A blog for sharing software infrastructure, algorithms, AI, Machine Learning and fun technology.https://tcw165.github.io/blog/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-6-deterministic-workflow/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-6-deterministic-workflow/An agent skill gets a generalist model most of the way. A long workflow is a DAG, so the skill writes a persisted plan and the current step.Fri, 16 Oct 2026 00:00:00 GMTAIhttps://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-5-close-loop/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-5-close-loop/One eval platform: an onion of checks, harness health at the core, and a weekly agent that turns a miss into a fixture PR.Wed, 14 Oct 2026 00:00:00 GMTAIhttps://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-4-eval-sandbox/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-4-eval-sandbox/Local eval without waiting for morning: mock the tools the agent actually sees, synthesize from persona and scenario fixtures, keep production patterns out of git.Tue, 22 Sep 2026 00:00:00 GMTAIhttps://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-3-daily-eval/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-3-daily-eval/The morning job that tells me which commit helped or hurt: in-repo YAML cases, composable scorers, frozen time, and a CLI.Mon, 21 Sep 2026 00:00:00 GMTAIhttps://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-2-agent-loop/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-2-agent-loop/How the in-house agent loop packs a turn: a short sys-prompt, skills in code, a workflow plan as a latch, and history that is not a tool dump.Sun, 20 Sep 2026 00:00:00 GMTAIhttps://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-1-overview/https://tcw165.github.io/blog/posts/building-an-ai-product-in-finance-1-overview/A map of an AI assistant at a consumer brokerage, and why the client uses turn-based SSE plus short poll.Sat, 19 Sep 2026 00:00:00 GMTAIhttps://tcw165.github.io/blog/posts/cpp-competitive-arithmetic-tricks/https://tcw165.github.io/blog/posts/cpp-competitive-arithmetic-tricks/There’re some tricks to make your program run much faster. Although in most cases, the performance boost isn’t noticeable for regular…Sun, 11 Dec 2022 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/n-threads-modify-non-atomic-shared-variable/https://tcw165.github.io/blog/posts/n-threads-modify-non-atomic-shared-variable/I recently am asked with this pseduo code for concurrent programming problem:Wed, 30 Nov 2022 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/reason-about-weighted-matrices-in-neural-network/https://tcw165.github.io/blog/posts/reason-about-weighted-matrices-in-neural-network/Weights matrix is a linear transformation that either squash space or expands spaceSun, 11 Oct 2020 00:00:00 GMTMachine Learninghttps://tcw165.github.io/blog/posts/heaps-algorithm-fun-observation/https://tcw165.github.io/blog/posts/heaps-algorithm-fun-observation/Heap’s Algorithm is NOT heap sort, and instead, it’s an algorithm to generate permutations.Mon, 19 Aug 2019 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/rxjava-handling-errors-like-a-pro/https://tcw165.github.io/blog/posts/rxjava-handling-errors-like-a-pro/Why the error is the terminate event in RxJava? How to bring the reactive streams back to alive after it is terminated by an error?Sun, 21 Apr 2019 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/rxjava-flatmap-switchmap-terminate-events/https://tcw165.github.io/blog/posts/rxjava-flatmap-switchmap-terminate-events/How does a flatMap or switchMap handle a terminate event such as Observable.empty() or Completable.complete()Tue, 04 Dec 2018 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/kotlin-dive-into-inline-byte-code-level/https://tcw165.github.io/blog/posts/kotlin-dive-into-inline-byte-code-level/From the official document, we know the inline function is similar to C/C++ Macro, where the instruction of the function is…Sun, 04 Nov 2018 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/recyclerview-add-line-divider-in-xml/https://tcw165.github.io/blog/posts/recyclerview-add-line-divider-in-xml/The RecyclerView supports addItemDecoration method since 22.1.0 and many people use this method to add line divider, but programmatically…Thu, 11 Oct 2018 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/rxjava2-takewhenobservable/https://tcw165.github.io/blog/posts/rxjava2-takewhenobservable/Updated: Jun 28, 2018Fri, 22 Jun 2018 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/rxjava2-reactive-destruction-with-custom-observable-single/https://tcw165.github.io/blog/posts/rxjava2-reactive-destruction-with-custom-observable-single/The blog post refers to RxJava 2.1.13Mon, 30 Apr 2018 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/largest-rectangular-area-in-histogram/https://tcw165.github.io/blog/posts/largest-rectangular-area-in-histogram/I found an interesting problem on LeetCode and GeeksForGeeks a while ago, “largest rectangular area in the histogram,” and a friend…Sun, 14 Jan 2018 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/rxjava-handle-cancellation-with-switchmap/https://tcw165.github.io/blog/posts/rxjava-handle-cancellation-with-switchmap/2018/03.29 Updated: RxAndroid -> RxJava in title. 2018/02/19 Updated: Add “try #3” with takeUntil.Tue, 26 Dec 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/something-about-android-windowistranslucent/https://tcw165.github.io/blog/posts/something-about-android-windowistranslucent/You could make an Activity float on the other Activities with a translucent window background, e.g. PicCollage app. That provides the end…Mon, 18 Dec 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/group-update-with-long-press-and-single-tap/https://tcw165.github.io/blog/posts/group-update-with-long-press-and-single-tap/I’m always fascinated with building photos editor on the phone, and it’s always hard to do complicated photos/layers manipulation within…Fri, 06 Oct 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/show-the-splash-screen-image-without-any-delay/https://tcw165.github.io/blog/posts/show-the-splash-screen-image-without-any-delay/Many Android apps have splash screen. I used to create the splash screen as follow:Tue, 01 Aug 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/face-landmarks-detection-part-3/https://tcw165.github.io/blog/posts/face-landmarks-detection-part-3/Related articles: Part 1, Part 2Sun, 14 May 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/cross-compile-google-protobuf-lite-for-android-jni/https://tcw165.github.io/blog/posts/cross-compile-google-protobuf-lite-for-android-jni/If you have ever been integrating c/c++ library to your Android project, you probably will know how painful it is to pass complicated data…Wed, 26 Apr 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/face-landmarks-detection-part-2/https://tcw165.github.io/blog/posts/face-landmarks-detection-part-2/Related articles: Part 1, Part 3Sun, 16 Apr 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/face-landmarks-detection-part-1/https://tcw165.github.io/blog/posts/face-landmarks-detection-part-1/Related articles: Part 2, Part 3Sat, 15 Apr 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/build-a-cursorrecyclerviewadapter/https://tcw165.github.io/blog/posts/build-a-cursorrecyclerviewadapter/There is no equivalence of CursorAdapter to the RecyclerViewAdapter family. However, I need a cursor version of the RecyclerViewAdapter to…Sun, 09 Apr 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/fix-ghost-image-by-glide-in-the-recyclerview/https://tcw165.github.io/blog/posts/fix-ghost-image-by-glide-in-the-recyclerview/I use Glide library to load image in the RecyclerView and happen to meet this “ghost image” problem like following.Fri, 31 Mar 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/build-fun-ui-with-coordinatorlayout/https://tcw165.github.io/blog/posts/build-fun-ui-with-coordinatorlayout/This is a blog post about exploring the idea behind the CoordinatorLayout and why it is created. So you won’t see the basic usage of the…Wed, 22 Mar 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/handling-iap-elegantly-in-android/https://tcw165.github.io/blog/posts/handling-iap-elegantly-in-android/Let’s assume that your app has many entries (Activity/Fragment/Service) to access the IAP(In-App-Purchase) and you might also handle the…Thu, 05 Jan 2017 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/jni-and-protobuf/https://tcw165.github.io/blog/posts/jni-and-protobuf/AndroidSat, 15 Oct 2016 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/birthday-permutations/https://tcw165.github.io/blog/posts/birthday-permutations/ProbabilitySat, 06 Aug 2016 00:00:00 GMTProbabilityhttps://tcw165.github.io/blog/posts/tips-of-numpy/https://tcw165.github.io/blog/posts/tips-of-numpy/Machine LearningSat, 09 Jul 2016 00:00:00 GMTMachine Learninghttps://tcw165.github.io/blog/posts/longest-increasing-path-in-a-matrix/https://tcw165.github.io/blog/posts/longest-increasing-path-in-a-matrix/AlgorithmsSun, 05 Jun 2016 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/verify-preorder-serialization-of-a-binary-tree/https://tcw165.github.io/blog/posts/verify-preorder-serialization-of-a-binary-tree/AlgorithmsSun, 05 Jun 2016 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/maximal-rectangle/https://tcw165.github.io/blog/posts/maximal-rectangle/AlgorithmsSun, 05 Jun 2016 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/trapping-rain-water/https://tcw165.github.io/blog/posts/trapping-rain-water/AlgorithmsSat, 04 Jun 2016 00:00:00 GMTAlgorithmshttps://tcw165.github.io/blog/posts/microsoft-build-2016-part-1/https://tcw165.github.io/blog/posts/microsoft-build-2016-part-1/Before we go further (Build 2016), you probably would be interested of taking the keynotes below first in order to come out your ideas…Wed, 06 Apr 2016 00:00:00 GMTTechnologyhttps://tcw165.github.io/blog/posts/rx-android-day-1/https://tcw165.github.io/blog/posts/rx-android-day-1/AndroidWed, 30 Mar 2016 00:00:00 GMTAndroidhttps://tcw165.github.io/blog/posts/set-pre-post-android-matrix/https://tcw165.github.io/blog/posts/set-pre-post-android-matrix/AndroidFri, 19 Feb 2016 00:00:00 GMTAndroid