# Developer Experience > 79 posts about Developer Experience, summarised, each linking to the original. ## Articles ### [How We Improved Agent Chat Efficiency with Machine Learning](https://yomu.fyi/post/how-we-improved-agent-chat-efficiency-with-machine-learning.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Suman Anand - Published: Apr 19, 2021 Agent typing time represented a large portion of Grab's chat support journey, and 85% of messages were still free typed because agents customized static templates to fit their personal style. To accelerate typing across multilingual markets without robotic templates, Grab built SmartChat, a machine learning feature that provides contextual sentence completion. The team opted for a lightweight seq2seq architecture using single-layered GRU encoder-decoders in TensorFlow instead of bulky attention models to keep model latency under 100ms. The user interface was implemented in React using a content-editable div with inline typeahead suggestions activated via keyboard shortcuts. ### [How Grab is Blazing Through the Superapp Bazel Migration](https://yomu.fyi/post/how-grab-is-blazing-through-the-superapp-bazel-migration.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Sergii Grechukha - Published: Dec 3, 2020 Grab's mobile superapp scaled past 2.5 million lines of code across both Android and iOS, leading to unsustainable local and CI build times under Gradle and Xcode. To address these bottlenecks, the engineering team analyzed their dependency trees and introduced an internal tool to calculate and optimize the build critical path. They also deployed a Kubernetes-autoscaled remote build system using Mainframer for Android and implemented Test Impact Analysis to run only affected tests in pre-merge validation. While dependency decoupling yielded modest 7% to 10% gains and iOS remote builds proved unscalable on Apple hardware, Android remote builds reduced local compile times by up to 50%, and targeted test execution reduced pre-merge pipeline durations by more than 30%. ### [Our Journey to Continuous Delivery at Grab (Part 1)](https://yomu.fyi/post/our-journey-to-continuous-delivery-at-grab-part-1.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Sylvain Bougerel - Published: Sep 23, 2020 Around the end of 2018, Grab's backend architecture consisted of roughly 270 services managed through fragmented, manual deployment workflows. Engineers copied release parameters between build logs, wiki pages, Slack bots, and multiple Jenkins jobs, leading to high operational friction and an average of 10 business days between production updates for a service. To streamline delivery, Grab built Conveyor, an internal automation platform built on top of open-source Spinnaker. Conveyor introduced a custom user interface focused on pipeline visibility and a pipeline-as-code DSL called Artificer using Jsonnet files in the monorepository. The platform automatically registers build artifacts with commit metadata to eliminate manual parameter entry and automatically provisions integration, staging, and production pipelines. ### [Go Modules- A Guide for monorepos (Part 2)](https://yomu.fyi/post/go-modules-a-guide-for-monorepos-part-2.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Michael Cartmell - Published: Aug 12, 2020 Managing dependencies in a multi-module monorepo created developer friction at Grab due to unexpected changes from previous vendoring attempts and accidental imports. Because Go modules were not yet enabled directly for builds, the team implemented a continuous integration check that executes go mod vendor and rejects merge requests if any diffs exist in go.mod or the vendor directory. Adopting this CI check required configuring SSH deploy keys for private repositories, adding retry logic for network-related false positives, and standardizing on a single Go version to prevent checksum discrepancies. To streamline ongoing maintenance across hundreds of dependencies, the team developed an automated tool named AutoVend Bot. The bot runs go list -m -u all to detect updates and opens a scheduled batch of merge requests each day for human review. ### [How We Built Our In-house Chat Platform for the Web](https://yomu.fyi/post/how-we-built-our-in-house-chat-platform-for-the-web.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Vasu Krishnamoorthy - Published: Jun 29, 2020 Grab extended its in-house chat platform to the web to support its internal Customer Support portal. Because the existing TCP gateway only supports unicast connections with one active connection per user, opening multiple browser tabs would repeatedly disconnect previous tabs. Rather than undertaking a complex migration to multicast connections on the server, the team adopted a hybrid client-side strategy using SharedWorker and BroadcastChannel APIs. The implementation uses a SharedWorker to maintain a single WebSocket connection per domain while a BroadcastChannel syncs events across all open tabs. A custom wrapper over the worker manages version transitions during deployments to avoid race conditions across tabs. ### [Developer Platform updates Spring 20'](https://yomu.fyi/post/developer-platform-updates-spring-20.md) - Company: [Zoom](https://yomu.fyi/company/zoom.md) - Author: Michael Purnell - Published: Apr 21, 2020 Zoom introduced several updates across its developer platform alongside new roadmap milestones for 2020. Marketplace enhancements include a Developer Dashboard tracking install numbers and API usage, as well as dynamic OAuth scope configurations that distinguish mandatory and optional permissions. For client development, the WebSDK adds Microsoft Edge Chromium compatibility with video and VOIP support, whereas the iOS SDK incorporates Xcode 11 support. Due to increased developer demand, Zoom updated its V2 REST API rate limits and delivered new chat webhooks tracking message, channel, and member activity. Upcoming platform initiatives include the permanent termination of all legacy V1 APIs on May 31, 2020, platform security enhancements, and an iframe-free JavaScript embedding framework for the WebSDK. ### [Tackling UI Test Execution Time Imbalance for Xcode Parallel Testing](https://yomu.fyi/post/tackling-ui-test-execution-time-imbalance-for-xcode-parallel-testing.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Ngoc Thuyen Trinh - Published: Mar 16, 2020 Parallel test execution in Xcode can suffer from test time imbalance when tasks finish at significantly different times across parallel simulator workers. Analysis of Xcode scheduling logs shows that the runner groups tests by test class and dispatches all tests from the same class to a single simulator. Attempts to customize the suite by swizzling XCTestSuite fail because made-up suites initialize only after tests are dispatched. To overcome this grouping constraint, unique tokens or test names are appended to the class name component in \`-only-testing\` command-line arguments. This trick forces Xcode to treat each test as an independent class, successfully distributing individual tests across separate workers. ### [Developing Zoom Marketplace Apps w/ ngrok](https://yomu.fyi/post/developing-zoom-marketplace-apps-w-ngrok.md) - Company: [Zoom](https://yomu.fyi/company/zoom.md) - Author: Tim Slagle - Published: Feb 14, 2020 Developers frequently use ngrok to establish fast, introspectable tunnels to localhost when building Zoom Marketplace applications instead of configuring complex reverse proxies like NGINX or Apache. However, using basic ngrok tunnels in production exposes systems to short URL expiration windows, single points of failure, and scalability bottlenecks. To maintain application availability, developers can purchase an ngrok license to secure a service-level agreement and support. Additionally, teams should reserve dedicated subdomains rather than using auto-generated endpoints, run ngrok as a monitored background service on a cloud provider or data center, and place a load balancer in front of the tunnel to handle heavy traffic. ### [What’s New and What’s Coming for Zoom Marketplace in 2020?](https://yomu.fyi/post/what-s-new-and-what-s-coming-for-zoom-marketplace-in-2020.md) - Company: [Zoom](https://yomu.fyi/company/zoom.md) - Author: Benjamin Dean - Published: Feb 14, 2020 Zoom announced several updates to its App Marketplace alongside roadmap deadlines scheduled for early 2020. Marketplace enhancements include functional app categories, additional URL fields for Terms of Use and documentation, and support for defining multiple webhook event subscriptions within a single application. Administrators and developers gained webhook logs, enhanced pre-approval permission settings, and the ability to test draft applications directly in the installed apps interface for Data Compliance API compliance. To accommodate surging traffic, Zoom introduced revamped V2 REST API rate limits and breaking behavioral changes to the List Users API. Crucially, the platform set an absolute end-of-life date of April 26, 2020, for all legacy V1 APIs, requiring immediate migration to V2 endpoints. ### [Investing in Developers — Zoom Developer Summit and Competition 2020](https://yomu.fyi/post/investing-in-developers-zoom-developer-summit-and-competition-2020.md) - Company: [Zoom](https://yomu.fyi/company/zoom.md) - Author: Aleks Swerdlow - Published: Feb 13, 2020 Zoom launched the Zoom Marketplace Competition for developers creating applications on the Zoom platform. Open to for-profit organizations with less than $10M in prior funding, the competition offers a selected winner up to $2 million in potential investment. Finalists pitch their proposals to venture partners from Emergence, Horizons Ventures, Maven Ventures, and Sequoia. In addition to capital, the winner receives advisory sessions with Zoom product experts, priority platform support, a DTEN D7 whiteboard, and multiple three-year software licenses. Submissions require explicit details regarding problem definition, customer demographics, traction, revenue models, competitive analysis, and team credentials ahead of the March 31st, 2020 deadline. ### [Behind the Curtain: App Publishing Requests](https://yomu.fyi/post/behind-the-curtain-app-publishing-requests.md) - Company: [Zoom](https://yomu.fyi/company/zoom.md) - Author: Abraham Queen - Published: Jan 22, 2020 Zoom App Marketplace reviews App Publishing Requests to enable broad distribution of applications across all Zoom accounts. During the initial review stage, marketplace specialists evaluate submission metadata, including descriptive text, media assets, functional documentation, and requested scopes to verify that applications do not access unnecessary user information. Reviewers then perform a functional assessment by executing the developer-provided test plan using supplied test accounts and credentials. When issues occur, reviewers deliver feedback through review notes, requiring developers to resolve the problems and resubmit their app to trigger a re-review cycle. Developers can validate production readiness prior to public submission through account-level local testing or by creating a Publishable URL sharing request for external testing. ### [Marionette - Enabling E2E User-scenario Simulation](https://yomu.fyi/post/marionette-enabling-e2e-user-scenario-simulation.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Anish Jha - Published: Dec 23, 2019 Conducting end-to-end testing across Grab's transport microservices became difficult due to service availability, environment construction, cross-service authentication, and complex data setups for real-world user accounts. To address these challenges without relying on physical mobile devices or emulators, Grab built Marionette, an internal simulation platform for passenger and driver interactions. The platform provisions required test data, coordinates booking lifecycles, and isolates test executions across distinct user groups using localized cohorts. Engineers can configure driver and passenger behaviors, execute workflows, and run load or integration tests through a dedicated user interface, a Go SDK, and RESTful APIs. ### [Loki, a Dynamic Mock Server for HTTP/TCP Testing](https://yomu.fyi/post/loki-a-dynamic-mock-server-for-http-tcp-testing.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Thuy Nguyen - Published: Apr 10, 2019 Grab built Loki, a dynamic mock server written in Golang that simulates backend services on local developer machines and CI pipelines. Mobile app testing previously suffered from heavy dependencies on complex, brittle staging environments and interconnected services communicating over HTTP, HTTPS, and TCP. Loki handles both HTTP and TCP traffic on distinct ports while exposing a unified RESTful API to manage test expectations. It provides runtime flexibility through sandboxed JavaScript execution, configurable request sequence ordering, and an in-memory cron scheduler for TCP push messages. Adopting Loki decoupled mobile releases from staging stability, improving delivery cycles and enabling automated UI testing with Espresso and XCUITest. ### [Introducing Grab-Kit: Distributed Service Design at Grab](https://yomu.fyi/post/introducing-grab-kit-distributed-service-design-at-grab.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Karen Kue - Published: Jun 8, 2018 As Grab migrated from a monolith to microservices, maintaining consistency, coordination, and code quality across rapidly expanding teams became a major engineering challenge. To address this, the Developer Experience team built Grab-Kit, a Go framework that automates service scaffolding, code generation, and distributed system design patterns. The framework uses Protocol Buffer definition files as a single source of truth to generate data transfer objects, communication bindings, and standardized middleware for logging and profiling. Grab-Kit also features declarative metrics definitions that synchronize with the DataDog API to build and update service dashboards automatically. Adopting the framework reduced development time for creating new services by up to 70% in teams such as GrabFood while improving overall system stability. ### [Grab's Front End Study Guide](https://yomu.fyi/post/grab-s-front-end-study-guide.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Yangshun Tay - Published: Jun 3, 2017 Rapid hiring and engineering expansion created a steep learning curve for newcomers and backend engineers unfamiliar with modern web architecture. Grab created an opinionated front-end study guide to help engineers navigate JavaScript tooling, state management, and modern application practices. The guide frames client-side single-page applications as a scalable alternative to traditional server-side rendering, enabling clear client-server separation for multiple client apps hitting the same backend API. It establishes core competencies in ECMAScript 2015 via Babel and explains how component-driven interfaces in React improve maintainability and performance through virtual DOM reconciliation. Ultimately, the resource aims to ramp up developer onboarding and accelerate shipping speeds across web platforms. ### [Deep Dive into iOS Automation at Grab - Continuous Delivery](https://yomu.fyi/post/deep-dive-into-ios-automation-at-grab-continuous-delivery.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Sun Xiangxin - Published: Apr 23, 2017 Grab manages continuous delivery for its iOS applications using four build configurations per target: Adhoc QA, Hot Dogfood, Dogfood, and Testflight. The engineering team moved away from Fastlane in favor of custom bash scripts under 100 lines that execute clean builds and archives via xcodebuild. To eliminate manual logins for build execution, Grab developed a server-side Swift application integrating SlackKit and a bot named Iris. Incoming Slack commands are parsed and scheduled onto a serial DispatchQueue to trigger the appropriate build scripts. Deployment and rollback of updates to Iris and its build scripts are handled through Capistrano. ### [Deep Dive into iOS Automation at Grab - Integration Testing](https://yomu.fyi/post/deep-dive-into-ios-automation-at-grab-integration-testing.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Sun Xiangxin - Published: Apr 18, 2017 Grab replaced third-party cloud CI services with an in-house Xcode Server pipeline to run automated iOS integration tests across an expanding engineering team. Instead of performing fresh repository clones on shared cloud instances, Xcode Server pulls code incrementally and mirrors local developer configurations. The team automated testing bots through Ruby scripts and Arcanist hooks tied to Phabricator code reviews, dynamically provisioning bots on diffs and deleting them after merges. This architecture preserves step-by-step UI test execution logs and screenshots for easier failure diagnostics. To maintain stability on on-premises hardware, pre-integration scripts clear application cache states using simctl commands. ### [Programmers Beware - UX is Not Just for Designers](https://yomu.fyi/post/programmers-beware-ux-is-not-just-for-designers.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Corey Scott - Published: Jul 5, 2016 Software engineers frequently overlook user experience when designing APIs, SDKs, and code-level functions. Usability issues arise across various technical interfaces, from mobile apps forced to coordinate multiple round-trip network calls to ambiguous function signatures that obscure boolean arguments. To counter this, engineers can apply a five-question discovery framework to identify user identity, core objectives, user capabilities, ways to reduce user burden, and familiar paradigms. Practical remedies include sacrificing strict RESTful separation to merge mobile endpoints, placing validation logic inside internal RPC servers, and replacing boolean arguments with explicitly named helper functions. Ultimately, treating calling systems, end users, and fellow programmers as users shifts implementation complexity from consumers to servers. ### [Grab You Some Post-Mortem Reports](https://yomu.fyi/post/grab-you-some-post-mortem-reports.md) - Company: [Grab](https://yomu.fyi/company/grab.md) - Author: Lian Yuanlin - Published: Feb 4, 2016 Grab uses a Service-Oriented Architecture to deploy features quickly, but unfamiliarity across teams makes cross-service production debugging difficult. Historical incident reports lacked context, diagnostic details, impact data, and timelines, leaving outside engineers unable to learn from past outages. To address this, Grab established a four-pillar framework for post-mortem reports covering chronology, context, empowerment, and solutions. The approach mandates blameless, educational write-ups that categorize post-incident improvements across people, product, and process dimensions. Final reports undergo peer reviews by engineers from external teams to ensure clarity and remove bias. [Newer posts](https://yomu.fyi/topic/developer-experience/page/3.md)