Replit Engineering

Replit EngineeringNotes from the people building Replit.https://replit-engineering-blog.pages.dev/<![CDATA[AI adoption starts with truth]]>https://replit-engineering-blog.pages.dev/ai-adoptionhttps://replit-engineering-blog.pages.dev/ai-adoptionMon, 03 Aug 2026 16:15:17 GMT<![CDATA[Closing the loop: Evaluating and improving Replit Agent at scale]]>https://replit-engineering-blog.pages.dev/evaluating-and-improving-agent-at-scalehttps://replit-engineering-blog.pages.dev/evaluating-and-improving-agent-at-scaleTue, 23 Jun 2026 20:22:20 GMT<![CDATA[We Built a Video Rendering Engine by Lying to the Browser About What Time It Is]]>https://replit-engineering-blog.pages.dev/browsers-dont-want-to-be-camerashttps://replit-engineering-blog.pages.dev/browsers-dont-want-to-be-camerasThu, 26 Feb 2026 16:30:00 GMT<![CDATA[Decision-Time Guidance: Keeping Replit Agent Reliable]]>https://replit-engineering-blog.pages.dev/decision-time-guidancehttps://replit-engineering-blog.pages.dev/decision-time-guidanceTue, 20 Jan 2026 21:00:00 GMT<![CDATA[How Replit Secures AI-Generated Code [white paper]]]>https://replit-engineering-blog.pages.dev/securing-ai-generated-codehttps://replit-engineering-blog.pages.dev/securing-ai-generated-codeThu, 15 Jan 2026 01:00:00 GMT<![CDATA[Inside Replit’s Snapshot Engine: The Tech Making AI Agents Safe]]>https://replit-engineering-blog.pages.dev/inside-replits-snapshot-enginehttps://replit-engineering-blog.pages.dev/inside-replits-snapshot-engineThu, 18 Dec 2025 01:29:00 GMT<![CDATA[Enabling Agent 3 to Self-Test at Scale with REPL-Based Verification]]>https://replit-engineering-blog.pages.dev/automated-self-testinghttps://replit-engineering-blog.pages.dev/automated-self-testingMon, 15 Dec 2025 18:31:59 GMT<![CDATA[Building Production-ready Apps with Automated Database Migrations on Replit]]>https://replit-engineering-blog.pages.dev/production-databases-automated-migrationshttps://replit-engineering-blog.pages.dev/production-databases-automated-migrationsWed, 10 Dec 2025 01:24:31 GMT<![CDATA[Using Tvix Store to Reduce Nix Storage Costs by 90%]]>https://replit-engineering-blog.pages.dev/tvix-storehttps://replit-engineering-blog.pages.dev/tvix-storeThu, 06 Mar 2025 04:46:22 GMT<![CDATA[Introducing Workflows]]>https://replit-engineering-blog.pages.dev/introducing-workflowshttps://replit-engineering-blog.pages.dev/introducing-workflowsThu, 27 Feb 2025 17:37:59 GMT<![CDATA[Replit's All-new Database Editor]]>https://replit-engineering-blog.pages.dev/database-editorhttps://replit-engineering-blog.pages.dev/database-editorWed, 26 Feb 2025 17:16:20 GMT<![CDATA[So you suspect you have a memory leak...]]>https://replit-engineering-blog.pages.dev/finding-and-solving-memory-leakshttps://replit-engineering-blog.pages.dev/finding-and-solving-memory-leaksTue, 26 Nov 2024 14:28:53 GMT<![CDATA[Shell2: 200× faster, persisted, multiplayer-native Shells]]>https://replit-engineering-blog.pages.dev/shell2https://replit-engineering-blog.pages.dev/shell2Fri, 11 Oct 2024 23:55:14 GMT<![CDATA[How Replit makes sense of code at scale]]>https://replit-engineering-blog.pages.dev/how-replit-makes-sense-of-code-at-scale-ai-datahttps://replit-engineering-blog.pages.dev/how-replit-makes-sense-of-code-at-scale-ai-dataWed, 14 Aug 2024 22:52:33 GMT<![CDATA[Improved Dependency Management]]>https://replit-engineering-blog.pages.dev/improved-dependency-managementhttps://replit-engineering-blog.pages.dev/improved-dependency-managementMon, 01 Jul 2024 16:18:22 GMT<![CDATA[Advanced port configuration]]>https://replit-engineering-blog.pages.dev/portshttps://replit-engineering-blog.pages.dev/portsFri, 05 Apr 2024 15:00:00 GMT<![CDATA[Searching Nixpkgs in Under 30 Milliseconds]]>https://replit-engineering-blog.pages.dev/nixpkgs-searchhttps://replit-engineering-blog.pages.dev/nixpkgs-searchFri, 29 Mar 2024 15:39:44 GMT<![CDATA[Replit + pip ]]>=3.0.2,<4 in requirements.txt), and finally, delete the other [tool.poetry...] sections from pyproject.toml. After that, the packaging infrastructure will use pip for all future operations going forward.]]>https://replit-engineering-blog.pages.dev/piphttps://replit-engineering-blog.pages.dev/pipThu, 15 Feb 2024 17:00:00 GMT<![CDATA[Easier Editing for .replit Files]]>https://replit-engineering-blog.pages.dev/replitfilehttps://replit-engineering-blog.pages.dev/replitfileTue, 06 Feb 2024 16:00:00 GMT<![CDATA[Landscape or Portrait? You Decide]]>https://replit-engineering-blog.pages.dev/rotation-on-mobilehttps://replit-engineering-blog.pages.dev/rotation-on-mobileThu, 28 Dec 2023 17:00:00 GMT<![CDATA[Dec 12 Incident Update: Secrets and repl.co Static Hosting Unavailable]]>https://replit-engineering-blog.pages.dev/dec-12-secrets-static-hostinghttps://replit-engineering-blog.pages.dev/dec-12-secrets-static-hostingThu, 21 Dec 2023 09:00:00 GMT<![CDATA[GitHub x Replit Workflows: Enhancing Developer Productivity]]>https://replit-engineering-blog.pages.dev/githubhttps://replit-engineering-blog.pages.dev/githubTue, 19 Dec 2023 17:00:00 GMT<![CDATA[Skip the README, let us install for you]]>https://replit-engineering-blog.pages.dev/system-dependencies-pythonhttps://replit-engineering-blog.pages.dev/system-dependencies-pythonFri, 15 Dec 2023 17:00:00 GMT<![CDATA[New and Improved Console]]>https://replit-engineering-blog.pages.dev/new-and-improved-consolehttps://replit-engineering-blog.pages.dev/new-and-improved-consoleThu, 07 Dec 2023 18:00:40 GMT<![CDATA[System Dependencies on Replit]]>https://replit-engineering-blog.pages.dev/system-dependencies-on-replithttps://replit-engineering-blog.pages.dev/system-dependencies-on-replitFri, 20 Oct 2023 20:51:00 GMT<![CDATA[Tabs and Spaces - Smarter Indentation]]>https://replit-engineering-blog.pages.dev/smarter-indentationhttps://replit-engineering-blog.pages.dev/smarter-indentationThu, 12 Oct 2023 20:51:00 GMT<![CDATA[Sep 29 Incident Update: Read-Only Repls]]>https://replit-engineering-blog.pages.dev/sep-29-read-only-replshttps://replit-engineering-blog.pages.dev/sep-29-read-only-replsWed, 04 Oct 2023 19:43:00 GMT<![CDATA[Changes to Hosting on Replit]]>https://replit-engineering-blog.pages.dev/hosting-changeshttps://replit-engineering-blog.pages.dev/hosting-changesThu, 28 Sep 2023 19:43:00 GMT<![CDATA[Upgrading Analytics for Deployments]]>https://replit-engineering-blog.pages.dev/deployments-analyticshttps://replit-engineering-blog.pages.dev/deployments-analyticsMon, 28 Aug 2023 00:00:00 GMT<![CDATA[Packages: Powered Up]]>https://replit-engineering-blog.pages.dev/packages-powered-uphttps://replit-engineering-blog.pages.dev/packages-powered-upFri, 25 Aug 2023 00:00:00 GMT<![CDATA[Performance Mystery: Is Golang's Startup Time Slow?]]>https://replit-engineering-blog.pages.dev/golang-performancehttps://replit-engineering-blog.pages.dev/golang-performanceFri, 18 Aug 2023 00:00:00 GMT<![CDATA[Improving the Inline Ghostwriter Experience]]>https://replit-engineering-blog.pages.dev/ghostwriter-inlinehttps://replit-engineering-blog.pages.dev/ghostwriter-inlineFri, 11 Aug 2023 00:00:00 GMT<![CDATA[Expand possibilities on Replit with Expandable Storage]]>https://replit-engineering-blog.pages.dev/expandable-storagehttps://replit-engineering-blog.pages.dev/expandable-storageTue, 08 Aug 2023 00:00:00 GMT<![CDATA[Why We Changed Our Resource Limits and Plans]]>https://replit-engineering-blog.pages.dev/new-limits-and-planshttps://replit-engineering-blog.pages.dev/new-limits-and-plansMon, 07 Aug 2023 00:00:00 GMT<![CDATA[Fewer Restarts and Faster Networking for All]]>https://replit-engineering-blog.pages.dev/faster-networkinghttps://replit-engineering-blog.pages.dev/faster-networkingFri, 04 Aug 2023 00:00:00 GMT<![CDATA[Rebuilding the Replit Filetree for Superior Performance and Accessibility]]>https://replit-engineering-blog.pages.dev/filetree-updateshttps://replit-engineering-blog.pages.dev/filetree-updatesTue, 01 Aug 2023 00:00:00 GMT<![CDATA[Replit Deployments: 3x Faster and Even More Features]]>https://replit-engineering-blog.pages.dev/deployments-updateshttps://replit-engineering-blog.pages.dev/deployments-updatesMon, 31 Jul 2023 00:00:00 GMT<![CDATA[Replit Storage: The Next Generation]]>https://replit-engineering-blog.pages.dev/replit-storage-the-next-generationhttps://replit-engineering-blog.pages.dev/replit-storage-the-next-generationWed, 19 Jul 2023 23:00:00 GMT<![CDATA[The Journey To Code Search]]>https://replit-engineering-blog.pages.dev/the-journey-to-code-searchhttps://replit-engineering-blog.pages.dev/the-journey-to-code-searchSun, 25 Jun 2023 00:00:00 GMT<![CDATA[June 6, 2023, Single-Sign-On Security Vulnerability]]>https://replit-engineering-blog.pages.dev/june-6-sso-security-vulnerabilityhttps://replit-engineering-blog.pages.dev/june-6-sso-security-vulnerabilityMon, 12 Jun 2023 12:00:00 GMT<![CDATA[Configurable Keybindings for the Workspace]]>https://replit-engineering-blog.pages.dev/configurable-keybindings-for-the-workspacehttps://replit-engineering-blog.pages.dev/configurable-keybindings-for-the-workspaceTue, 30 May 2023 00:00:00 GMT<![CDATA[Super Colliding Nix Stores: Nix Flakes for Millions of Developers]]>https://replit-engineering-blog.pages.dev/super-colliding-nix-storeshttps://replit-engineering-blog.pages.dev/super-colliding-nix-storesThu, 25 May 2023 17:40:00 GMT<![CDATA[Making Git Good]]>https://replit-engineering-blog.pages.dev/git-goodhttps://replit-engineering-blog.pages.dev/git-goodMon, 15 May 2023 00:00:00 GMT<![CDATA[Announcing Replit Extensions]]>https://replit-engineering-blog.pages.dev/extensionshttps://replit-engineering-blog.pages.dev/extensionsMon, 01 May 2023 17:00:00 GMT<![CDATA[How to train your own Large Language Models]]>https://replit-engineering-blog.pages.dev/llm-traininghttps://replit-engineering-blog.pages.dev/llm-trainingWed, 19 Apr 2023 00:00:00 GMT<![CDATA[Replit Deployments - the fastest way from idea → production]]>https://replit-engineering-blog.pages.dev/deployments-launchhttps://replit-engineering-blog.pages.dev/deployments-launchWed, 12 Apr 2023 00:00:00 GMT<![CDATA[Hackers, Pros, and Teams users can now code for hours without restarts]]>https://replit-engineering-blog.pages.dev/regular-vmshttps://replit-engineering-blog.pages.dev/regular-vmsThu, 06 Apr 2023 00:00:00 GMT<![CDATA[April 2 Potential GitHub Credentials Exposure]]>https://replit-engineering-blog.pages.dev/april-02-potential-github-credentials-exposurehttps://replit-engineering-blog.pages.dev/april-02-potential-github-credentials-exposureTue, 04 Apr 2023 02:00:00 GMT<![CDATA[Announcing Outbound Data Transfer Limits]]>https://replit-engineering-blog.pages.dev/announcing-outbound-data-transfer-limitshttps://replit-engineering-blog.pages.dev/announcing-outbound-data-transfer-limitsWed, 22 Mar 2023 14:45:00 GMT<![CDATA[Worldwide Repls, part 3: Firing Up The Engines]]>https://replit-engineering-blog.pages.dev/geo-part-3-deployhttps://replit-engineering-blog.pages.dev/geo-part-3-deployThu, 16 Mar 2023 16:00:00 GMT<![CDATA[Remote Access to Your Repls via SSH]]>https://replit-engineering-blog.pages.dev/sshhttps://replit-engineering-blog.pages.dev/sshThu, 02 Mar 2023 20:00:00 GMT<![CDATA[Replit x Weights & Biases Machine Learning Hackathon Winners]]>https://replit-engineering-blog.pages.dev/ml-hackathon-winnershttps://replit-engineering-blog.pages.dev/ml-hackathon-winnersTue, 21 Feb 2023 00:00:00 GMT<![CDATA[Apply for Replit’s first Machine Learning Hackathon]]>https://replit-engineering-blog.pages.dev/ml-hackathonhttps://replit-engineering-blog.pages.dev/ml-hackathonWed, 11 Jan 2023 00:00:00 GMT<![CDATA[Making Repl Identity More Accessible]]>https://replit-engineering-blog.pages.dev/repl-identity-via-clihttps://replit-engineering-blog.pages.dev/repl-identity-via-cliTue, 10 Jan 2023 22:00:00 GMT<![CDATA[Redesigning Cycles Transaction History]]>https://replit-engineering-blog.pages.dev/cycles-transaction-historyhttps://replit-engineering-blog.pages.dev/cycles-transaction-historyFri, 23 Dec 2022 00:00:00 GMT<![CDATA[Branching out the Filetree]]>https://replit-engineering-blog.pages.dev/filetreehttps://replit-engineering-blog.pages.dev/filetreeMon, 14 Nov 2022 00:00:00 GMT<![CDATA[Replit Mobile App]]>https://replit-engineering-blog.pages.dev/mobile-apphttps://replit-engineering-blog.pages.dev/mobile-appWed, 19 Oct 2022 08:00:00 GMT<![CDATA[Worldwide Repls, part 2: Load balancing for fun (although not quite profit)]]>https://replit-engineering-blog.pages.dev/geo-part-2-loadbalancinghttps://replit-engineering-blog.pages.dev/geo-part-2-loadbalancingFri, 23 Sep 2022 18:00:00 GMT<![CDATA[History++ - A Better Way to Do Versioning]]>https://replit-engineering-blog.pages.dev/history2-releasehttps://replit-engineering-blog.pages.dev/history2-releaseThu, 15 Sep 2022 00:00:00 GMT<![CDATA[Zero-Click Auth For Your Apps]]>https://replit-engineering-blog.pages.dev/repl-identityhttps://replit-engineering-blog.pages.dev/repl-identityTue, 02 Aug 2022 16:00:00 GMT<![CDATA[Get Replit Famous]]>https://replit-engineering-blog.pages.dev/replit-famoushttps://replit-engineering-blog.pages.dev/replit-famousThu, 28 Jul 2022 00:00:00 GMT<![CDATA[Revamping the GitHub Import Flow]]>https://replit-engineering-blog.pages.dev/nix-github-importshttps://replit-engineering-blog.pages.dev/nix-github-importsThu, 21 Jul 2022 00:00:00 GMT<![CDATA[Inspect your HTML/CSS/JS Repls with native DevTools]]>https://replit-engineering-blog.pages.dev/devtoolshttps://replit-engineering-blog.pages.dev/devtoolsFri, 15 Jul 2022 00:00:00 GMT<![CDATA[Leaky UIs]]>https://replit-engineering-blog.pages.dev/leaky-uishttps://replit-engineering-blog.pages.dev/leaky-uisWed, 13 Jul 2022 00:30:00 GMT<![CDATA[Worldwide Repls, part 1: The Control Plane]]>https://replit-engineering-blog.pages.dev/geo-part-1-controlplanehttps://replit-engineering-blog.pages.dev/geo-part-1-controlplaneFri, 08 Jul 2022 17:00:00 GMT<![CDATA[Improving Domain Linking for Repls]]>https://replit-engineering-blog.pages.dev/improved-domain-linkinghttps://replit-engineering-blog.pages.dev/improved-domain-linkingMon, 04 Jul 2022 16:00:00 GMT<![CDATA[QLTY SZN 1]]>https://replit-engineering-blog.pages.dev/qlty-sznhttps://replit-engineering-blog.pages.dev/qlty-sznMon, 18 Apr 2022 00:00:00 GMT<![CDATA[We Built a Search Engine]]>https://replit-engineering-blog.pages.dev/searchhttps://replit-engineering-blog.pages.dev/searchThu, 31 Mar 2022 00:00:00 GMT<![CDATA[Escaping Dirty Pipe (a.k.a. CVE-2022-0847), mostly unscathed]]>https://replit-engineering-blog.pages.dev/dirtypipe-kernel-vulnerabilityhttps://replit-engineering-blog.pages.dev/dirtypipe-kernel-vulnerabilityWed, 16 Mar 2022 18:00:00 GMT<![CDATA[Betting on CodeMirror]]>https://replit-engineering-blog.pages.dev/codemirrorhttps://replit-engineering-blog.pages.dev/codemirrorThu, 10 Mar 2022 00:00:00 GMT<![CDATA[All New Repls are Powered By Nix]]>https://replit-engineering-blog.pages.dev/powered-by-nixhttps://replit-engineering-blog.pages.dev/powered-by-nixWed, 23 Feb 2022 17:00:00 GMT<![CDATA[Announcing File Persistence in Hosted Apps… for Everyone!]]>https://replit-engineering-blog.pages.dev/filesystem-persistence-for-allhttps://replit-engineering-blog.pages.dev/filesystem-persistence-for-allFri, 11 Feb 2022 19:45:00 GMT<![CDATA[Making new Python repls 100x faster to start up]]>https://replit-engineering-blog.pages.dev/python-new-templatehttps://replit-engineering-blog.pages.dev/python-new-templateFri, 04 Feb 2022 19:45:00 GMT<![CDATA[Understanding Repl Resource Utilization]]>https://replit-engineering-blog.pages.dev/repl-resourceshttps://replit-engineering-blog.pages.dev/repl-resourcesMon, 31 Jan 2022 20:00:00 GMT<![CDATA[Going Where the Next Billion Creators Are]]>https://replit-engineering-blog.pages.dev/mobile-v2https://replit-engineering-blog.pages.dev/mobile-v2Fri, 21 Jan 2022 08:00:00 GMT<![CDATA[Migrating our Web App from Heroku to GCP]]>https://replit-engineering-blog.pages.dev/heroku2gcphttps://replit-engineering-blog.pages.dev/heroku2gcpTue, 11 Jan 2022 20:00:00 GMT<![CDATA[Implementing RUI, Replit's Design System]]>https://replit-engineering-blog.pages.dev/rui-enghttps://replit-engineering-blog.pages.dev/rui-engThu, 23 Dec 2021 00:00:00 GMT<![CDATA[Repl Space and Templates]]>https://replit-engineering-blog.pages.dev/replspace-templateshttps://replit-engineering-blog.pages.dev/replspace-templatesWed, 15 Dec 2021 05:00:00 GMT<![CDATA[Ace, CodeMirror, and Monaco: A Comparison of the Code Editors You Use in the Browser]]>https://replit-engineering-blog.pages.dev/code-editorshttps://replit-engineering-blog.pages.dev/code-editorsTue, 14 Dec 2021 00:00:00 GMT<![CDATA[Will Nix Overtake Docker?]]>https://replit-engineering-blog.pages.dev/nix-vs-dockerhttps://replit-engineering-blog.pages.dev/nix-vs-dockerMon, 29 Nov 2021 20:00:00 GMT<![CDATA[How to Set Up Your Own Mastodon Instance with Replit]]>https://replit-engineering-blog.pages.dev/setting-up-a-mastodonhttps://replit-engineering-blog.pages.dev/setting-up-a-mastodonMon, 22 Nov 2021 00:00:00 GMT<![CDATA[Announcing File Persistence in Hosted Apps for Hackers]]>https://replit-engineering-blog.pages.dev/replspace-filesystemshttps://replit-engineering-blog.pages.dev/replspace-filesystemsThu, 11 Nov 2021 21:30:00 GMT<![CDATA[Betting on Nix: donating $25K to the NixOS Foundation]]>https://replit-engineering-blog.pages.dev/betting-on-nixhttps://replit-engineering-blog.pages.dev/betting-on-nixMon, 25 Oct 2021 00:06:40 GMT<![CDATA[Solidity on Replit: Diving into Web3]]>https://replit-engineering-blog.pages.dev/solidityhttps://replit-engineering-blog.pages.dev/solidityThu, 14 Oct 2021 00:06:40 GMT<![CDATA[A New Code Editor for Mobile - CodeMirror 6]]>https://replit-engineering-blog.pages.dev/codemirror-mobilehttps://replit-engineering-blog.pages.dev/codemirror-mobileTue, 21 Sep 2021 00:00:00 GMT<![CDATA[The Internet of Fun]]>https://replit-engineering-blog.pages.dev/internet-of-funhttps://replit-engineering-blog.pages.dev/internet-of-funTue, 02 Feb 2021 05:00:00 GMT<![CDATA[We've Been Pwned]]>https://replit-engineering-blog.pages.dev/pwndhttps://replit-engineering-blog.pages.dev/pwndThu, 03 Dec 2020 05:00:00 GMT<![CDATA[Don't Let Your Development Environment Rot]]>https://replit-engineering-blog.pages.dev/rothttps://replit-engineering-blog.pages.dev/rotMon, 04 Jun 2018 07:00:00 GMT<![CDATA[Building Towards a Holistic Development Service]]>https://replit-engineering-blog.pages.dev/holistichttps://replit-engineering-blog.pages.dev/holisticMon, 27 Mar 2017 07:00:00 GMT<![CDATA[Learning Devops & AWS on the Job: Building and Scaling a Service]]>https://replit-engineering-blog.pages.dev/aws-simple-guidehttps://replit-engineering-blog.pages.dev/aws-simple-guideMon, 14 Nov 2016 08:00:00 GMT<![CDATA[API Docs]]>https://replit-engineering-blog.pages.dev/api-docshttps://replit-engineering-blog.pages.dev/api-docsFri, 24 Jun 2016 07:00:00 GMT<![CDATA[Engineering Blog Kitchen Sink]]>https://replit-engineering-blog.pages.dev/engineering-blog-kitchen-sinkhttps://replit-engineering-blog.pages.dev/engineering-blog-kitchen-sinkFri, 21 Aug 2015 09:00:00 GMT