Latest fixes and solutions for performance errors on FixDevs.https://fixdevs.com/enThu, 09 Apr 2026 00:00:00 GMThttps://fixdevs.com/blog/locust-not-working/https://fixdevs.com/blog/locust-not-working/How to fix Locust errors — no locustfile found, User class not detected, worker connection refused, distributed mode throughput lower than single-node, StopUser exception, FastHttpUser vs HttpUser, and headless CSV reports.Thu, 09 Apr 2026 00:00:00 GMTpythonlocustload-testingperformancetestingdebuggingFixDevshttps://fixdevs.com/blog/wasm-not-working/https://fixdevs.com/blog/wasm-not-working/How to fix WebAssembly issues — instantiateStreaming vs instantiate, CORS for WASM files, linear memory limits, wasm-bindgen JS interop, imports/exports mismatch, and WASM in bundlers.Fri, 27 Mar 2026 00:00:00 GMTjavascriptwebassemblyfrontendperformancedebuggingFixDevshttps://fixdevs.com/blog/react-use-transition-not-working/https://fixdevs.com/blog/react-use-transition-not-working/How to fix React useTransition and startTransition issues — what counts as a transition, Suspense integration, concurrent rendering requirements, and common mistakes that prevent transitions from deferring.Thu, 26 Mar 2026 00:00:00 GMTreactjavascriptfrontenddebuggingperformanceFixDevshttps://fixdevs.com/blog/spring-cache-not-working/https://fixdevs.com/blog/spring-cache-not-working/How to fix Spring Boot @Cacheable issues — @EnableCaching missing, self-invocation bypass, key generation, TTL configuration, cache eviction, and Caffeine vs Redis setup.Thu, 26 Mar 2026 00:00:00 GMTspring-bootjavabackenddebuggingperformanceFixDevshttps://fixdevs.com/blog/web-worker-not-working/https://fixdevs.com/blog/web-worker-not-working/How to fix Web Worker issues — postMessage data cloning, module workers, error handling, SharedArrayBuffer setup, Comlink, and common reasons workers silently fail.Thu, 26 Mar 2026 00:00:00 GMTjavascriptfrontendperformancedebuggingbrowserFixDevshttps://fixdevs.com/blog/nextjs-font-not-loading/https://fixdevs.com/blog/nextjs-font-not-loading/How to fix Next.js font loading issues — next/font/google setup, CSS variable approach, local fonts, font-display settings, FOUT flash, and Tailwind CSS font integration.Sun, 22 Mar 2026 00:00:00 GMTnextjscssfrontendperformancedebuggingFixDevshttps://fixdevs.com/blog/postgres-index-not-used/https://fixdevs.com/blog/postgres-index-not-used/How to fix PostgreSQL indexes not being used — EXPLAIN ANALYZE output, function on indexed column, type mismatches, statistics staleness, partial indexes, and query planner costs.Sun, 22 Mar 2026 00:00:00 GMTpostgresqldatabasesqlperformancedebuggingFixDevshttps://fixdevs.com/blog/rails-n-plus-one-query/https://fixdevs.com/blog/rails-n-plus-one-query/How to fix Rails N+1 queries — includes vs joins vs preload vs eager_load, Bullet gem detection, avoiding N+1 in serializers and views, and counter caches.Sun, 22 Mar 2026 00:00:00 GMTrailsrubydatabasebackendperformancedebuggingFixDevshttps://fixdevs.com/blog/react-key-prop-warning/https://fixdevs.com/blog/react-key-prop-warning/How to fix React's missing key prop warning — why keys matter for reconciliation, choosing stable keys, avoiding index as key pitfalls, keys in fragments, and performance impact.Sun, 22 Mar 2026 00:00:00 GMTreactjavascriptfrontendperformancedebuggingFixDevshttps://fixdevs.com/blog/svelte-store-subscription-leak/https://fixdevs.com/blog/svelte-store-subscription-leak/How to fix Svelte store subscription memory leaks — auto-subscription with $, manual unsubscribe, derived store cleanup, custom store lifecycle, and SvelteKit SSR store handling.Sun, 22 Mar 2026 00:00:00 GMTsveltejavascriptfrontendperformancedebuggingFixDevshttps://fixdevs.com/blog/webpack-bundle-size-too-large/https://fixdevs.com/blog/webpack-bundle-size-too-large/How to reduce Webpack bundle size — code splitting, tree shaking, dynamic imports, bundle analysis, moment.js replacement, lodash optimization, and production build configuration.Sun, 22 Mar 2026 00:00:00 GMTwebpackjavascriptperformancefrontenddebuggingFixDevshttps://fixdevs.com/blog/docker-layer-cache-invalidated/https://fixdevs.com/blog/docker-layer-cache-invalidated/How to fix Docker layer cache being invalidated on every build — Dockerfile instruction order, COPY optimization, ARG vs ENV, BuildKit cache mounts, and .dockerignore.Sat, 21 Mar 2026 00:00:00 GMTdockerdevopsbackendperformancedebuggingFixDevshttps://fixdevs.com/blog/go-goroutine-leak/https://fixdevs.com/blog/go-goroutine-leak/How to find and fix goroutine leaks in Go — detecting leaks with pprof and goleak, blocked channel patterns, context cancellation, and goroutine lifecycle management.Sat, 21 Mar 2026 00:00:00 GMTgobackenddebuggingperformanceFixDevshttps://fixdevs.com/blog/mysql-index-not-used/https://fixdevs.com/blog/mysql-index-not-used/How to fix MySQL indexes not being used by the query optimizer — EXPLAIN output, implicit conversions, function on columns, composite index order, cardinality issues, and forcing indexes.Sat, 21 Mar 2026 00:00:00 GMTmysqldatabasebackendperformancedebuggingFixDevshttps://fixdevs.com/blog/prisma-n-plus-one/https://fixdevs.com/blog/prisma-n-plus-one/How to fix the N+1 query problem in Prisma — using include and select for eager loading, fluent API pitfalls, DataLoader integration, and query logging to detect N+1 patterns.Sat, 21 Mar 2026 00:00:00 GMTprismanodejstypescriptbackendperformanceFixDevshttps://fixdevs.com/blog/python-async-sync-mix/https://fixdevs.com/blog/python-async-sync-mix/How to fix Python asyncio event loop blocking — using run_in_executor for sync calls, asyncio.to_thread, avoiding blocking I/O in coroutines, and detecting event loop stalls.Sat, 21 Mar 2026 00:00:00 GMTpythonasynciobackendfastapidebuggingperformanceFixDevshttps://fixdevs.com/blog/go-context-deadline-exceeded/https://fixdevs.com/blog/go-context-deadline-exceeded/How to fix Go context.DeadlineExceeded and context.Canceled errors — setting timeouts correctly, propagating context through call chains, handling cancellation, and debugging which operation timed out.Fri, 20 Mar 2026 00:00:00 GMTgodebuggingbackendprogrammingperformanceFixDevshttps://fixdevs.com/blog/graphql-n-plus-one/https://fixdevs.com/blog/graphql-n-plus-one/How to fix the GraphQL N+1 query problem — understanding why it happens, implementing DataLoader for batching, using query complexity limits, and selecting efficient resolver patterns.Fri, 20 Mar 2026 00:00:00 GMTgraphqlnodejsbackendperformancedebuggingFixDevshttps://fixdevs.com/blog/kubernetes-oomkilled/https://fixdevs.com/blog/kubernetes-oomkilled/How to fix Kubernetes OOMKilled errors — understanding memory limits, finding memory leaks, setting correct resource requests and limits, and using Vertical Pod Autoscaler.Fri, 20 Mar 2026 00:00:00 GMTkubernetesdevopsdebuggingbackendperformanceFixDevshttps://fixdevs.com/blog/mysql-slow-query-optimization/https://fixdevs.com/blog/mysql-slow-query-optimization/How to diagnose and fix slow MySQL queries — enabling the slow query log, reading EXPLAIN output, adding indexes, fixing N+1 queries, and optimizing JOINs and ORDER BY.Fri, 20 Mar 2026 00:00:00 GMTmysqldatabaseperformancebackenddebuggingFixDevshttps://fixdevs.com/blog/node-heap-out-of-memory/https://fixdevs.com/blog/node-heap-out-of-memory/How to fix Node.js 'JavaScript heap out of memory' — increasing heap size, finding memory leaks with heap snapshots, fixing common leak patterns, and stream-based processing for large data.Fri, 20 Mar 2026 00:00:00 GMTnodejsjavascriptdebuggingperformancebackendFixDevshttps://fixdevs.com/blog/postgres-slow-query/https://fixdevs.com/blog/postgres-slow-query/How to diagnose and fix slow PostgreSQL queries — reading EXPLAIN ANALYZE output, adding the right indexes, fixing N+1 queries, optimizing joins, and using pg_stat_statements.Fri, 20 Mar 2026 00:00:00 GMTpostgresqldatabaseperformancebackenddebuggingFixDevshttps://fixdevs.com/blog/webpack-bundle-too-large/https://fixdevs.com/blog/webpack-bundle-too-large/How to reduce Webpack bundle size — code splitting, lazy loading, tree shaking, analyzing the bundle with webpack-bundle-analyzer, replacing heavy dependencies, and configuring splitChunks.Fri, 20 Mar 2026 00:00:00 GMTwebpackjavascriptperformancefrontenddebuggingFixDevshttps://fixdevs.com/blog/vite-build-chunk-size-warning/https://fixdevs.com/blog/vite-build-chunk-size-warning/How to fix Vite's chunk size warning — why bundles exceed 500 kB, how to split code with dynamic imports and manualChunks, configure the chunk size limit, and optimize your Vite production build.Mon, 16 Mar 2026 00:00:00 GMTvitejavascriptperformancefrontenddebuggingFixDevshttps://fixdevs.com/blog/aws-lambda-cold-start-timeout/https://fixdevs.com/blog/aws-lambda-cold-start-timeout/How to fix AWS Lambda cold start timeouts and slow first invocations — provisioned concurrency, reducing package size, connection reuse, and language-specific optimizations.Sun, 15 Mar 2026 00:00:00 GMTawslambdaserverlessdevopsperformanceFixDevshttps://fixdevs.com/blog/python-gil-threading-not-parallel/https://fixdevs.com/blog/python-gil-threading-not-parallel/How to fix Python threading not achieving parallelism due to the GIL — when to use multiprocessing, concurrent.futures, or asyncio instead, and what the GIL actually blocks.Sat, 14 Mar 2026 00:00:00 GMTpythonthreadingperformancemultiprocessingdebuggingFixDevshttps://fixdevs.com/blog/python-multiprocessing-not-working/https://fixdevs.com/blog/python-multiprocessing-not-working/How to fix Python multiprocessing not working — freeze_support error on Windows, pickle errors with lambdas, zombie processes, and Pool hanging indefinitely.Sat, 14 Mar 2026 00:00:00 GMTpythonmultiprocessingdebuggingperformanceFixDevshttps://fixdevs.com/blog/react-memo-not-working/https://fixdevs.com/blog/react-memo-not-working/How to fix React.memo not working — components still re-rendering despite being wrapped in memo, caused by new object/function references, missing useCallback, and incorrect comparison functions.Sat, 14 Mar 2026 00:00:00 GMTreactjavascriptperformancedebuggingFixDevshttps://fixdevs.com/blog/react-lazy-suspense-error/https://fixdevs.com/blog/react-lazy-suspense-error/How to fix React.lazy and Suspense errors — Element type is invalid, A React component suspended while rendering, Loading chunk failed, and lazy import mistakes with named vs default exports.Fri, 13 Mar 2026 00:00:00 GMTreactjavascriptwebpackperformancedebuggingFixDevshttps://fixdevs.com/blog/docker-build-no-cache/https://fixdevs.com/blog/docker-build-no-cache/How to fix Docker build cache not working when layers rebuild every time despite no changes, including layer ordering, .dockerignore, COPY invalidation, BuildKit cache mounts, and CI/CD cache strategies.Mon, 09 Mar 2026 00:00:00 GMTdockerdevopsperformanceFixDevs