Welcome to my nikki

Day 61

Kept building the AI resume builder, spotted a Semeia RoR opening in Toulouse, and caught up on France’s lackluster but entertaining third-place WC loss to England.

Tony Duong

Jul 20, 2026・1 min

Day 60

Walked with Fumika along the Touch in Lardenne, visited the Toulouse médiatheque, and built an AI resume builder with LinkedIn scraping to prep for the job search.

Tony Duong

Jul 18, 2026・1 min

Day 59

Finished POODR with chapter 9 on cost-effective tests — a concrete, well-organized book on object-oriented design that puts in writing a lot of what I already apply at work.

Tony Duong

Jul 17, 2026・1 min

POODR Chapter 9: Designing Cost-Effective Tests

Writing tests that pay for themselves — what to test, when to test, how to test incoming and outgoing messages, and keeping the test suite cheap to maintain as the design evolves.

Tony Duong

Jul 17, 2026・6 min

Day 58

Read chapter 8 of Practical Object-Oriented Design in Ruby (composition), and built an n8n workflow that posts a daily Japanese kanji lesson to social media.

Tony Duong

Jul 16, 2026・1 min

POODR Chapter 8: Combining Objects with Composition

Building objects out of parts — composition vs inheritance, the has-a relationship, modeling with factories and roles, and how to choose between inheritance, modules, and composition.

Tony Duong

Jul 16, 2026・6 min

Day 57

Read Practical Object-Oriented Design in Ruby by Sandi Metz through chapter 7 (with a summary per chapter), and finally arrived in France, settling in Toulouse.

Tony Duong

Jul 15, 2026・1 min

POODR Chapter 1: Object-Oriented Design

Why design matters — the true cost of change, treating software as an arrangement of message-passing objects, and design as the art of managing dependencies.

Tony Duong

Jul 15, 2026・4 min

POODR Chapter 2: Designing Classes with a Single Responsibility

Making classes do one thing — the SRP, the TRUE test, hiding instance variables behind methods, and isolating data structures so change stays cheap.

Tony Duong

Jul 15, 2026・5 min

POODR Chapter 3: Managing Dependencies

Recognizing, isolating, and inverting dependencies — dependency injection, depending on abstractions, and choosing the direction dependencies should point.

Tony Duong

Jul 15, 2026・5 min

POODR Chapter 4: Creating Flexible Interfaces

Designing the messages between objects — public vs private interfaces, asking for 'what' not 'how', context independence, and the Law of Demeter.

Tony Duong

Jul 15, 2026・5 min

POODR Chapter 5: Reducing Costs with Duck Typing

Across-class interfaces defined by behavior, not class — recognizing hidden ducks behind case-on-class and responds_to? checks, and trusting objects by what they do.

Tony Duong

Jul 15, 2026・4 min

POODR Chapter 6: Acquiring Behavior Through Inheritance

Classical inheritance done right — recognizing where it fits, refactoring concrete classes into an abstract superclass, and using the template method pattern with hooks instead of super.

Tony Duong

Jul 15, 2026・6 min

POODR Chapter 7: Sharing Role Behavior with Modules

Sharing behavior across unrelated classes with Ruby modules — recognizing roles, writing inheritable module code, understanding method lookup, and the rules of well-behaved inheritance (Liskov, hooks, shallow hierarchies).

Tony Duong

Jul 15, 2026・5 min

Day 56

Last week as a permanent Spacely employee — traveled from Karatsu to Tokyo for final goodbyes, received a lovely yosegaki from colleagues, and shipped a Notion + Slack release-tracking automation for the CS team.

Tony Duong

Jul 4, 2026・1 min

Day 55

Busy packing for the move to France — little study time; Tokyo next week for last goodbyes before leaving Japan.

Tony Duong

Jun 28, 2026・1 min

Day 54

Added a Tasks tab to Spacely's Sprint Charts Jira app — export engineer tasks with health vs development ratios by issue-key category.

Tony Duong

Jun 23, 2026・1 min

Building an AI Clone Chatbot from Markdown

How I built a recruiter-facing digital clone on this blog — persona files, a post digest, lightweight RAG, streaming Claude responses, and why I skipped a vector database.

Tony Duong

Jun 22, 2026・16 min

Day 53

Wrote a deep-dive on the AI clone chatbot, and watched Prof. Jiang Xueqin on why success is about class and game theory — not just willpower.

Tony Duong

Jun 22, 2026・1 min

Why Some People Become Successful — Prof. Jiang Xueqin

A lecture by Prof. Jiang Xueqin on the Marshmallow Test, growth mindset, and deliberate practice — and why correlation is not causation when it comes to success, parenting, and social mobility.

Tony Duong

Jun 22, 2026・6 min

Day 52

Built an Eve digest agent for Discord, wired Claude Code hooks on the backend repo, and watched Japan beat Tunisia 4-0 — rooting for France at this year's World Cup.

Tony Duong

Jun 21, 2026・3 min

Day 51

rails-openapi-generator $ref support, Claude Code hooks presentation, and Shirimono IAP submission rejected by App Store review — retrying tomorrow.

Tony Duong

Jun 20, 2026・1 min

Day 50

Announced I'm leaving Spacely as a full-time employee — lovely company and colleagues, heading back to France for a new chapter while staying on part-time.

Tony Duong

Jun 19, 2026・1 min

Beginner System Design Interview: Design Bitly w/ a Ex-Meta Staff Engineer

Hello Interview's beginner walkthrough of designing Bitly — requirements, core entities, API, counter vs hash short-code generation, base62, 301 vs 302 redirects, read/write split, Redis cache, and CAP.

Tony Duong

Jun 17, 2026・5 min

Day 49

France's World Cup opener, a Spacely Jira app for velocity charts, and Hello Interview's beginner Bitly system design walkthrough.

Tony Duong

Jun 17, 2026・1 min

Day 48

Watched Boris Cyrulnik on decivilization and fixed Shirimono Apple auth after a Hetzner migration — PEM newlines stored as literal \n.

Tony Duong

Jun 16, 2026・1 min

Family, School, Screens — Boris Cyrulnik's Warning

Psychiatrist Boris Cyrulnik on decivilization — culture vs civilization, the first 1000 days, screen time and depression, family ruptures, and reinventing rituals of empathy.

Tony Duong

Jun 16, 2026・6 min

Chapter 5: Spacely

A bicycle from Tokyo to Osaka, snow I didn't plan for, and then Spacely — a Japanese VR platform, a four-person backend team, a Rails upgrade that taught me the whole codebase, a core job made 4× faster, Honeybadger alerts cut from 10k to under 300, and becoming Tech Lead. A year and a half that felt like four. And then France.

Tony Duong

Jun 15, 2026・9 min

Off the worker, into Lambda: making 360° cubemap generation ~4× faster

How we moved a CPU-bound 360°-to-cubemap conversion off our shared Sidekiq workers and onto AWS Lambda, picked py360convert over krpano, right-sized Lambda memory, and got a ~4× end-to-end speedup with stable latency.

Tony Duong

Jun 15, 2026・13 min

Day 47

Made Shirimono free for all — replaced subscriptions with tips and migrated Stripe and RevenueCat from recurring to one-time payments.

Tony Duong

Jun 14, 2026・1 min

A House That Creates Circulation — Permaculture Designer Yotsui Shinji

Permaculture designer Yotsui Shinji on designing a home and farm as one living system — compost loops, soil creation, solar backup, and a home as a tool for life.

Tony Duong

Jun 13, 2026・4 min

Day 46

Presented image-processing speedup work, watched permaculture and ad-click-aggregator system design videos — planning a hands-on Kinesis implementation.

Tony Duong

Jun 13, 2026・1 min

System Design Interview: Design an Ad Click Aggregator w/ a Ex-Meta Staff Engineer

Hello Interview's walkthrough of designing an ad click aggregator — infrastructure-design flow, Kinesis + Flink stream aggregation, Cassandra/OLAP query path, hot-shard mitigation, and periodic reconciliation.

Tony Duong

Jun 13, 2026・5 min

Day 45

Watched two Hello Interview videos — designing Dropbox / Google Drive and Kafka vs RabbitMQ — and set up a Datadog Bits AI agent to send a daily application-health report.

Tony Duong

Jun 11, 2026・1 min

Kafka vs RabbitMQ

Hello Interview on choosing between Kafka and RabbitMQ — smart broker vs smart consumer, queue vs append-only log, and the ordering, throughput, delivery, and ops trade-offs that should drive the decision.

Tony Duong

Jun 11, 2026・6 min

System Design Interview: Design Dropbox or Google Drive w/ a Ex-Meta Staff Engineer

Hello Interview's walkthrough of designing Dropbox / Google Drive — presigned-URL uploads direct to S3, chunking with fingerprints for resumable uploads, and syncing via polling, delta sync, and reconciliation.

Tony Duong

Jun 11, 2026・6 min

Chapter 4: Learning to Lead

Monstarlab — a global consulting firm, a remote desk in Enoshima, a different client every time. A Christmas spent recovering production data, a pile of AWS certifications, a chatbot built in Terraform, a promotion to Tech Lead, and eight engineers in Da Nang who taught me what leading actually costs.

Tony Duong

Jun 9, 2026・11 min

Day 44

Finished writing about a 4× worker speedup (Japanese only for now) and added Chapter 4 of my career story — Monstarlab, AWS, and learning to lead.

Tony Duong

Jun 9, 2026・1 min

Day 43

Organized ~120 Datadog monitors, finished the last chapter of DDIA, watched a system-design walkthrough on Uber plus videos on success and minimalism — and made a big decision: moving back to Toulouse after 8 years in Japan.

Tony Duong

Jun 7, 2026・2 min

Success Is Not About Trying Hard

Why success comes from deliberate consistency mixed with randomness, intuition, and reflection — not brute effort — with examples from exams, gaming, and YouTube.

Tony Duong

Jun 7, 2026・4 min

System Design Interview: Design Uber w/ a Ex-Meta Staff Engineer

Hello Interview's walkthrough of designing Uber — the hardest of the proximity-search problems — covering quad-tree geospatial indexing, taming location-update throughput, and consistent driver matching.

Tony Duong

Jun 7, 2026・4 min

Why I Live a Simple Minimalist Life

Theo, a former jeweller who now owns 9.6 kg of possessions and lives by volunteering in gardens, reflects on minimalism, integrity, hope, and joy.

Tony Duong

Jun 7, 2026・4 min

Day 42

Learned virtual waiting queues, back-of-the-envelope estimation, Ruby observers, and server-side events — then built a repo to learn SSE hands-on with AI-authored chapters.

Tony Duong

Jun 6, 2026・1 min

Day 41

Watched Hello Interview's Ticketmaster system design walkthrough — enjoying the channel's clear explanations and seeing ideas connect with DDIA.

Tony Duong

Jun 5, 2026・1 min

System Design Interview: Design Ticketmaster w/ a Ex-Meta Staff Engineer

Notes from Hello Interview on designing Ticketmaster — no double booking, two-phase reserve/confirm, Redis TTL locks, Elasticsearch + CDC, virtual waiting queue for surges, and CAP trade-offs per path.

Tony Duong

Jun 5, 2026・6 min

Day 40

Watched Manning on software architecture trade-offs and started (but did not finish) DDIA Chapter 12 on the future of data systems.

Tony Duong

Jun 4, 2026・1 min

DDIA Chapter 12: The Future of Data Systems

Notes on the final DDIA chapter — integrating batch and stream processing, unbundling databases, end-to-end correctness, and the ethics of data-intensive systems.

Tony Duong

Jun 4, 2026・4 min

Grokking Software Architecture: It's All About Tradeoffs

Notes from Manning on Matt Erman's Grokking Software Architecture — the three A's (awareness, alignment, accountability), trade-offs under pressure, the clarity engineer process, and the Friendster lesson on wrong architectural priorities.

Tony Duong

Jun 4, 2026・5 min

Day 39

Watched Hello Interview's Twitter system design walkthrough — straight to the point on NoSQL for read/write-heavy low-latency tweet storage.

Tony Duong

Jun 3, 2026・1 min

System Design Interview Walkthrough: Design Twitter

Notes from Hello Interview on designing Twitter — microservices, MongoDB for tweet CRUD, fan-out on write timelines, graph DB for social graph, Elasticsearch search, and when NoSQL fits read/write-heavy low-latency workloads.

Tony Duong

Jun 3, 2026・4 min

Day 38

Watched Hello Interview on distributed transactions (2PC vs Saga) and read DDIA Chapter 11 on stream processing.

Tony Duong

Jun 2, 2026・1 min

DDIA Chapter 11: Stream Processing

Notes on stream processing in Designing Data-Intensive Applications — event streams, message brokers, CDC, event sourcing, time semantics, stream joins, and fault tolerance.

Tony Duong

Jun 2, 2026・7 min

Distributed Transactions Explained: 2 Phase Commit vs Saga Pattern

Notes from Hello Interview on distributed transactions — when single-DB ACID breaks across services, why 2PC blocks at scale, and how Saga (choreography vs orchestration) with compensations and transactional outbox works in production.

Tony Duong

Jun 2, 2026・6 min

Day 37

Published the JLPT N2 course to Shirimono and watched a neuroscience conversation on the meaning of life.

Tony Duong

Jun 1, 2026・1 min

The meaning of life, explained by neuroscience — with Albert Moukheiber

Notes from a Les Lueurs conversation with neuroscientist Albert Moukheiber: there is no hidden meaning of life to find, we invent it, and most of the self-help promises around it don't survive contact with how the brain actually works.

Tony Duong

Jun 1, 2026・5 min

Building a Chat: Chapter 1 — Architecture and Setup

Two separate apps, four core concepts, and getting Rails ActionCable talking to Next.js over WebSockets.

Tony Duong

May 31, 2026・7 min

Building a Chat: Chapter 2 — The ActionCable Backend

Connection authentication, visitor and admin channels, the data model, and how Solid Cable replaces Redis with SQLite.

Tony Duong

May 31, 2026・7 min

Building a Chat: Chapter 3 — The Frontend Client

TypeScript ActionCable client, discriminated unions for channel data, React WebSocket lifecycle, and the useRef trap that prevents infinite reconnections.

Tony Duong

May 31, 2026・7 min

Building a Chat: Chapter 4 — Admin Dashboard and Push Notifications

Admin authentication, managing multiple conversations over one WebSocket, and the full Web Push notification pipeline from VAPID keys to the service worker.

Tony Duong

May 31, 2026・6 min

Building a Chat: Chapter 5 — Deployment with Kamal

Docker multi-stage build, Kamal 2 deployment to Hetzner, secrets management, GitHub Actions CI/CD, and production WebSocket wiring.

Tony Duong

May 31, 2026・5 min

Day 36

Finished the roadmap.sh Ruby roadmap, built an AI prompt that teaches a codebase as a chapter-based book, watched interviews on happiness and message queues in system design.

Tony Duong

May 31, 2026・1 min

Message Queues in System Design Interviews w/ Meta Staff Engineer

Notes from Hello Interview on message queues for system design interviews — motivating example, acks, delivery guarantees, scaling, back pressure, ordering, poison messages, DLQs, and Kafka vs SQS vs RabbitMQ.

Tony Duong

May 31, 2026・5 min

Professeur de bonheur: is happiness genetic, and how to be happier

Notes from a Légende interview with positive-psychology specialist Florence Servan-Schreiber on the science of happiness and practical techniques to feel better day to day.

Tony Duong

May 31, 2026・5 min

Champions League Final: PSG vs Arsenal

Went to the cinema to watch the Champions League final — Paris Saint-Germain vs Arsenal. What a game!

Tony Duong

May 30, 2026・1 min

Day 35

Added a real-time chat feature to the blog using Rails ActionCable and WebSockets.

Tony Duong

May 29, 2026・1 min

Day 34

Reworked Shirimono's public pages for a much more polished, eye-catching look.

Tony Duong

May 28, 2026・1 min

Chapter 3: Learning to Build Well

Two and a half years at Overflow — a Tokyo startup, a Slack cron job, a mentor named Ohtani-san, the AWS vocabulary I never had, a couple of Stripe side projects, and the restlessness that eventually walked me into Monstarlab.

Tony Duong

May 27, 2026・9 min

Chapter 1: From Montreal to Tokyo

Two years in Montreal, a stack of weekend gamejams, a VR internship — and then a random Facebook ad that sent me to Japan instead of staying in Canada.

Tony Duong

May 26, 2026・6 min

Chapter 2: Landing in Japan

Tokyo, February 2018. A sharehouse in Kami-Itabashi, a seven-person company called Seido, and a blank-sheet stretch of building everything from scratch — until the doubt set in.

Tony Duong

May 26, 2026・7 min

Day 33

Discovered roadmap.sh and subscribed for structured learning, starting with the AI engineer course; also started a new collection writing the story of my career, beginning with Montreal to Tokyo.

Tony Duong

May 26, 2026・1 min

Day 32

Finished the second half of Ansh Lamba's 6-hour Apache Spark deep-dive.

Tony Duong

May 25, 2026・1 min

Apache Spark — The Ultimate Guide (notes)

Notes from a 6-hour Apache Spark deep-dive by Ansh Lamba — distributed computing fundamentals, architecture, DataFrames, joins, memory management, caching, partition pruning, and AQE.

Tony Duong

May 24, 2026・10 min

Day 31

A Claude Code skill for Rails upgrades, the first half of a 6-hour Apache Spark deep-dive, and a streaming Claude-powered chat at /en/chat.

Tony Duong

May 24, 2026・1 min

Day 30

Read DDIA Chapter 10 on batch processing and built a small repo to learn Apache Spark hands-on.

Tony Duong

May 23, 2026・1 min

DDIA Chapter 10: Batch Processing (Made Simple)

A friendly walkthrough of batch processing in Designing Data-Intensive Applications — Unix pipes, MapReduce, and the rise of Apache Spark.

Tony Duong

May 23, 2026・6 min

Day 28

building my own Rails gem to auto-generate OpenAPI documentation, implemented with spec-kit

Tony Duong

May 19, 2026・1 min

Day 27

Built a custom Jira Forge sprint-charts app, added CloudFront for Shirimono public assets, and published public pages for all Japanese language resources.

Tony Duong

May 18, 2026・1 min

Day 26

Built a first Ruby MCP server for answering profile questions from Markdown files and started learning the repo through an AI-written teach-me book.

Tony Duong

May 12, 2026・1 min

Day 25

Read DDIA Chapter 9 on consistency and consensus and wrote a beginner-friendly summary.

Tony Duong

May 11, 2026・1 min

DDIA Chapter 9: Consistency and Consensus (Made Simple)

An easy-to-understand walkthrough of the hardest chapter in Designing Data-Intensive Applications — how distributed systems agree on what's true.

Tony Duong

May 11, 2026・6 min

Day 24

migrated Shirimono's backend from Render to Hetzner with Kamal — saved ~$60/month

Tony Duong

May 10, 2026・1 min

Saving ~$60/month by moving from Render to Hetzner with Kamal

Migrated Shirimono's Rails 8 backend from Render to a single Hetzner CPX21 with Kamal. Bill dropped from ~$70 to ~$9 per month. The setup, the cost math, and the four gotchas that ate most of the cutover window.

Tony Duong

May 10, 2026・7 min

Day 23

wrote an article about a lost update bug in spacely_web that had been unsolved for years

Tony Duong

Apr 15, 2026・1 min

Lost Updates in a Rails App: What Broke, How We Fixed It, and How We Tested It

A real lost update bug in a Rails app: two jobs merging different keys into the same JSON column drop one another, and how with_lock plus a threaded RSpec reproduce and fix it.

Tony Duong

Apr 15, 2026・6 min

Day 22

Read DDIA chapter 8, summarized two distributed-systems videos, and completed my first AWS Skill Builder course on spec-driven development with Kiro.

Tony Duong

Apr 14, 2026・1 min

DDIA Chapter 8: The Trouble with Distributed Systems (Summary)

A practical summary of DDIA chapter 8 covering partial failures, unreliable networks, clock assumptions, and reliability patterns for production systems.

Tony Duong

Apr 14, 2026・3 min

Failure is unavoidable! Designing Data-Intensive Apps chapter 8

Live-stream notes on DDIA chapter 8 covering partial failure, network uncertainty, transaction boundaries, and reliability-first design choices.

Tony Duong

Apr 14, 2026・2 min

Spec-Driven Development with Kiro: Features and Capabilities

Notes from my first AWS Skill Builder course, summarizing Kiro's spec-driven workflow, core feature set, and practical use cases.

Tony Duong

Apr 14, 2026・4 min

Today

A short note from today.

Tony Duong

Apr 14, 2026・1 min

What Is Checksum: The Easiest Explanation You'll Ever See

A concise video summary of what checksums are, how sender/receiver verification works, and where checksums are used in real systems.

Tony Duong

Apr 14, 2026・2 min

Day 21

DDIA chapter 7/8 study, concurrency testing practice, AWS architecture notes, and AI adoption mindset for developers.

Tony Duong

Apr 13, 2026・2 min

Transactions, ACID, and Isolation Levels — DDIA Chapter 7 (Video)

Live stream walkthrough of DDIA Chapter 7: why transactions matter, ACID, isolation levels and naming pitfalls, Postgres MVCC and vacuum, and MySQL/InnoDB undo logs.

Tony Duong

Apr 13, 2026・3 min

DDIA Chapter 7: Transactions

Summary of Kleppmann's chapter on transactions: ACID, isolation anomalies, snapshot isolation, two-phase locking, and serializable snapshot isolation.

Tony Duong

Apr 13, 2026・5 min

DDIA Chapter 8: The Trouble with Distributed Systems

In-progress notes on DDIA Chapter 8: partial failures, unreliable networks, time assumptions, and defensive patterns for distributed systems.

Tony Duong

Apr 13, 2026・2 min

Day 20

Glacier, Vertex TTS, Pokemon Go, and more DDIA ch.7 (transactions) — dense read, finishing tomorrow.

Tony Duong

Apr 12, 2026・1 min

Day 19

I passed the AWS Certified CloudOps Engineer - Associate and read how Vercel reduces code review time with AI in their monorepo.

Tony Duong

Apr 8, 2026・1 min

Day 18

I learned about the TestProf gem for profiling Ruby tests; a colleague used it to analyze factory usage and cut suite time about 20% (14 minutes to 11 minutes).

Tony Duong

Mar 30, 2026・1 min

AWS DataSync and AWS Backup: Disaster Recovery Notes

CloudOps exam notes on AWS DataSync (agents, NFS/SMB/HDFS, S3/EFS/FSx targets, schedules, metadata, Snowcone) and AWS Backup (backup plans, cross-region/account, vault lock WORM, console workflow).

Tony Duong

Mar 29, 2026・5 min

AWS IAM Identity: Permission Boundaries, Federation, STS, and Access Tools

CloudOps exam notes on IAM permission boundaries vs identity policies and SCPs, Credentials Report and Access Advisor, IAM Access Analyzer, STS (AssumeRole, SAML, web identity, MFA), enterprise vs app federation (SAML, custom broker, Cognito), and the IAM policy simulator.

Tony Duong

Mar 29, 2026・8 min

Amazon Route 53: Registrar Delegation, Resolver, Logging, and Governance

CloudOps exam notes on separating registrar from DNS, delegating NS to Route 53, S3 static website aliases, hybrid DNS with Resolver endpoints, cross-account private hosted zones, query logging, Resolver DNS Firewall, ARC, Route 53 Profiles, and cost cleanup.

Tony Duong

Mar 29, 2026・6 min

Amazon Route 53: DNS Fundamentals, Records, TTL, and Alias vs CNAME

CloudOps exam notes on DNS resolution and terminology, Route 53 as authoritative DNS and registrar, A/AAAA/CNAME/NS, email records (MX, TXT/SPF/DKIM/DMARC), TTL tradeoffs, and Route 53 alias records for ALB and zone apex.

Tony Duong

Mar 29, 2026・8 min

Amazon Route 53: Routing Policies, Health Checks, and Traffic Flow

CloudOps exam notes on Route 53 routing policies (simple, weighted, latency, failover, geolocation, geoproximity, multi-value, IP-based), health checks and calculated checks, CloudWatch for private targets, and Traffic Flow policies.

Tony Duong

Mar 29, 2026・7 min

AWS Security, Compliance, Encryption, and Secrets for CloudOps

CloudOps exam notes on WAF, Shield, Firewall Manager, Inspector, logging with Athena, GuardDuty, Macie, Trusted Advisor, Security Hub, Audit Manager, KMS (rotation, MRK, deletion), ACM, and Secrets Manager vs Parameter Store.

Tony Duong

Mar 29, 2026・11 min

Day 17

I studied CloudOps DR, security/compliance, IAM identity, and Route 53 in three parts (fundamentals, routing policies and health checks, then delegation resolver logging firewall arc profiles) and wrote six collection notes.

Tony Duong

Mar 29, 2026・2 min

Vertex AI Gen AI evaluation in the Google Cloud console

Screenshots of the Vertex AI Gen AI evaluation UI: dataset view with General Quality pass rates, plus a per-criterion drill-down with pass/fail reasons on a recipe-to-shopping-list task.

Tony Duong

Mar 29, 2026・2 min

Amazon S3 Introduction: Buckets, Objects, Security, and Versioning

Section 10 S3 notes through advanced topics: MFA delete, access logs, Object Lock and Glacier Vault Lock, VPC endpoints, Access Analyzer, plus replication, lifecycle, events, performance, batch, inventory, and Athena.

Tony Duong

Mar 28, 2026・22 min

AWS CloudFront and Global Accelerator: CDN, Caching, Origins, and Edge Networking

Exam-oriented notes on CloudFront as a CDN, origins (S3 OAC, VPC, custom HTTP), caching and invalidation, Origin Shield, geo restrictions, logging and reports, ALB sticky sessions, and Global Accelerator vs CloudFront.

Tony Duong

Mar 28, 2026・8 min

AWS Observability and Governance: CloudWatch, EventBridge, CloudTrail, and Config

CloudOps notes on CloudWatch, EventBridge (CloudTrail API patterns, Pipes, DLQ), Service Quotas, CloudTrail (digest integrity, org trails, EventBridge latency), and AWS Config (rules, aggregators, SSM remediation, vs CloudWatch and CloudTrail).

Tony Duong

Mar 28, 2026・22 min

AWS Account Management: Health Dashboard, Organizations, SCPs, and Control Tower

CloudOps notes on AWS Health (service vs account vs org views, EventBridge automation), AWS Organizations (OUs, consolidated billing, SCPs, RI sharing, PrincipalOrgID), and Control Tower landing zones and guardrails.

Tony Duong

Mar 28, 2026・6 min

AWS RDS, Aurora, RDS Proxy, and ElastiCache

Managed SQL and caching for CloudOps: RDS/Aurora (including Serverless and Global Database), RDS Proxy, and ElastiCache Redis/Memcached scaling, patterns, and metrics.

Tony Duong

Mar 28, 2026・16 min

AWS Service Catalog, Billing Alarms, Cost Explorer, Budgets, and Cost Tools

CloudOps notes on AWS Service Catalog (products, portfolios, sharing, TagOptions), CloudWatch billing metrics in us-east-1, Cost Explorer, Budgets with actions, cost allocation tags, CUR, Compute Optimizer, and Billing Conductor.

Tony Duong

Mar 28, 2026・6 min

Day 16

I mixed AWS CloudOps notes, a Vertex AI eval side project, and French localization work on Shirimono

Tony Duong

Mar 28, 2026・3 min

AWS Lambda Fundamentals, Integrations, and Pricing

A practical summary of AWS Lambda core concepts, pricing model, and common integrations like EventBridge and S3.

Tony Duong

Mar 27, 2026・4 min

Day 15

I continued preparing for next Saturday's AWS certification exam by reviewing Lambda, EBS, and EFS with practical notes and comparisons.

Tony Duong

Mar 27, 2026・1 min

EBS and EFS Core Concepts and Exam Notes

A practical exam-focused summary of EBS volumes, snapshots, EFS file systems, and when to choose each for AWS workloads.

Tony Duong

Mar 27, 2026・5 min

Day 14

Shirimono shipped on the App Store, fixed unstubbed `sleep` in tests, and finished the EC2 High Availability and Scalability section for AWS CloudOps Developer.

Tony Duong

Mar 26, 2026・1 min

Day 13

Git fundamentals video; continued AWS CloudOps Engineer Associate prep — practiced ALB hands-on demo.

Tony Duong

Mar 23, 2026・1 min

Git Will Finally Make Sense After This

Video explaining Git fundamentals from first principles: commits as snapshots, DAG structure, branches as pointers, HEAD, detached HEAD, three areas (working/staging/repo), and undo commands.

Tony Duong

Mar 23, 2026・4 min

Day 12

Finishing touches for Shirimono app store submission — refactoring and UI improvements.

Tony Duong

Mar 22, 2026・1 min

Hands-On Demo: AWS Application Load Balancer

Step-by-step: launch EC2 instances, create an ALB with a target group, verify load balancing and health checks (stop/start instance). Includes NLB hands-on.

Tony Duong

Mar 21, 2026・4 min

AWS Application Load Balancer (ALB) — Deep Dive

Layer 7 HTTP load balancer: target groups, routing rules (path, host, query string, headers), X-Forwarded-* headers, health checks, metrics, and weighted target groups.

Tony Duong

Mar 21, 2026・4 min

AWS Elastic Load Balancer (ELB) Explained

Overview of AWS load balancers: role, benefits, health checks, four types (CLB, ALB, NLB, GWLB), security groups, sticky sessions, and TLS.

Tony Duong

Mar 21, 2026・5 min

Scalability and High Availability Explained

Accessible overview of vertical vs horizontal scaling and high availability, with a call-center analogy and AWS examples (EC2, RDS Multi-AZ, Auto Scaling).

Tony Duong

Mar 21, 2026・5 min

Day 11

Continued AWS Certified ZCloudOps prep: consolidated notes on EC2 scalability, high availability, ELB/ALB architecture, and ALB hands-on practice.

Tony Duong

Mar 21, 2026・1 min

Day 10

Tony Duong

Mar 20, 2026・1 min

Books That Made Me A CRACKED Backend Dev

Video listing seven books that helped level up backend skills: Clean Code, The Pragmatic Programmer, DDIA, System Design Interview, Database Internals, Release It, and Fundamentals of Software Architecture.

Tony Duong

Mar 19, 2026・3 min

Day 9

Watched DDIA Ch.6 sharding; interview prep; seven backend books; SSH in 2 min; why devs need git worktree (especially with AI agents).

Tony Duong

Mar 19, 2026・1 min

Database Sharding! Designing Data-Intensive Applications Chapter 6

Video walkthrough of DDIA Chapter 6 on partitioning (sharding): diagrams and explanations of key-range vs hash partitioning, secondary indexes, rebalancing, and request routing.

Tony Duong

Mar 19, 2026・2 min

Devs Can No Longer Avoid Learning Git Worktree

Video on why git worktree matters: multiple working directories from one repo for context switching, hotfixes, PR review, and especially running agentic AI in a separate worktree so you can keep working.

Tony Duong

Mar 19, 2026・2 min

How to Pass Technical Interviews Without Grinding LeetCode

Video on a smarter approach to technical interview prep: focus on 15–20 core patterns instead of hundreds of random LeetCode problems; the speaker got hired at Microsoft with this method.

Tony Duong

Mar 19, 2026・2 min

SSH Explained in 2 Minutes!

Short video on SSH (Secure Shell): protocol for secure remote access, encrypted channel, client/server model, and password vs key-based authentication.

Tony Duong

Mar 19, 2026・2 min

Day 8

Watched MIT/Anthropic on AI coding limits; read DDIA chapter 6 on partitioning; added collections to the site to better organize content.

Tony Duong

Mar 18, 2026・1 min

DDIA Chapter 6: Partitioning

Summary of Kleppmann's chapter on partitioning (sharding): splitting data across nodes, partition strategies, secondary indexes, rebalancing, and request routing.

Tony Duong

Mar 18, 2026・4 min

AWS Systems Manager notes (overview, Fleet Manager, DHMC, documents, Run Command, Session Manager, Automation, Parameter Store, Inventory, State Manager, Distributor, Patch Manager, Maintenance Windows, OpsCenter)

Condensed notes on AWS Systems Manager: agent, Fleet Manager, DHMC, documents, Run Command, Session Manager, Automation, Parameter Store, Inventory, State Manager, Distributor, Patch Manager, Maintenance Windows, OpsCenter (OpsItems, runbooks).

Tony Duong

Mar 17, 2026・22 min

Day 7

Continued AWS CloudOps study with AWS Systems Manager (overview, Fleet Manager, resource groups).

Tony Duong

Mar 17, 2026・1 min

AWS EC2 notes (launch, resize, placement, SSH, CloudWatch Agent, status checks, hibernate, Instance Scheduler, AMI, Image Builder)

Condensed notes on EC2: launch, resize, placement, SSH/Instance Connect, CloudWatch and agent, status checks, Hibernate, Instance Scheduler, AMI (create, No-Reboot, cross-account), EC2 Image Builder, AMI in production.

Tony Duong

Mar 16, 2026・12 min

Day 6

Watched DDIA Ch5 stream, continued AWS CloudOps (EC2 + AMI), wrote EC2 notes, used ilus.ai for Shirimono, found Claude March 2026 usage promo.

Tony Duong

Mar 16, 2026・1 min

Designing Data-Intensive Applications: Chapter 5

Notes from a live stream walking through DDIA Chapter 5 (Replication): single-leader setup, primary and read replicas, scaling reads, and high availability across availability zones.

Tony Duong

Mar 16, 2026・2 min

Day 5

Watched Claude 24/7 loops and scheduled tasks, read DDIA ch5, started Spacely blog migration (blocked by stale repo).

Tony Duong

Mar 15, 2026・1 min

DDIA Chapter 5: Replication

Summary of Kleppmann's chapter on replication in data systems: why replicate, single-leader, multi-leader, and leaderless replication, plus consistency trade-offs.

Tony Duong

Mar 15, 2026・4 min

How I Made a 24/7 AI Employee with Claude (Scheduled Tasks and Loops)

Notes on running Claude 24/7 via two methods: /loop in Claude Code (interval-based, technical) and Scheduled Tasks in the cloud desktop (set-and-forget, no-code).

Tony Duong

Mar 15, 2026・2 min

Day 4

Read DDIA ch4, built Claude SKILLS for Shirimono, and a CLI for Slack-based brag summaries (brag-slack-cli)

Tony Duong

Mar 14, 2026・6 min

DDIA Chapter 4: Encoding and Evolution

Summary of Kleppmann's chapter on data encoding formats, schema evolution, and compatibility in data-intensive systems.

Tony Duong

Mar 14, 2026・6 min

Day 3

Reviewed a PR with new tech, watched talks on spec-driven development and agent skills, read and watched DDIA chapter 3 content

Tony Duong

Mar 13, 2026・1 min

DDIA Chapter 3: Storage and Retrieval

How databases store and retrieve data — from log-structured engines (LSM-trees) to page-oriented engines (B-trees), plus indexing strategies, OLTP vs OLAP, and column-oriented storage.

Tony Duong

Mar 13, 2026・7 min

Designing Data-Intensive Applications: Chapter 3

Livestream walkthrough of DDIA Chapter 3 — visual explanations of row vs column storage, B-trees vs LSM trees, and why OLTP and OLAP databases are engineered differently.

Tony Duong

Mar 13, 2026・5 min

Don't Build Agents, Build Skills Instead

Notes on Anthropic's talk about agent skills — organized folders that package composable procedural knowledge, complementing MCP servers in the emerging general agent architecture.

Tony Duong

Mar 13, 2026・4 min

Spec-Driven Development: AI Assisted Coding Explained

Notes on spec-driven development — how writing specs before code reduces ambiguity and improves AI-assisted coding compared to vibe coding.

Tony Duong

Mar 13, 2026・3 min

Day 2

Set up Keystatic CMS, fixed i18n redirects, picked up Rails and Claude Code tips, and read DDIA Chapter 2.

Tony Duong

Mar 12, 2026・2 min

DDIA Chapter 2: Data Models and Query Languages

Notes on Chapter 2 of Designing Data-Intensive Applications — relational vs document models, query languages, and graph databases.

Tony Duong

Mar 12, 2026・4 min

How a Meta Staff Engineer Uses Claude Code: 50 Tips for Agentic Development

John Kim's comprehensive guide to moving from manual coding to agentic orchestration with Claude Code — covering setup, power commands, and advanced workflows.

Tony Duong

Mar 12, 2026・6 min

Day 1

Reading DDIA, slashing Honeybadger alerts, Claude Code Actions, AI Spec-Driven Development, and progress on Shirimono.

Tony Duong

Mar 11, 2026・1 min