Part 8: Zero-Downtime Map Updates & Multi-Region Kubernetes

Writing a fast algorithm is only half the battle. The true test of a Principal Engineer is deploying a massive, stateful Routing Engine to the Cloud without causing a single second of downtime during map updates or infrastructure failures. Answer-first: You cannot treat Graphhopper like a stateless web server. Updating the OpenStreetMap data takes 30 minutes of heavy computation. You MUST decouple the map build process using Kubernetes Jobs, inject the pre-computed 50GB cache via initContainers, and switch traffic instantly using Blue-Green Deployments. ...

June 15, 2026 · 5 min · Lê Tuấn Anh

Tech Radar (14/06/2026): Kratos & Dapr State Management

Welcome back to the Tech Radar bulletin. In modern Microservices architecture, maintaining a system capable of communicating flexibly both externally (HTTP) and internally (gRPC) is an essential requirement. Simultaneously, State Management in distributed environments demands rigorous solutions to prevent data collisions. Today, we will dissect how to combine Go’s highly acclaimed Kratos framework with Dapr v1.15 to comprehensively solve this problem. 1. Kratos Dual-Protocol: HTTP & gRPC Running in Parallel Answer-first: The Kratos framework integrates with Dapr v1.15 State Management via the sidecar pattern, allowing HTTP and gRPC servers to run concurrently. To avoid state collisions when running dual-protocol, the system uses Dapr ETags via SaveStateWithETag for Optimistic Concurrency Control, and uses Middleware for Metadata synchronization. ...

June 14, 2026 · 4 min · Lê Tuấn Anh

Tech Radar (13/06/2026): Go 1.26 GC, K8s Pod Resizing & AI-Native

Welcome back to the Tech Radar bulletin, where we filter out the noise of the tech industry to uncover the genuine trends shaping future System Architecture. The second week of June 2026 witnessed three massive shifts, from core infrastructure (Go, Kubernetes) to the maturation of AI-Native architecture. From the perspective of a System Architect, these are updates you cannot ignore to optimize your High-Concurrency systems. 1. Golang 1.26: “Green Tea” GC Architecture - The Savior for RAM-Hungry Microservices Enabled by default in Go 1.26, the Garbage Collector codenamed “Green Tea” is not just a performance patch; it is a core architectural overhaul. ...

June 13, 2026 · 4 min · Lê Tuấn Anh

Kubernetes In-Place Pod Resizing: Scale CPU & Memory Without Restart

Answer-first: In-Place Pod Resizing (GA in Kubernetes v1.35) allows you to modify CPU and memory requests/limits on running containers without restarting the pod — eliminating cold-start disruptions for AI inference, databases, and stateful workloads. This guide covers requirements, production YAML, VPA integration, cost optimization patterns, and gotchas. Before this feature, changing a container’s resource allocation required deleting and recreating the pod. For a stateful database holding connections, an AI model with 30GB of weights loaded in memory, or a long-running batch job — that restart is catastrophic. In-Place Pod Resize finally decouples resource management from pod lifecycle. ...

June 12, 2026 · 10 min · Lê Tuấn Anh

Go Microservices Architecture: Production Guide

Go microservices from domain design to Kubernetes deployment — gRPC, Dapr, OpenTelemetry, and GitOps patterns from a real 21-service production migration.

June 12, 2026 · 23 min · Lê Tuấn Anh

Tech Radar, June 11, 2026: K8s Pod Resizing, Agentic Workflows & Go 1.26

Welcome to today’s Tech Radar. The theme for this week is the maturation of the infrastructure layer. We are seeing Kubernetes finally adapt to the erratic resource demands of AI inference, a shift towards proactive “Machine Economy” agents, and Golang cementing its position as the ultimate orchestration language for local AI. Here are the signals you need to pay attention to. 1. Kubernetes: The Operating System for AI Platforms The shift of Kubernetes from a general-purpose microservices orchestrator to the de facto “AI OS” is fully cemented this week by two critical General Availability (GA) milestones: ...

June 11, 2026 · 4 min · Lê Tuấn Anh

Tech Radar, June 6, 2026: Vibe & Verify, K8s Security & WWDC26

Today is June 6, 2026. Following the June 2 radar on NVIDIA RTX Spark and Intel 18A at Computex, this week’s signals shift from silicon announcements to the engineering workbench itself: how you write code, how you secure your cluster, how the Java ecosystem is evolving — and what arrives at WWDC26 in 48 hours. Two parallel macro signals are reshaping the regional technology landscape: Eric Schmidt’s visit to Hanoi to advise Vietnam’s national AI strategy, and LG Innotek expanding its semiconductor substrate plant in northern Vietnam. Overlay that with the sharpest Nasdaq sell-off of the month — investors are now demanding that AI spend justify itself. ...

June 6, 2026 · 15 min · Lê Tuấn Anh

Go pprof in Kubernetes: Remote Profiling & Flame Graphs

Answer-first: How to safely profile CPU, memory, and goroutines in Go services running in Kubernetes using kubectl port-forward, pprof, and Pyroscope. You’ve instrumented your Go service with net/http/pprof, run go tool pprof locally against the development binary, and spotted the hot path in your flame graph. Then you deploy to Kubernetes and the bottleneck disappears — because the workload profile in Kubernetes differs from local testing (different request mix, connection pool pressure, GC behavior under actual memory pressure, scheduler interference from co-located pods). ...

June 1, 2026 · 13 min · Lê Tuấn Anh

PayPay Architecture: Scaling Payments to 70M Users

Answer-first: An in-depth look at PayPay’s engineering stack: handling 70M users and 7.8B transactions/year using TiDB, Kafka event sourcing, GitOps, and chaos engineering. PayPay launched in October 2018 and grew to 10 million users in just 3 months — a growth rate that no Japanese fintech had ever seen. By 2025, the platform had crossed 70 million registered users and processed 7.8 billion payments per year. Behind this growth is an engineering team that has had to scale not just their infrastructure, but their entire engineering culture: from service standardization and GitOps-driven deployments to chaos engineering and AI-powered fraud detection. ...

June 1, 2026 · 12 min · Lê Tuấn Anh

Self-Hosting GraphHopper on Kubernetes with OSM Data

Answer-first: Step-by-step guide to deploying GraphHopper on Kubernetes with OpenStreetMap data: Docker image, PVC for OSM PBF files, RAM tuning, and health probes. GraphHopper is arguably the most capable open-source routing engine available — it supports Contraction Hierarchies (CH) for sub-millisecond route queries, custom vehicle profiles, turn restrictions, and the full OpenStreetMap road network. The problem most teams encounter is not the algorithm; it is the operational challenge of running it in Kubernetes: loading a large OSM PBF file, sizing JVM memory correctly, handling the long CH pre-processing startup time, and updating map data without downtime. ...

June 1, 2026 · 10 min · Lê Tuấn Anh