# Grab
> Southeast Asia's leading everyday "super-app" that provides ride-hailing, food delivery, grocery shopping, and digital financial services.

## Articles

### [Effortless enterprise authentication at Grab: Dex in action](https://yomu.fyi/post/effortless-enterprise-authentication-at-grab-dex-in-action.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Kah Wei Lee
- Published: May 23, 2025

Grab needed a centralised system to simplify identity management, satisfy audit requirements, and standardise authentication across internal and external tools like Databricks and Datadog. The engineering team selected OpenID Connect as their standard protocol and adopted Dex, an open-source CNCF identity aggregator. Dex acts as an intermediary between applications and multiple identity providers to issue standardised OIDC tokens. To secure service-to-service communication, Grab implemented token exchange with trusted peer relationships rather than relying on privileged service accounts. Dex also provides a kill-switch mechanism that can route authentication traffic to an alternate provider during identity provider outages.


### [From failure to success: The birth of GrabGPT, Grab’s internal ChatGPT](https://yomu.fyi/post/from-failure-to-success-the-birth-of-grabgpt-grab-s-internal-chatgpt.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Wenbo Wei
- Published: May 19, 2025

Grab's machine learning platform team initially faced overwhelming volumes of repetitive user inquiries across their internal support channels. An initial attempt to automate answers using the open-source chatbot-ui framework and GPT-3.5-turbo failed to scale because the 8,000-token context limit could not accommodate extensive documentation, and embedding search proved inadequate. The project then pivoted to create an internal conversational AI platform called GrabGPT by wiring chatbot-ui with Google authentication and Grab's catwalk model-serving infrastructure. The resulting internal service rapidly expanded across the organization, providing auditable interactions, multi-model support across OpenAI, Claude, and Gemini, and private network routing to safeguard corporate data.


### [Streamlining RiskOps with the SOP agent framework](https://yomu.fyi/post/streamlining-riskops-with-the-sop-agent-framework.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Fujiao Liu
- Published: May 8, 2025

Manual Account Takeover (ATO) investigations in Risk Operations traditionally demand intensive cross-referencing across systems, manual SQL execution, and high-pressure decision-making prone to human error. To resolve these bottlenecks, an SOP-driven LLM agent framework models investigative workflows as natural-language tree structures with explicit function notations like @function\_name. Execution is coordinated between an SOP planner, which traverses the tree using a Depth-First Search strategy, and a Worker Agent that parses JSON-formatted steps to invoke database queries and APIs. Once all steps evaluate their decision criteria, the framework synthesizes the collected data into an actionable summary report. Implementing this architecture automated 87% of ATO cases and dropped average ticket handling time from 22 minutes to 3 minutes.


### [Introducing the SOP-driven LLM agent frameworks](https://yomu.fyi/post/introducing-the-sop-driven-llm-agent-frameworks.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Fujiao Liu
- Published: Apr 25, 2025

Standard operating procedure (SOP) driven Large Language Model agent frameworks address common generative AI challenges such as hallucinations, non-standard output formats, and branching navigation errors. Workflows are represented as hierarchical trees where nodes encapsulate actions or decision points that can be created using a visual editor and annotated with explicit external function calls. Execution relies on a tripartite architecture consisting of a Depth-First Search planner module with backtracking, an adaptive worker agent that limits API exposure and compresses context, and a multilingual user agent. Supporting tools include a Graph Retrieval-Augmented Generation pipeline, a plugin system integrating Python and SQL, and a state stack for pausing workflows during human intervention. In production deployments for fraud and account takeover investigations, the framework automated up to 87% of cases while cutting handling times substantially.


### [Evaluating performance impact of removing Redis-cache from a Scylla-backed service](https://yomu.fyi/post/evaluating-performance-impact-of-removing-redis-cache-from-a-scylla-ba.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Md Riyadh
- Published: Apr 11, 2025

Grab operates a high-throughput Rust read service that aggregates counter metrics from Scylla tables across minutely, hourly, and daily granularities. The service initially cached aggregated responses in Redis using keys rounded to 15-minute intervals alongside a five-minute TTL. Because incoming queries predominantly requested recent data, transitions between 15-minute windows caused simultaneous cache misses across active configurations, resulting in severe Scylla traffic spikes, latency surges, and timeouts. To resolve the load imbalance, engineers proposed removing the Redis cache entirely and relying directly on Scylla's native internal caching. The rollout was staged in production by deterministically disabling Redis caching for specific counter configurations using mathematical operations on configuration IDs.


### [Facilitating Docs-as-Code implementation for users unfamiliar with Markdown](https://yomu.fyi/post/facilitating-docs-as-code-implementation-for-users-unfamiliar-with-mar.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: David Khu
- Published: Apr 4, 2025

Adopting Docs-as-Code practices at Grab posed challenges for non-engineering team members who lacked familiarity with GitLab and Markdown syntax. To bridge this gap, Grab built a rich-text WYSIWYG TechDocs editor directly into their Backstage developer portal while preserving GitLab as the central storage backend. The team selected the Lexical framework over alternatives to enable deep customization and support non-standard elements like Kroki diagrams, Draw.io, and Excalidraw. The editor integrates OAuth 2.0 authentication to generate single-commit merge requests automatically and uses a split-screen live preview alongside concurrent session tracking to minimize Git conflicts. This approach lowered the technical barrier for non-engineers to contribute to documentation without disrupting standard repository workflows.


### [Improving Hugo stability and addressing oncall challenges through automation](https://yomu.fyi/post/improving-hugo-stability-and-addressing-oncall-challenges-through-auto.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Shuguang Xiang
- Published: Mar 20, 2025

Grab's Hugo platform manages over 4,000 data ingestion pipelines for the company's data lake, but recurring failures caused significant on-call strain and data downtime due to complex triage processes. To resolve these operational challenges, an automated architecture was introduced featuring signal collection, automated diagnosis, root-cause tracking, auto-resolution, and a central dashboard. Rather than parsing extensive execution logs from Spark or Airflow, the diagnosis engine analyzes direct computation signals and temporal execution steps in parallel to pinpoint assignees and root causes. An asynchronous auto-resolution framework executes custom recovery handlers, such as automated backoff retries during database replica lags. This automated workflow reduced on-call workloads, improved dataset visibility, and shortened issue triage times across Grab's data ecosystem.


### [Building a Spark observability product with StarRocks: Real-time and historical performance analysis](https://yomu.fyi/post/building-a-spark-observability-product-with-starrocks-real-time-and-hi.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Huong Vuong
- Published: Mar 6, 2025

Grab redesigned its Spark observability platform, Iris, to overcome limitations associated with its previous Telegraf, InfluxDB, and Grafana stack. InfluxDB presented operational challenges due to limited SQL compatibility, poor handling of string metadata, and query degradation on high-cardinality identifiers. The team replaced InfluxDB with StarRocks to serve as a unified analytical engine for both real-time cluster metrics and historical analysis. StarRocks ingests metrics directly from Kafka via routine load tasks, storing worker and Spark event data in partitioned duplicate-key OLAP tables linked by worker and application identifiers. This architecture eliminated intermediate ingestion agents, simplified S3 data lake backups, and enabled a custom web application alongside Superset for consistent querying.


### [TechDocs at Grab: Cultivating a culture of quality documentation](https://yomu.fyi/post/techdocs-at-grab-cultivating-a-culture-of-quality-documentation.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: David Khu
- Published: Feb 27, 2025

Engineering organizations frequently struggle with fragmented documentation, stale content, and a lack of clear ownership across disparate tools. To address these issues, Grab established TechDocs on its central Helix platform, embedding a Docs-as-Code workflow into daily engineering routines. Feedback gathered from quantitative surveys and one-on-one sessions shaped governance policies, separating stable platform documentation stored in GitLab from collaborative artifacts like RFCs in Confluence. To sustain document freshness, the platform assigns mandatory points of contact, displays last-updated timestamps, and flags pages untouched for more than three months.


### [Grab AI Gateway: Connecting Grabbers to multiple GenAI providers](https://yomu.fyi/post/grab-ai-gateway-connecting-grabbers-to-multiple-genai-providers.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Bjorn Jee
- Published: Feb 19, 2025

Grab built the AI Gateway to centralize access, cost control, and security across external and open-source Generative AI providers such as OpenAI, Azure, AWS, and Google. Designed as a set of lightweight reverse proxies, the gateway manages authentication, rate limiting, and authorization while translating payloads into a unified OpenAI-compatible interface. The platform archives request metadata and calculated per-call costs into a central data lake for auditing and showback, dynamically routing traffic across shared reserved capacity and regions to mitigate quota throttling. Supporting over 300 internal use cases, the system integrates directly with internal development notebooks and deployment tools to power applications ranging from real-time audio safety analysis to automated content moderation.


### [Embracing passwordless authentication with Grab’s Passkey](https://yomu.fyi/post/embracing-passwordless-authentication-with-grab-s-passkey.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Ocean Nguyen
- Published: Dec 26, 2024

Grab introduced Passkey to replace vulnerable traditional passwords and cumbersome multi-factor methods with a seamless, phishing-resistant alternative based on the FIDO standard. The architecture relies on an authenticator located on the user's device, a frontend client, and a backend storing only public keys and metadata. During registration and login, the frontend invokes WebAuthn APIs such as navigator.credentials.create and navigator.credentials.get using server-generated challenges to prevent replay attacks. Passkeys synchronize across ecosystems via Google Password Manager and Apple iCloud Keychain, allowing users to authorize logins with their device lock screen. This implementation improves user experience, eliminates the need to store secrets in backend databases, and cuts third-party communication costs associated with OTP delivery.


### [Turbocharging GrabUnlimited with Temporal](https://yomu.fyi/post/turbocharging-grabunlimited-with-temporal.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Michel Parreno
- Published: Dec 12, 2024

GrabUnlimited experienced scaling bottlenecks, corrupted membership states, and elevated production incidents after its subscriber base grew by over 1000%. The original architecture relied on Amazon SQS state machines, 5-minute Redis locks, and daily batch cron jobs that overwhelmed the database and lacked granular idempotency during upstream retries. To eliminate these failure modes, the engineering team migrated the core membership lifecycle to Temporal's workflow orchestration engine. Replacing batch cron jobs with Temporal Timers distributed renewal operations throughout the day, while matching workflow IDs prevented race conditions between renewals and cancellations. This architectural transition resolved database bottlenecks and yielded an 80% reduction in open production incidents.


### [How we seamlessly migrated high volume real-time streaming traffic from one service to another with zero data loss and duplication](https://yomu.fyi/post/how-we-seamlessly-migrated-high-volume-real-time-streaming-traffic-fro.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Md Riyadh
- Published: Dec 5, 2024

Grab split a backend service's read and write functionalities into separate services to allow independent scaling. Migrating the write path required transferring processing from 16 source Kafka streams—averaging 20,000 reads per second into DynamoDB tables and output streams—with zero data loss or duplication. Standard feature flags were ruled out because rollout propagation delays could introduce minutes of duplicate or missing data during flag toggling. Instead, engineers extracted processing logic into a shared monorepo commons package that used coordinated timestamps to trigger simultaneous cutovers across both services. Temporary validation sinks verified processing accuracy in production prior to the cutover, completing the stream-by-stream migration across three weeks without downtime.


### [Supercharging LLM application development with LLM-Kit](https://yomu.fyi/post/supercharging-llm-application-development-with-llm-kit.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Boon Zhan Chew
- Published: Nov 29, 2024

Grab developed LLM-Kit to resolve standardization, security, observability, and infrastructure provisioning bottlenecks across its generative AI development efforts. Submitting an initial application request automatically triggers project generation in GitLab, outputting a modular codebase along with Terraform definitions for Amazon EKS and ECR. The scaffolded architecture incorporates FastAPI, LangChain, OpenID Connect authentication helpers, and PGVector alongside HashiCorp Vault for credential management. Observability and quality tracking are built in through direct integrations with Datadog and LangSmith evaluations. By providing these standardized paved-road templates, the framework has onboarded hundreds of generative AI applications and saved teams an estimated 1.5 weeks of initial setup time.


### [How we reduced initialisation time of Product Configuration Management SDK](https://yomu.fyi/post/how-we-reduced-initialisation-time-of-product-configuration-management.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Ram Dilip Pradhan
- Published: Nov 22, 2024

GrabX operates as Grab's central platform for product configuration management, where client services fetch configuration data via an eventually consistent SDK. Services handling around 400 MB of configuration data experienced startup cold starts taking approximately four minutes, creating service stress during traffic spikes. The engineering team resolved this bottleneck through a multi-phase optimization of how the SDK retrieves data from AWS S3. First, sequential downloads of common and service-specific datasets were replaced with concurrent fetching. Next, concurrent downloading and memory loading were applied across large configurations within subscribed services, followed by the complete removal of an outdated disk-caching fallback mechanism. Benchmarks across diverse configuration payloads showed an overall initialisation time reduction of up to 90%.


### [Metasense V2: Enhancing, improving and productionisation of LLM powered data governance](https://yomu.fyi/post/metasense-v2-enhancing-improving-and-productionisation-of-llm-powered.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Nick Buhrer
- Published: Nov 14, 2024

Grab scaled Metasense to automate metadata generation, column-level classification, and sensitivity tiering across its entire data lake. Post-rollout analysis revealed that high tag volumes, wide tables, and mixed content—such as nested JSON and customer communications—strained model capacity and led to missed Personally Identifiable Information (PII). To overcome these limitations, the team split the classification process into distinct PII and non-PII tasks, reduced prompt word counts, and partitioned tables with over 150 columns into smaller units. Integrating LangChain and LangSmith modernized the architecture by enabling direct prompt experimentation, custom metric tracking, and version-controlled deployments. The updated pipeline achieved low misclassification rates alongside automated alert thresholds to trigger model improvement protocols if errors increase.


### [How we reduced peak memory and CPU usage of the product configuration management SDK](https://yomu.fyi/post/how-we-reduced-peak-memory-and-cpu-usage-of-the-product-configuration.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Ram Dilip Pradhan
- Published: Oct 30, 2024

Grab's central product configuration management platform, GrabX, previously aggregated all configurations across every backend service into a single JSON file hosted on AWS S3. Every minute, client SDKs fetched, parsed, and loaded this growing file—which exceeded 100MB—causing CPU throttling spikes, elevated P99 latency, and unnecessary memory consumption. Analysis revealed that 98% of services required less than 1% of the total configuration data. To resolve these bottlenecks, the team partitioned data by service, split configurations into separate S3 files under distinct prefixes, and introduced a per-service changelog for incremental updates. Benchmarks showed the redesign decreased maximum CPU utilisation by over 50% and reduced memory usage by up to 70%.


### [LLM-assisted vector similarity search](https://yomu.fyi/post/llm-assisted-vector-similarity-search.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Md Riyadh
- Published: Oct 23, 2024

Vector similarity search often struggles with conceptual nuances, negations, and complex constraints despite its efficiency in high-dimensional semantic retrieval. To address this limitation, a two-step retrieval pipeline combines Facebook AI Similarity Search (FAISS) using OpenAI's text-embedding-ada-002 embeddings with a large language model re-ranking step powered by GPT-4o. The initial FAISS search extracts a candidate shortlist of matches, which GPT-4o then re-ranks based on contextual relevance and query intent. Evaluations on structured datasets showed that while simple queries yielded comparable results across methods, the LLM-assisted approach effectively resolved negations and conceptual matching where raw vector search failed. Internal production trials on relational datasets exceeding 4,500 rows demonstrated similar relevance improvements, with additional query latency being the primary operational trade-off.


### [Leveraging RAG-powered LLMs for analytical tasks](https://yomu.fyi/post/leveraging-rag-powered-llms-for-analytical-tasks.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Edmund Hong
- Published: Oct 9, 2024

Data analysts at Grab faced an increasing volume of stakeholder data requests that required manually writing and executing repetitive SQL queries with minor parameter changes. To automate routine tasks like metric reporting and fraud investigations, the Integrity Analytics team paired an internal prompt-management platform, Spellvault, with Data-Arks, an in-house Python-based middleware that packages SQL queries and Python functions into APIs. A scheduler triggers automated report summarization, while an analytical bot named A\* bot executes relevant investigation queries via RAG and returns summarized findings in Slack. Automated report generation saves an estimated three to four hours per report and shortens multi-query fraud investigations to minutes. Grab favored RAG over fine-tuning because it avoids continuous retraining costs, scales faster across diverse use cases, and surfaces current production data.


### [Evolution of Catwalk: Model serving platform at Grab](https://yomu.fyi/post/evolution-of-catwalk-model-serving-platform-at-grab.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Vishal Sharma
- Published: Oct 1, 2024

Grab developed and scaled Catwalk, an internal machine learning model serving platform, to address operational bottlenecks, low resource utilization, and deployment friction between data scientists and backend engineers. The platform transitioned from an admin-managed TensorFlow Serving setup into a low-code self-service system supporting PyTorch and ONNX, before replacing complex Helm charts with Kubernetes Custom Resource Definitions for declarative, blue-green deployment orchestration. To support complex business workflows and multi-model applications, Grab subsequently introduced Catwalk Orchestrator with bundled deployments that allow individual services to scale independently. Across two years, the orchestrator architecture expanded to 200 deployed applications serving approximately 1,400 production machine learning models.


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