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Grab
Southeast Asia's leading everyday "super-app" that provides ride-hailing, food delivery, grocery shopping, and digital financial services.
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Evolution of quality at Grab
As Grab expanded its superapp, manual QA sign-offs led to prolonged testing cycles and a peak in major production defects around 2019. To counter defect leakage and improve delivery pace, the engineering organization transitioned to a shift-left testing strategy across its software development lifecycle. Quality engineers began writing Given/When/Then acceptance tests prior to coding so that software engineers could execute them during development, accompanied by Definition of Ready and Definition of Done standards. The team also structured a multi-layer test strategy spanning unit tests, pipeline-executed UI component tests with mocked APIs, backend integration tests, and a custom internal end-to-end framework. Between 2019 and 2022, these changes reduced major and critical production issues by 60% and development-phase critical bugs by 40%.
How OVO determined the right technology stack for their web-based projects
OVO faced maintainability issues caused by fragmented web technology stacks, including PHP, Vue, React, Nuxt, and Go, alongside outdated documentation. This fragmentation resulted in severe context-switching costs during code reviews and prolonged onboarding times for new engineers. To establish a single primary front-end stack, the team compared React and Vue against maintainability principles encompassing operability, simplicity, and evolvability. Vue was selected because its standardized framework structure and documentation minimized architectural variations across projects. Implementation entailed creating a standardized Vue boilerplate, updating the internal UI library, and scheduling periodic upgrades for legacy React services rather than migrating them entirely.
Migrating from Role to Attribute-based Access Control
Grab's streaming data platform team migrated the Kafka Control Plane from Role-Based Access Control to Attribute-Based Access Control to eliminate operational bottlenecks and manual permission management. The previous model required defining hundreds of roles, permissions, and group mappings in an internal IAM service, leading to approval delays and stale memberships. Under the new architecture, user attributes sync from the HRMS and token payloads, while resource attributes are tagged upon creation or backfilled to reflect department and team ownership. Open Policy Agent evaluates access requests defined in Rego via middleware by comparing user attributes with resource metadata. This transition eliminated over 200 roles, 200 permissions, and roughly 3,000 unused IAM resources while automating access provisioning for new joiners.
Securing GitOps pipelines
Grab's real-time data platform team transitioned from an Atlantis-driven Terraform workflow to an in-house GitOps platform called Khone to manage streaming infrastructure resources like Kafka topics and Flink pipelines. The earlier setup suffered from coarse-grained access controls, required manual merge request comments, and lacked flexible validation capabilities within native configuration files. Khone derives environment parameters directly from standardized directory paths and uses Python with the python-hcl2 library to inspect and validate resource definitions before executing Terraform stages in parallel. To prevent configuration tampering in merge requests, CI/CD pipeline definitions and execution scripts are isolated in a separate administrative repository and fetched during job runs using shallow Git clones.
New zoom freezing feature for Geohash plugin
Grab introduced a zoom freeze capability to its Geohash plugin for the Java OpenStreetMap Editor (JOSM). Previously, zooming in or out forced the plugin to calculate and render new geohashes automatically, causing visual clutter when users needed to focus on a specific region. The updated interface introduces a toggle label allowing editors to switch between enabling and disabling zoom freezing. While frozen, the current geohash boundaries remain locked during map scaling, and options to show smaller or larger geohashes are disabled. Disabling the feature instantly updates the display with the appropriate geohash subdivisions for the current zoom level.
Graph service platform
Grab's GrabDefence team required a dedicated graph infrastructure to proactively identify mobile fraud patterns, such as multiple accounts operating on shared physical devices and suspicious financial loops. To address this, the team built a four-layer Platform as a Service that encapsulates graph database operations behind uniform RESTful APIs for OLTP search and OLAP analysis. The architecture utilizes Amazon S3 for raw data files, Amazon Neptune for graph storage, DynamoDB for schema and metadata configurations, and Kafka for streaming ingestion. When users trigger data loading tasks, the service validates entity attributes against schemas stored in DynamoDB before importing records into Neptune. This infrastructure allows investigators to traverse adjacent account IDs and visualize complex entity relationships without managing underlying database runtimes.
Zero trust with Kafka
Grab's real-time data platform team transitioned their large-scale Kafka infrastructure from basic network access controls to a zero-trust architecture. The platform implements mutual Transport Layer Security (mTLS) for offline peer authentication and encryption, driven by HashiCorp Vault's PKI engine and Strimzi on Kubernetes. Policy-Based Access Control is enforced using dedicated Open Policy Agent deployments per cluster, backed by GitOps workflows where topic owners approve JSON authorization rules. To simplify client integration, the team enhanced their Go SDK to handle ephemeral in-memory certificates, automatic renewals, and configurable retries. While the security posture improved, the Java encryption and decryption overhead caused a drop in streaming throughput.
How KartaCam powers GrabMaps
Grab's Geo team required an efficient, low-cost way to collect fresh street-level imagery across Southeast Asia, where professional mapping equipment is prohibitively expensive and smartphone crowdsourcing yields inconsistent quality. To address this, Grab built KartaCam, a custom mapping device equipped with a 12MP sensor, dual-band GNSS, 4G LTE, and onboard edge AI. Edge machine learning models evaluate scene suitability, check image quality, filter for map-relevant objects, and blur personal data directly on the device prior to upload. Deploying a four-camera KartaCam 360 array delivers panoramic coverage and point-of-interest data comparable to commercial mapping rigs at roughly one-twentieth the hardware cost.
Graph for fraud detection
Rapid expansion across multiple business verticals introduced diverse, evolving fraud patterns at Grab, making traditional rule engines and decision trees inadequate due to their heavy reliance on extensive feature engineering and labeled data. To address cold starts and detect unknown fraud, the engineering team implemented a semi-supervised Relational Graph Convolutional Network (RGCN) across millions of connected ecosystem entities. The model propagates information along neighborhood nodes through graph convolutional layers to produce node embeddings and output fraud probabilities. Trained on graphs where only a small percentage of nodes are labeled, the RGCN achieved an AUROC close to 1 and distinctly separated fraudulent embeddings from genuine ones. The approach also offers high explainability by surfacing dense clusters of shared physical devices and addresses ongoing challenges in real-time prediction and noisy connections.
Query expansion based on user behaviour
Grab developed a query expansion framework to resolve search issues such as typos, multi-language terms, missing alternatives, and word spacing. The corpus is generated through manual annotation for the top thousand fat-head queries and session-based data mining of user rewrite patterns. Offline pipelines extract adjacent query rewrites occurring within 30 seconds where only the second query generated a click, limiting candidates to three per query for serving efficiency. In production, expanded keywords pass through a query understanding, multi-recall, and result fusion flow with automated pruning of underperforming pairs. Online A/B testing across six Southeast Asian countries showed improvements in click-through and conversion rates, with data-mined expansions outperforming manual annotations alone.
Using mobile sensor data to encourage safer driving
Dedicated vehicular inertial measurement units are prohibitively expensive to install across large fleets, while customer feedback lacks the coverage required to assess driving safety comprehensively. To monitor driver behavior at scale, Grab processes smartphone sensor data collected via a mobile telematics SDK at high sampling frequencies. A custom orientation algorithm calculates Euler roll and pitch angles from gravity and resolves yaw through principal component analysis to align phone measurements with vehicle axes. The pipeline applies low-pass or Kalman filtering to handle varying noise levels, followed by threshold peak-finding algorithms to detect harsh acceleration, braking, and cornering. Speeding events are identified by comparing GPS speeds against known map limits or aggregated speed profiles derived from free-flowing traffic.
Automatic rule backtesting with large quantities of data
Evaluating new or modified risk rules previously required Grab analysts to run slow offline Presto queries, manually construct payloads, or run rules in shadow mode for days. To standardize and accelerate this workflow, Grab developed an automated backtesting system powered by an AWS EMR Spark pipeline. Historical events are continuously ingested via Kafka and a Kubernetes stream pipeline into S3 using Snappy-compressed Parquet. Users configure replay intervals and rule definitions directly in the rule engine UI, which triggers asynchronous Spark jobs through Amazon SQS and Lambda. This automated simulation replaces multi-week shadow mode runs and generates downloadable aggregation metrics on transactions, user counts, and treatment outcomes.
How we store and process millions of orders daily
The Grab Order Platform processes millions of food and mart transactions daily, requiring high throughput, fault tolerance, and reduced cloud costs across transactional and analytical workloads. To meet these demands, the engineering team decoupled their database architecture by using Amazon DynamoDB for critical OLTP queries and MySQL RDS for historical OLAP queries. DynamoDB handles online order lifecycles with strong consistency, utilizing sparse Global Secondary Indexes for ongoing orders and TTL configurations to limit storage growth. Updates propagate asynchronously to MySQL RDS through a Kafka ingestion pipeline backed by Amazon SQS retries and timestamp-based version checks. This dual-database approach isolated core transaction availability from analytical queries and delivered significant cloud cost savings.
How we automated FAQ responses at Grab
Internal engineering on-call engineers at Grab spent substantial working hours handling repetitive questions in Slack channels, such as how-to inquiries and access permission requests. To resolve this without building an in-house tool, the team conducted an anonymized vendor comparison and selected OneBar through an employee voting process and a phased proof-of-concept. Initial rollouts were restricted by contract to 20 channels, leading the team to prioritize deployment based on Slack message volume and member counts. Populating the knowledge base required roughly a quarter of consistent updates alongside tech talks, while a targeted crowdsourcing campaign among new onboarders expanded the glossary and grew usage to approximately 3,000 users.
Graph Networks - 10X investigation with Graph Visualisations
Fraud detection traditionally required investigators to manually combine large datasets from disparate anti-fraud systems using statistical methods, which proved slow and inefficient. Grab built an interactive Graph Visualisation platform to transform raw records into connected visual maps without requiring manual queries or switching tools. The platform manages over three billion nodes and edges, allowing investigators to selectively expand data points and replay chronological events using temporal filters. Visual relationship mapping helps teams verify account appeals, uncover device-sharing rings, and spot anti-money laundering behavior through transaction density patterns.
How facial recognition technology keeps you safe
Grab utilizes facial recognition technology across its platform for driver authentication, passenger verification, and digital electronic Know Your Customer (e-KYC) processes. The core pipeline consists of image preprocessing through face detection and alignment, anti-spoofing checks, feature extraction into high-dimensional vector embeddings, and downstream verification or search. To counter spoof attacks like screen replays, synthetic moiré patterns are generated and cropped face patches are used during training and inference to focus on local structures rather than global semantic noise. Face verification challenges involving shallow ID datasets and masked faces are resolved using semi-Siamese training architectures and masked data augmentations.
Graph concepts and applications
Real-world systems generate dynamic, non-random connections that traditional statistical approaches fail to characterize or forecast. Graph models represent these structures through vertices and edges, abstracting complex networks into mathematically tractable relationships. Common data representation formats include the Resource Description Framework (RDF), which models subject-predicate-object triples with IRIs, literals, and blank nodes, and Labeled Property Graphs (LPGs), which store arbitrary key-value properties directly on nodes and edges. Graph databases, derived from the LPG model, treat relationships with equal weight to entities, delivering responsive traversals for highly interconnected systems. While they offer agility and explicit relationship modeling, graph databases lack a standardized query language and remain poorly suited for standard transaction-focused workloads compared to relational databases.
Automated Experiment Analysis - Making experimental analysis scalable
Manual ad-hoc analysis of online controlled experiments at Grab introduced operational inefficiencies, inconsistent quality control, and scalability barriers across teams. To resolve these issues, Grab extended its GrabX experimentation platform with an Automated Experiment Analysis system that standardises metrics and automates statistical evaluations. The architecture stores experiment configurations and metric definitions from Cosmos DB into Azure Data Lake as bronze datasets, uses Spark on Databricks via Azure Data Factory to process subjects into silver datasets, and applies an internal Python Decision Engine to generate final gold results. These gold datasets are stored in star-schema fact and dimension tables and presented directly in the GrabX interface using embedded Power BI visualisations. The automation eliminates repetitive data pipeline construction for analysts, ensures reproducible findings aligned with initial hypotheses, and accelerates product launch decisions.
Search architecture revamp
Before 2021, Grab’s Deliveries search architecture used an inverted index for textual matching, leaving it unable to account for user intention, context, or non-textual recall methods. Queries such as “Roti Prata” could prioritize merchant names over dishes, while the same query could imply different objectives by time or location; merging Ads and organic results at the Deliveries API layer also discarded recall-stage data. The revamped flow adds boosting, multi-recall, and ranking, enabling intent recognition, query expansion, embedding-based and graph-based recall, and joint ranking across business verticals. A platform-defined framework assembles service-team plugins through configuration, separating core flow from application logic and allowing components such as Ads and Mart recall to be reused across Food, Mart, and universal search flows. The resulting platform provides intent recognition, semantic search, mixed Ads-and-organic ranking, and simpler onboarding, while making new search modules and use cases easier to add.
Embracing a Docs-as-Code approach
Engineers at Grab faced difficulties finding and writing technical documentation because materials were fragmented across various platforms and disconnected from daily workflows. To establish a single source of truth, the organisation adopted a Docs-as-Code approach starting in 2021. Under this system, documentation is written in plaintext Markdown within dedicated folders inside each service's Git repository. An internal developer portal automatically builds and publishes documentation whenever updates are committed, integrating documentation maintenance into the standard code development and review workflow. By April 2022, approximately 80% of Grab services were projected to host their documentation on the internal portal, with the model also expanding to technical training content.
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