https://albertoduran.com/thejournal/ Technical write-ups and project vaults by Alberto Duran on software architecture, AWS, Python, AI agents, and how this site is built. en Tue, 29 Sep 2026 00:00:00 GMT https://albertoduran.com/thejournal/aws_serverless_vod_manager/ https://albertoduran.com/thejournal/aws_serverless_vod_manager/ Tue, 29 Sep 2026 00:00:00 GMT How the video pipeline gained a Cognito-protected manager page, an HTTP API, a CORS fix only production could expose, and a public player. aws serverless api-gateway cognito cors https://albertoduran.com/thejournal/building_albertoduran/ https://albertoduran.com/thejournal/building_albertoduran/ Mon, 03 Aug 2026 00:00:00 GMT How albertoduran.com is built as a static-first Astro platform that compiles MDX, diagrams, and charts into inspectable files. astro architecture bloomwright cloudflare https://albertoduran.com/thejournal/building_albertoduran/authoring/ https://albertoduran.com/thejournal/building_albertoduran/authoring/ Mon, 03 Aug 2026 00:00:00 GMT Writing an article is really compiling one. The path a candidate MDX file takes from schema, through policy and routing, to a rendered page. mdx content astro https://albertoduran.com/thejournal/building_albertoduran/authoring/content_model/ https://albertoduran.com/thejournal/building_albertoduran/authoring/content_model/ Mon, 03 Aug 2026 00:00:00 GMT The live Zod schema every publication satisfies, the glob that hides partials, and the one field the schema accepts but the page never shows. content mdx astro https://albertoduran.com/thejournal/building_albertoduran/authoring/fences/ https://albertoduran.com/thejournal/building_albertoduran/authoring/fences/ Mon, 03 Aug 2026 00:00:00 GMT Why an author writes a fenced block instead of importing a component, how parity is guaranteed, and when to reach for the component after all. mdx daisyui bloomwright https://albertoduran.com/thejournal/building_albertoduran/authoring/manifest_policy/ https://albertoduran.com/thejournal/building_albertoduran/authoring/manifest_policy/ Mon, 03 Aug 2026 00:00:00 GMT The manifest is where publication policy lives. Draft scoping, the invariants a vault must satisfy, image inheritance, ordering, and the read-time formula. content astro architecture https://albertoduran.com/thejournal/building_albertoduran/authoring/mdx_pipeline/ https://albertoduran.com/thejournal/building_albertoduran/authoring/mdx_pipeline/ Mon, 03 Aug 2026 00:00:00 GMT The Markdown processor, why the fence integration registers before mdx, how Markdown elements become components, and how code gets two themes. mdx astro bloomwright https://albertoduran.com/thejournal/building_albertoduran/authoring/routing/ https://albertoduran.com/thejournal/building_albertoduran/authoring/routing/ Mon, 03 Aug 2026 00:00:00 GMT How a catch-all route turns published entries into a finite list of pages, and the shell of sidebars, dock, and overlays that surrounds every article. astro content architecture https://albertoduran.com/thejournal/building_albertoduran/bloomwright/ https://albertoduran.com/thejournal/building_albertoduran/bloomwright/ Mon, 03 Aug 2026 00:00:00 GMT Why albertoduran stopped owning its UI kit and render engines, and how it now consumes them as two versioned packages. bloomwright architecture astro https://albertoduran.com/thejournal/building_albertoduran/bloomwright/costs/ https://albertoduran.com/thejournal/building_albertoduran/bloomwright/costs/ Mon, 03 Aug 2026 00:00:00 GMT The counterweight to the extraction story: duplicated CSS (since retired), git-ref versioning, source-shipped compilation, and two build-only bugs. bloomwright css architecture https://albertoduran.com/thejournal/building_albertoduran/bloomwright/mdx_layer/ https://albertoduran.com/thejournal/building_albertoduran/bloomwright/mdx_layer/ Mon, 03 Aug 2026 00:00:00 GMT The integration that turns code fences into rendered output, why it registers before mdx, and why it no longer renders Mermaid itself. bloomwright mdx astro https://albertoduran.com/thejournal/building_albertoduran/bloomwright/seams/ https://albertoduran.com/thejournal/building_albertoduran/bloomwright/seams/ Mon, 03 Aug 2026 00:00:00 GMT Extraction worked because three decisions moved from the packages to the app: what publishes, where bytes are cached, and who renders. bloomwright architecture mermaid https://albertoduran.com/thejournal/building_albertoduran/bloomwright/ui_components/ https://albertoduran.com/thejournal/building_albertoduran/bloomwright/ui_components/ Mon, 03 Aug 2026 00:00:00 GMT The four component families, the pure logic layer that keeps fences and components identical, and why icons ship as props. bloomwright daisyui css https://albertoduran.com/thejournal/building_albertoduran/bloomwright/ui_render_core/ https://albertoduran.com/thejournal/building_albertoduran/bloomwright/ui_render_core/ Mon, 03 Aug 2026 00:00:00 GMT How a package that was meant to stay a dependency-free leaf deliberately reversed course and absorbed build-time rendering. bloomwright mermaid echarts https://albertoduran.com/thejournal/building_albertoduran/interface/ https://albertoduran.com/thejournal/building_albertoduran/interface/ Mon, 03 Aug 2026 00:00:00 GMT What the app still owns of its look, what bloomwright-ui now owns, and where the line between them falls after the UI kit moved out. css daisyui bloomwright https://albertoduran.com/thejournal/building_albertoduran/interface/build_time_data/ https://albertoduran.com/thejournal/building_albertoduran/interface/build_time_data/ Mon, 03 Aug 2026 00:00:00 GMT Consuming an unstable third-party source during the build, validating it like any other content, and letting the browser finish the one job the build cannot. astro content runtime https://albertoduran.com/thejournal/building_albertoduran/interface/css_architecture/ https://albertoduran.com/thejournal/building_albertoduran/interface/css_architecture/ Mon, 03 Aug 2026 00:00:00 GMT One global stylesheet imported in eleven numbered stages, the DaisyUI parts it opts into, and how the duplicated partials from the extraction were retired. css daisyui bloomwright https://albertoduran.com/thejournal/building_albertoduran/interface/portfolio_surfaces/ https://albertoduran.com/thejournal/building_albertoduran/interface/portfolio_surfaces/ Mon, 03 Aug 2026 00:00:00 GMT The surfaces outside the journal: project landing pages that act as vault front doors, and the recruiter-facing profile built from typed data. astro architecture content https://albertoduran.com/thejournal/building_albertoduran/interface/progressive_enhancement/ https://albertoduran.com/thejournal/building_albertoduran/interface/progressive_enhancement/ Mon, 03 Aug 2026 00:00:00 GMT Every browser enhancement improves a baseline that already renders. The custom elements that do it now ship from two repositories, and why failures stay local. runtime astro bloomwright https://albertoduran.com/thejournal/building_albertoduran/interface/reading_navigation/ https://albertoduran.com/thejournal/building_albertoduran/interface/reading_navigation/ Mon, 03 Aug 2026 00:00:00 GMT The app-owned reading experience: heading tracking with sticky offsets and page edges, the vault explorer tree, and previous-next pagination. runtime astro architecture https://albertoduran.com/thejournal/building_albertoduran/interface/theming/ https://albertoduran.com/thejournal/building_albertoduran/interface/theming/ Mon, 03 Aug 2026 00:00:00 GMT DaisyUI 5 OKLCH themes and semantic tokens, and the three separate moments a theme has to be correct, each owned by a different layer. css daisyui runtime https://albertoduran.com/thejournal/building_albertoduran/platform/ https://albertoduran.com/thejournal/building_albertoduran/platform/ Mon, 03 Aug 2026 00:00:00 GMT The system behind the site: what each repository owns, what is left in the app, and the single static artifact they all serve. architecture astro cloudflare https://albertoduran.com/thejournal/building_albertoduran/platform/delivery/ https://albertoduran.com/thejournal/building_albertoduran/platform/delivery/ Mon, 03 Aug 2026 00:00:00 GMT How the static build reaches Cloudflare Workers Static Assets, which caching and security headers it ships, and what the platform handles itself. cloudflare performance architecture https://albertoduran.com/thejournal/building_albertoduran/platform/repository_shape/ https://albertoduran.com/thejournal/building_albertoduran/platform/repository_shape/ Mon, 03 Aug 2026 00:00:00 GMT The app got smaller when the packages left. A tour of what remains in src, and one publication change traced through the boundaries that stayed. architecture astro bloomwright https://albertoduran.com/thejournal/building_albertoduran/platform/workspace/ https://albertoduran.com/thejournal/building_albertoduran/platform/workspace/ Mon, 03 Aug 2026 00:00:00 GMT The Node 22 devcontainer, how github dependencies resolve, and what a source-shipped package asks of the workspace that consumes it. astro bloomwright architecture https://albertoduran.com/thejournal/building_albertoduran/rendering/ https://albertoduran.com/thejournal/building_albertoduran/rendering/ Mon, 03 Aug 2026 00:00:00 GMT How the site turns diagrams and charts into static SVG at build time, and the rule that decides which tool draws what. mermaid echarts architecture https://albertoduran.com/thejournal/building_albertoduran/rendering/chart_gallery/ https://albertoduran.com/thejournal/building_albertoduran/rendering/chart_gallery/ Mon, 03 Aug 2026 00:00:00 GMT Every chart family rendered in a real article, with a note on the question each one answers, so an author can choose by looking at output. echarts charts mdx https://albertoduran.com/thejournal/building_albertoduran/rendering/echarts/ https://albertoduran.com/thejournal/building_albertoduran/rendering/echarts/ Mon, 03 Aug 2026 00:00:00 GMT How an ECharts options object becomes a server-rendered SVG at build time, how it is cached and emitted, and the five ways it can wake up. echarts performance astro https://albertoduran.com/thejournal/building_albertoduran/rendering/fallbacks/ https://albertoduran.com/thejournal/building_albertoduran/rendering/fallbacks/ Mon, 03 Aug 2026 00:00:00 GMT The provider chain that keeps a render outage from ever crashing a build, and the fixture mode that keeps tests offline. mermaid cloudflare testing https://albertoduran.com/thejournal/building_albertoduran/rendering/mermaid_pipeline/ https://albertoduran.com/thejournal/building_albertoduran/rendering/mermaid_pipeline/ Mon, 03 Aug 2026 00:00:00 GMT The build integration that finds diagrams, batches them, checks a cache, renders the misses, and writes themed SVG assets. mermaid astro performance https://albertoduran.com/thejournal/building_albertoduran/rendering/render_service/ https://albertoduran.com/thejournal/building_albertoduran/rendering/render_service/ Mon, 03 Aug 2026 00:00:00 GMT The full round trip from the build to the Cloudflare Worker and back, what happens inside while the build waits, and two live mismatches. mermaid cloudflare architecture https://albertoduran.com/thejournal/building_albertoduran/rendering/svg_transform/ https://albertoduran.com/thejournal/building_albertoduran/rendering/svg_transform/ Mon, 03 Aug 2026 00:00:00 GMT The HAST pass that strips scripts, rewrites ids, scopes CSS, and merges light and dark into one asset, plus the palette that survives the network. mermaid css architecture https://albertoduran.com/thejournal/building_albertoduran/rendering/why_a_worker/ https://albertoduran.com/thejournal/building_albertoduran/rendering/why_a_worker/ Mon, 03 Aug 2026 00:00:00 GMT The site deploys to Cloudflare, so why is there a second Cloudflare thing? The four-part answer, and the honest counterweights. mermaid cloudflare architecture https://albertoduran.com/thejournal/aws_serverless_vod/ https://albertoduran.com/thejournal/aws_serverless_vod/ Sat, 04 Jul 2026 00:00:00 GMT A serverless AWS pipeline that turns private recordings into HLS playback with MediaConvert, S3, Lambda, EventBridge, and CloudFront. aws serverless video cloudfront https://albertoduran.com/thejournal/is-oracle-stock-undervalued/ https://albertoduran.com/thejournal/is-oracle-stock-undervalued/ Wed, 01 Jul 2026 00:00:00 GMT Oracle trades at a deep discount to its intrinsic value despite high debt and negative free cash flow from AI infrastructure investments orcl oracle stock-analysis software-infrastructure https://albertoduran.com/thejournal/three-projects-one-pipeline/ https://albertoduran.com/thejournal/three-projects-one-pipeline/ Wed, 01 Jul 2026 00:00:00 GMT How three standalone tools, the Equity Valuation Engine, Equilyze, and Pressroom, turn a stock ticker into a finished article. pipeline architecture local-ai composition https://albertoduran.com/thejournal/langchain_ollama/ https://albertoduran.com/thejournal/langchain_ollama/ Tue, 23 Jun 2026 00:00:00 GMT Build a local LangChain chat project with Ollama, from environment setup to a working terminal conversation loop. langchain ollama python local-ai https://albertoduran.com/thejournal/equity_valuation_engine/ https://albertoduran.com/thejournal/equity_valuation_engine/ Sat, 20 Jun 2026 00:00:00 GMT Years of conservative investing led me to build a Python engine for studying company valuations with visible assumptions, model checks, and limits. project python valuation https://albertoduran.com/thejournal/equity_valuation_engine/assumptions_and_scenarios/ https://albertoduran.com/thejournal/equity_valuation_engine/assumptions_and_scenarios/ Sat, 20 Jun 2026 00:00:00 GMT Learn how historical signals, configured limits, and scenario policy become Bear, Base, and Bull paths without pretending to predict. valuation finance scenarios https://albertoduran.com/thejournal/equity_valuation_engine/choosing_a_valuation_model/ https://albertoduran.com/thejournal/equity_valuation_engine/choosing_a_valuation_model/ Sat, 20 Jun 2026 00:00:00 GMT Match DCF, multiples, dividends, assets, and reverse DCF to the financial shape of a business before trusting any estimate. valuation finance models https://albertoduran.com/thejournal/equity_valuation_engine/dcf_and_reverse_dcf/ https://albertoduran.com/thejournal/equity_valuation_engine/dcf_and_reverse_dcf/ Sat, 20 Jun 2026 00:00:00 GMT Build a discounted cash-flow valuation, inspect its sensitivity, and reverse the calculation to understand market-implied expectations. valuation dcf finance https://albertoduran.com/thejournal/equity_valuation_engine/extending_the_engine/ https://albertoduran.com/thejournal/equity_valuation_engine/extending_the_engine/ Sat, 20 Jun 2026 00:00:00 GMT Trace the architecture behind data fields, diagnostics, suitability, valuation managers, CLI output, JSON, and tests before adding features. python architecture valuation https://albertoduran.com/thejournal/equity_valuation_engine/first_valuation_run/ https://albertoduran.com/thejournal/equity_valuation_engine/first_valuation_run/ Sat, 20 Jun 2026 00:00:00 GMT Install the equity valuation engine, run one ticker, and learn to read suitability checks, scenarios, skipped models, and JSON. python valuation tutorial https://albertoduran.com/thejournal/equity_valuation_engine/other_valuation_models/ https://albertoduran.com/thejournal/equity_valuation_engine/other_valuation_models/ Sat, 20 Jun 2026 00:00:00 GMT Compare P/E, EV/EBITDA, P/S, ROE, DDM, and NAV through independent examples, and learn why every model needs its own guardrails. valuation multiples finance https://albertoduran.com/thejournal/equity_valuation_engine/reading_the_results/ https://albertoduran.com/thejournal/equity_valuation_engine/reading_the_results/ Sat, 20 Jun 2026 00:00:00 GMT Interpret scenario rows, skipped models, the equal-weight composite, model dispersion, and JSON without turning output into a target price. valuation json analysis https://albertoduran.com/thejournal/equity_valuation_engine/trusting_the_inputs/ https://albertoduran.com/thejournal/equity_valuation_engine/trusting_the_inputs/ Sat, 20 Jun 2026 00:00:00 GMT Follow provider data into StockMetrics, learn what missing-value diagnostics preserve, and see which gaps can still mislead a model. python valuation data-quality https://albertoduran.com/thejournal/mlscraper/first_price_watch/ https://albertoduran.com/thejournal/mlscraper/first_price_watch/ Sat, 20 Jun 2026 00:00:00 GMT Follow one illustrative Amazon Mexico watch from YAML and URL preview to saved product history, runtime health, and a later price alert. python scraping tutorial automation https://albertoduran.com/thejournal/mlscraper/ https://albertoduran.com/thejournal/mlscraper/ Thu, 18 Jun 2026 00:00:00 GMT One missed bargain became MLScraper, a Python service that watches four stores, preserves price history, and treats unreliable pages with care. project python scraping fastapi https://albertoduran.com/thejournal/mlscraper/fetching_and_backoff/ https://albertoduran.com/thejournal/mlscraper/fetching_and_backoff/ Thu, 18 Jun 2026 00:00:00 GMT Learn how MLScraper chooses HTTP or browser fetching, protects history after incomplete pages, and slows the right scope after failures. python playwright scraping operations https://albertoduran.com/thejournal/mlscraper/job_configuration/ https://albertoduran.com/thejournal/mlscraper/job_configuration/ Thu, 18 Jun 2026 00:00:00 GMT Learn how MLScraper turns stable job identity and provider options into validated store routes, predictable storage paths, and safe previews. python configuration scraping https://albertoduran.com/thejournal/mlscraper/operations_and_extension/ https://albertoduran.com/thejournal/mlscraper/operations_and_extension/ Thu, 18 Jun 2026 00:00:00 GMT Run MLScraper locally, diagnose health and saved state, exercise its offline tests, and extend the provider contract without runtime leaks. python testing operations scraping https://albertoduran.com/thejournal/mlscraper/persistence_and_lifecycle/ https://albertoduran.com/thejournal/mlscraper/persistence_and_lifecycle/ Thu, 18 Jun 2026 00:00:00 GMT Follow one stable product identifier through updates, temporary absence, recovery, JSON persistence, and MLScraper price-drop alerts. python data persistence state-machines https://albertoduran.com/thejournal/mlscraper/provider_boundaries/ https://albertoduran.com/thejournal/mlscraper/provider_boundaries/ Thu, 18 Jun 2026 00:00:00 GMT Compare four ecommerce page formats and learn how MLScraper isolates store-specific URLs and parsing behind one product contract. python architecture scraping adapters https://albertoduran.com/thejournal/mlscraper/runtime_flow/ https://albertoduran.com/thejournal/mlscraper/runtime_flow/ Thu, 18 Jun 2026 00:00:00 GMT See how FastAPI starts MLScraper, provider loops share concurrency safely, and health turns background work into observable state. python fastapi asyncio architecture https://albertoduran.com/thejournal/siliconboutique/ https://albertoduran.com/thejournal/siliconboutique/ Thu, 14 May 2026 00:00:00 GMT A benchmarking pipeline that runs Online Boutique locally, on GCP, and on AWS, keeps cloud history in BigQuery, and reports in Grafana and HTML. benchmarking kubernetes gcp terraform observability https://albertoduran.com/thejournal/ai_ops_agent/ https://albertoduran.com/thejournal/ai_ops_agent/ Wed, 13 May 2026 00:00:00 GMT A spec-driven blueprint for an infrastructure AI agent built with LangGraph, Prometheus, and Claude Sonnet, starting from seven markdown files. ai-agents site-reliability langgraph spec-driven-development kubernetes https://albertoduran.com/thejournal/gcp_setup_guide/ https://albertoduran.com/thejournal/gcp_setup_guide/ Sun, 10 May 2026 00:00:00 GMT Set up a Google Cloud account, configure GitHub Actions OIDC auth, and run your first automated benchmark with SiliconBoutique. gcp github-actions terraform iam kubernetes https://albertoduran.com/thejournal/sin_pluma/frontend/ https://albertoduran.com/thejournal/sin_pluma/frontend/ Mon, 02 Mar 2026 00:00:00 GMT How Sin Pluma's React SPA is built: Redux state, HOC auth guards, Axios interceptors, a Slate.js rich text editor, and backend integration. react redux slate-js frontend https://albertoduran.com/thejournal/sin_pluma/ https://albertoduran.com/thejournal/sin_pluma/ Sun, 01 Mar 2026 00:00:00 GMT An academic writing platform introduced me to software architecture and placed second among more than 40 projects after I built it on my own. project software-design docker python react sql https://albertoduran.com/thejournal/sin_pluma/architecture/ https://albertoduran.com/thejournal/sin_pluma/architecture/ Sun, 01 Mar 2026 00:00:00 GMT Every service in Sin Pluma, how Docker networks isolate them, the data flows behind key operations, and the design's strengths and limits. architecture docker microservices docker python react sql https://albertoduran.com/thejournal/sin_pluma/flask_service/ https://albertoduran.com/thejournal/sin_pluma/flask_service/ Sun, 01 Mar 2026 00:00:00 GMT How Sin Pluma's Flask API is built: app factory, blueprints, the full endpoint list, Marshmallow validation, and MySQL, Redis, and MinIO. python flask rest api https://albertoduran.com/thejournal/sin_pluma/innodb_cluster/ https://albertoduran.com/thejournal/sin_pluma/innodb_cluster/ Sun, 01 Mar 2026 00:00:00 GMT How Sin Pluma runs a three-node MySQL InnoDB Cluster: bootstrap, automatic failover, schema management, and hardening beyond the demo. databases MySQL InnoDB cluster https://albertoduran.com/thejournal/sin_pluma/jwt/ https://albertoduran.com/thejournal/sin_pluma/jwt/ Sun, 01 Mar 2026 00:00:00 GMT Sin Pluma's JWT implementation end to end: token structure, lifecycle, the Redis blacklist, the Axios refresh queue, and storage trade-offs. JWT authentication security