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The engineering internet, summarised so you can actually read it.
Enhancing Ad Relevance: Integrating Real-Time Context into Sequential Recommender Models
Pinterest's sequential ads candidate generator inferred user embeddings offline from historical offsite conversions, which lacked real-time browsing context. Consequently, less than 1% of impressions on the Related Pins surface were attributed to this generator because its retrieved candidates struggled in downstream ranking. To resolve this limitation, engineers developed the Contextual Sequential Two Tower Model, integrating a context layer directly into the query tower alongside user demographic features. Offline training utilized synthetic context derived from positive conversion labels paired with high dropout rates to preserve sequence reliance, while serving split into offline Transformer inference and online context computation. Offline evaluations showed a 3x to 10x increase in Recall@K, and production deployment lifted median candidate relevance by 275% to 300% and overall ROAS by approximately 0.7%.
Pinterest EngineeringSentry ·
Monitor Unreal Engine Game Performance with Application Metrics
Unreal Engine games frequently experience performance issues such as frame-rate drops, hitches, and network degradation that do not register as application crashes. To address the lack of live production telemetry, the Sentry Unreal SDK introduces automatic performance metrics. The integration periodically samples frame times, network health, active UObject counts, physical memory usage, and garbage collection pause durations across desktop, console, and Android platforms. Telemetry entries attach contextual hardware and environment attributes alongside trace IDs to connect aggregate latency spikes directly to underlying traces and spans. Enabled by default in Unreal SDK version 1.11.0, this telemetry provides developers with fleet-wide visibility into hardware-specific bottlenecks across game releases.
Ivan TustanivskyiMongoDB ·
AI Is Changing What Customers Need From a Database. MongoDB 8.3 Is Built for It
MongoDB announced the general availability of MongoDB 8.3, designed to support high-throughput AI workloads without requiring application code changes. Compared to version 8.0, the release provides a 35 percent boost in write throughput, a 45 percent increase in read speeds, and 15 percent faster ACID transactions. Additionally, cross-region connectivity for AWS PrivateLink is now generally available, enabling private traffic routing between Atlas clusters across distinct AWS regions without public internet exposure. MongoDB Atlas supports deployments across 130 regions spanning AWS, Google Cloud, and Microsoft Azure, including multi-cloud cluster topologies. These infrastructure updates target enterprise demands for sub-100ms retrieval, sub-second context updates, zero downtime, and strict data residency compliance.
Ben CefaloGrab ·
Enhancing Flink deployment with shadow testing
Production deployments of Apache Flink applications at Grab previously risked up to ten minutes of downtime when new versions failed under live traffic or could not resume from existing checkpoints. To eliminate these deployment failures, Grab's Coban data streaming team introduced an optional shadow testing stage directly into their production Kubernetes deployment pipeline. The shadow pipeline runs new application releases in parallel with the active application for a default observation period of one hour before prompting promotion to main. Dynamic runtime configuration based on an injected environment variable redirects source consumer groups and isolates output to dedicated shadow sinks, metrics, and logs.
Tee Long LangSentry ·
Fixing JavaScript observability, one library at a time
JavaScript application performance monitoring tools rely on monkey-patching via require-in-the-middle and import-in-the-middle, which breaks with ECMAScript Modules, bundlers, and non-Node runtimes. To solve this, an initiative is replacing monkey-patching with Node's built-in diagnostics_channel TracingChannel API across server-side JavaScript libraries. Under this pattern, libraries publish structured events while monitoring vendors subscribe to them with zero overhead when unlistened. The author leveraged Claude Code workflows alongside direct maintainer communication to draft proposals, implement code, and manage reviews across 44 target packages. Ten libraries including mysql2, node-redis, ioredis, and unjs modules have merged support, while active efforts continue on shared OpenTelemetry mapper registries and remaining ecosystem packages.
Abdelrahman AwadAmazon ·
Navigating uncertainty in Amazon's middle-mile network
Amazon's middle-mile logistics network coordinates tens of millions of packages across hundreds of facilities while managing subtle demand variations and major operational disruptions. To solve this mixed-integer optimization challenge without combinatorial explosion, Amazon models routes at coarse time resolutions augmented by precomputed 15-minute timing bounds. The system uses Monte Carlo methods alongside a graph attention network featuring interconnected site graphs and origin-destination graphs to capture complex spatial correlations and flow interdependencies. By generating synthetic flow permutations, planners stress-test candidate network designs against hundreds of plausible scenarios to prioritize routing optionality. This risk-aware modeling approach preserves network flexibility, absorbs severe shocks, and yields potential cost savings while safeguarding delivery promises.
Ruth Misener, Hana Ku, Georgios PaschosSentry ·
Improved debugging for Expo apps with the React Native SDK
Expo applications generate approximately 75% of the total event volume received from React Native applications in Sentry. In response, Sentry updated its React Native SDK starting in version 8.10 to improve Expo debugging and performance monitoring workflows. The update automatically enriches events with Expo constants and over-the-air update context, including channels, runtime versions, and emergency launch warnings when an OTA update fails. Developers can track remote EAS Build lifecycle failures and successes using dedicated hooks configured in package.json. Performance instrumentation now supports span generation for Expo Router route prefetching as well as asset and image loading through wrapper functions around expo-image and expo-asset.
Aleksandr PantiukhovSlack ·
From SSH to REST: A Security-Driven Modernization of Slack’s EMR Data Pipelines
Slack's data platform accumulated over 700 SSH-based Airflow operators executing jobs directly on AWS Elastic MapReduce clusters, creating broad security surfaces and operational instability. Stateful SSH connections frequently failed when Kubernetes pods restarted, leaving orphaned zombie processes and preventing infrastructure modernization such as migrating EMR clusters to child accounts. To eliminate SSH access, Slack adopted a REST-based architecture using Quarry, a gateway providing unified REST APIs and token authentication across compute engines. For non-Hadoop CLI workloads, Slack leveraged YARN Distributed Shell to execute arbitrary shell scripts stored in Amazon S3 within managed, isolated YARN containers. The phased migration achieved zero downtime across eight data regions, unlocking reliable monitoring, simplified onboarding, and future initiatives like Spark on Kubernetes.
Mahendran VasagamAmazon ·
How mechanism design theory helps optimize Amazon-vendor collaboration
Amazon and its vendors face an asymmetric information problem when coordinating purchase orders across fulfillment centers because neither party shares proprietary cost, capacity, or demand data. To solve this coordination gap without exposing sensitive information, Amazon's Supply Chain Optimization Technologies organization designed Flo Pro by integrating the Vickrey-Clarke-Groves mechanism with the Consensus Planning Protocol. The distributed optimization framework uses the alternating-direction method of multipliers to coordinate iterative agent responses, calculating cost-benefit transfers across rolling six-week planning horizons. In lower-dimensional settings, Amazon also evaluated a transparent menu-of-contracts approach where vendors select optimal plans priced at Amazon's incurred costs. A nine-week pilot with a consumer-product manufacturer confirmed that Flo Pro successfully aligns incentives and achieves measurable cost savings.
Dirk BergemannSentry ·
Introducing Application Metrics: Track the signal, see the spike, jump to the trace
Sentry launched Application Metrics to capture application signals without pre-aggregating counters or discarding high-cardinality attributes like user IDs, project IDs, and regions. The system supports counters, distributions, and gauges within the existing SDK while linking each metric event directly to trace IDs for integrated debugging. Engineers demonstrated the feature by troubleshooting a Session Replay failure that triggered silently when sessions exceeded 1,000 video segments. By instrumenting distributions for replay event counts with project and replay attributes, the team isolated seven affected occurrences, navigated to connected traces and log lines, and reproduced the issue. Application Metrics comes enabled in recent SDK versions with 5GB included per plan.
Ben CoeOptimizing ML Workload Network Efficiency (Part I): Feature Trimmer
Pinterest deployed a root-leaf architecture for online machine learning serving to decouple CPU-based feature preprocessing from GPU-based inference. Because the root cluster retrieved a union of features across models and fanned out the full set to every leaf, network bandwidth became a severe bottleneck. After initial tests with fbthrift LZ4 compression yielded a 20% bandwidth reduction at the cost of CPU and latency overhead, the team implemented Feature Trimmer. This mechanism uses exported model signatures as the source of truth to prune unused features on the root before transmission. By dispatching only required features per model, the system reduced network bandwidth, decreased latency, and enabled cluster rightsizing that saved over $4M annually.
Pinterest EngineeringGrab ·
Data Mesh at Grab (Part II): The foundational tools behind certification
Grab operationalizes its Signals Marketplace data mesh through integrated platforms designed for continuous data certification and observability. The central metadata management platform, Hubble, extends open-source DataHub to model metadata as an event-driven graph and expose search, lineage, ownership, and data contracts. An automated certification engine built on the DataHub Actions framework continuously evaluates metadata changes, classifying assets into Uncertified, Certified, CertifiedPlus, or Revoked states. Genchi serves as the data quality observability layer, using Temporal and Kafka to run checks for freshness, volume completeness, schema stability, and semantic rules. To eliminate false-positive alerts caused by decoupled cron schedules, Genchi integrates with the Lighthouse monitoring service to trigger quality tests immediately upon pipeline completion.
Aezo TeoSentry ·
Two commands to Sentry: now on Stripe Projects
Sentry is now integrated into Stripe Projects, enabling developers and coding agents to discover, provision, and manage Sentry services directly through the command-line interface. Running initialization and addition commands automatically sets up accounts, generates necessary environment variables like auth tokens and DSNs, and scaffolds agent skill files for tools such as Claude Code and Cursor. The integration supports plan upgrades, downgrades, and the addition of the Seer AI debugging assistant with billing handled through existing Stripe payment methods. Additional CLI capabilities include minting single-use magic login URLs for the Sentry dashboard, managing multi-member team collaboration tied to Stripe organizations, and rotating project credentials directly into local environment files.
Burak Yiğit KayaEvaluating AI at Scale: How Thumbtack Approaches Reliability, Safety, and Quality in GenAI
Thumbtack evaluates generative AI features across customer and service professional experiences to prevent unsupported claims, tone inconsistencies, and safety issues. The engineering organization transitioned from decentralized evaluation efforts to a dedicated cross-functional Evals team that provides shared infrastructure while preserving product team autonomy. System architectures combine rule-based checks, AI-as-a-judge scorers powered by DeepEval, trust and safety assessments, and crowdsourced human reviews. Teams leverage three parallel orchestration paths, including an MLflow-tracked stack, nightly Databricks batch jobs integrated with data warehouses, and multi-layer human-in-the-loop pipelines. Future milestones target centralized LLM judge registries, full task journey evaluations, automated judge-writing workflows, and cost-aware evaluation orchestration.
Thumbtack EngineeringFrom Clicks to Conversions: Architecting Shopping Conversion Candidate Generation at Pinterest
Pinterest built a dedicated shopping candidate generation model to optimize for lower-funnel purchase conversions rather than relying strictly on engagement retrieval models. Because offsite conversion events are sparse and delayed, engineers trained a single multi-surface two-tower model using conversion data supplemented by duration-weighted click engagement and unengaged ad impressions as hard negatives. The two-tower retrieval architecture incorporates a parallel DCN v2 and MLP layer structure that allows simultaneous learning from the same inputs without information bottlenecks. Later revisions transitioned the system from a multi-head loss structure to a unified single-head multi-task architecture paired with an advertiser-level objective. Deployed across more than 600 million monthly active users, the system increased shopping conversion volume by 2.3% and boosted return on ad spend by 3.1% for United States shopping campaigns.
Pinterest EngineeringLyft ·
How We Built a Smarter Pickup Experience for Gated Communities
Pickups in gated communities account for up to 30% of Lyft rides in certain markets, yet locked gates and lack of advance instructions historically resulted in higher cancellation rates and extended wait times. To resolve these friction points, Lyft's Mapping team developed an end-to-end mapping and routing framework. The team built an algorithm to generate gate area boundaries, enabling the app to detect gated communities and offer riders explicit choices between waiting inside or meeting outside the gate. Routing services incorporate the gate as an intermediate waypoint to direct drivers along the proper approach path while triggering timely gate access instructions. Following deployment, rides with shared gate instructions exhibited lower cancellation rates from both parties, shorter walking distances to pickup spots, and fewer extended driver wait times.
winnieyanYelp ·
How Yelp Keeps Server-Driven UI Consistent Across Four Platforms
Yelp maintains two major applications across Web, iOS, and Android, which previously led to fragmented server-driven UI implementations with mismatched backend component representations. To unify its server-driven UI framework, CHAOS, with its cross-platform design system, Cookbook, Yelp built an automated bridge library called Konbini. Konbini reads centralized JSON interface definitions through Jenkins pipelines to automatically generate synchronized libraries for Python, Kotlin, Swift, and TypeScript. These generated libraries handle component serialization on the backend and deserialization on client platforms. To maintain backward compatibility when component interfaces introduce breaking changes, client requests pass versioned spec identifiers, prompting the backend to execute migration methods that downcast newer component models to older supported versions.
Radu Comaneci, Software EngineerLeveraging AI to build a faster iOS CI system
iOS continuous integration at Thumbtack previously required 30 to 40 minutes per pull request because every change triggered all 400 or more tests for an affected app. To solve node exhaustion and prepare for increased AI-generated code volume, the infrastructure team built Smart Test Selection. The system relies on a nightly pipeline that executes the full test suite with coverage instrumentation to generate a JSON map connecting source files to test classes. When a pull request opens, the pipeline looks up changed files in this map and runs only the relevant tests instead of the full suite. Built using Groovy, Ruby, and Bash, the tool reduces typical continuous integration time by approximately 50 percent while cutting documentation-only validation by about 90 percent.
Muhieddine EL KaissiGithub ·
How GitHub uses eBPF to improve deployment safety
Deployment scripts can introduce dangerous circular dependencies when they rely on services or assets from platforms that are currently experiencing outages. Blocking network access at the host level is impractical because stateful nodes continue serving live traffic during rolling deployments. To solve this, GitHub isolates deploy scripts into dedicated Linux cGroups and attaches custom eBPF programs via the cilium/ebpf Go library. The system uses socket-address hooks to redirect DNS queries to a userspace proxy that checks a domain blocklist, while egress packet hooks map DNS transaction IDs to process IDs. This approach successfully prevents deploy-time circular dependencies, provides full command-line audit logs for blocked requests, and speeds up incident recovery.
Lawrence GripperMongoDB ·
New Research Reveals Overcoming Legacy Tech Issues Key to AI Success
An IDC survey of 1,400 organizations across eight Asia/Pacific markets reveals that legacy architectures and accumulated data debt severely hinder enterprise artificial intelligence initiatives. While 43% of surveyed organizations cite legacy systems as a major obstacle to application development, 95% report project delays and 90% have experienced failed modernization attempts. In contrast, high-performing organizations treat modernization as a continuous discipline across people, processes, and cloud-centric data platforms capable of processing both structured and unstructured workloads. These leading enterprises achieve nearly three times more digital revenue growth than peers still constrained by technical debt. IDC notes that addressing technical and data debt proactively avoids escalating AI failure rates and delivers superior return on investment compared to superficial lift-and-shift migrations.
Dr. William Lee