dynamic send in Performance-Critical Code meth-reduce-method-chain-depth - Reduce Method Chain Depth in Hot Loops 6. Data Structures (MEDIUM) ds-set-for-membership - Use Set for Membership Tests ds-struct-over-openstruct - Use Struct Over OpenStruct ds-sort-by-over-sort - Use sort_by Instead of sort with Block ds-array-preallocation - Preallocate Arrays When Size Is Known ds-hash-default-value - Use Hash Default Values Instead of Conditional Assignment 7. Concurrency (MEDIUM) conc-fiber-for-io - Use Fibers for I/O-Bound Concurrency conc-thread-pool-sizing - Size Thread Pools to Match Workload conc-ractor-cpu-bound - Use Ractors for CPU-Bound Parallelism conc-avoid-shared-mutable-state - Avoid Shared Mutable State Between Threads 8. Runtime & Configuration (LOW-MEDIUM) runtime-enable-yjit - Enable YJIT for Production runtime-tune-gc-parameters - Tune GC Parameters for Your Workload runtime-frozen-string-literal-default - Set Frozen String Literal as Project Default runtime-optimize-require - Optimize Require Load Order How to Use Read individual reference files for detailed explanations and code examples: Section definitions - Category structure and impact levels Rule template - Template for adding new rules Reference Files File Description references/_sections.md Category definitions and ordering assets/templates/_template.md Template for new rules metadata.json Version and reference information