https://eryawan.com/blog/ 17 long-form posts: machine learning surveys, retrieval, reinforcement learning, speech, software practice, and startup economics in Indonesia. en Sat, 31 Oct 2026 00:00:00 GMT https://eryawan.com/blog/software-will-eat-services/ https://eryawan.com/blog/software-will-eat-services/ Sat, 31 Oct 2026 00:00:00 GMT Why the next software companies will buy the service firms they automate: the value equation, where the moat lives, and what breaks it. economics private-equity indonesia startup notes Eryawan Presma Yulianrifat https://eryawan.com/blog/encoder-training-operationalization/ https://eryawan.com/blog/encoder-training-operationalization/ Sat, 30 May 2026 00:00:00 GMT Decide if a retrieval encoder is worth training over BM25 or an API model on nDCG@10, latency and index size, then train one. machine-learning deep-learning information-retrieval notes Eryawan Presma Yulianrifat https://eryawan.com/blog/recommender-systems-arc/ https://eryawan.com/blog/recommender-systems-arc/ Sat, 30 May 2026 00:00:00 GMT Recommender systems from Amazon's item neighbors and the Netflix Prize to two-tower retrieval and generative semantic IDs. machine-learning deep-learning recommender-systems notes Eryawan Presma Yulianrifat https://eryawan.com/blog/software-testing-survival-guide/ https://eryawan.com/blog/software-testing-survival-guide/ Sat, 30 May 2026 00:00:00 GMT Software testing one kind per section, unit to chaos to LLM evals: a tiny example, the bug it catches, and the tool to use. software-engineering testing notes Eryawan Presma Yulianrifat https://eryawan.com/blog/encoders-squash-reality/ https://eryawan.com/blog/encoders-squash-reality/ Wed, 27 May 2026 00:00:00 GMT How encoders squash images and text into vectors, from SIFT and word2vec through BERT and ViT to CLIP's shared space. machine-learning deep-learning notes Eryawan Presma Yulianrifat https://eryawan.com/blog/innovation-indonesia/ https://eryawan.com/blog/innovation-indonesia/ Wed, 27 May 2026 00:00:00 GMT Why Indonesia's innovation flywheel will not spin: rent-seeking grants, a trust deficit, no exit path, and where to push. economics innovation indonesia startup notes Eryawan Presma Yulianrifat Bryan Jeshua https://eryawan.com/blog/agentic-harness/ https://eryawan.com/blog/agentic-harness/ Tue, 19 May 2026 00:00:00 GMT Agentic AI from STRIPS and BDI to ReAct, Toolformer, GRPO and MCP, with open problems and seven portfolio projects. machine-learning deep-learning notes Eryawan Presma Yulianrifat https://eryawan.com/blog/model2vec-explained/ https://eryawan.com/blog/model2vec-explained/ Tue, 19 May 2026 00:00:00 GMT Compress a sentence transformer into a CPU lookup table: vocab prep, PCA, SIF weighting, quantization, and a ~50-line reference. machine-learning deep-learning notes Eryawan Presma Yulianrifat https://eryawan.com/blog/representation-analysis-reading-path/ https://eryawan.com/blog/representation-analysis-reading-path/ Tue, 19 May 2026 00:00:00 GMT Representation analysis in eight papers, from Mikolov's 2013 analogies to sparse autoencoders: concepts as directions. machine-learning deep-learning notes Eryawan Presma Yulianrifat https://eryawan.com/blog/world-models/ https://eryawan.com/blog/world-models/ Tue, 19 May 2026 00:00:00 GMT World models from Sutton's 1990 Dyna through Dreamer, Genie and video simulators to LeCun's JEPA, with open problems. machine-learning deep-learning notes Eryawan Presma Yulianrifat https://eryawan.com/blog/speech-processing/ https://eryawan.com/blog/speech-processing/ Sat, 11 Oct 2025 00:00:00 GMT Spoken language processing notes: ASR, text-to-speech, dialog systems, phonetics, and signal sampling, Nyquist and aliasing. philosophy machine-learning math Eryawan Presma Yulianrifat Dr. Kurniawati Azizah, S.T., M.Phil. (Lecturer) https://eryawan.com/blog/personal-identity-problem/ https://eryawan.com/blog/personal-identity-problem/ Sun, 17 Aug 2025 00:00:00 GMT The personal identity problem in code: the Ship of Theseus, mutable vs immutable objects, Python's id(), and primary keys. philosophy Eryawan Presma Yulianrifat https://eryawan.com/blog/why-python-is-currently-irreplacable/ https://eryawan.com/blog/why-python-is-currently-irreplacable/ Tue, 15 Jul 2025 00:00:00 GMT Why Python's design is hard to replace for data science and AI: C/C++ bindings, duck typing, monkey patching, introspection. python Eryawan Presma Yulianrifat https://eryawan.com/blog/math-problems/ https://eryawan.com/blog/math-problems/ Thu, 10 Apr 2025 00:00:00 GMT Foundational math problems for ML: running mean and variance, linear algebra, maximum likelihood and decision theory. math Eryawan Presma Yulianrifat https://eryawan.com/blog/deep-learning/ https://eryawan.com/blog/deep-learning/ Mon, 24 Mar 2025 00:00:00 GMT Deep learning course notes: probability, likelihood, information theory, regression, classification and backpropagation. machine-learning deep-learning notes Eryawan Presma Yulianrifat https://eryawan.com/blog/rl/ https://eryawan.com/blog/rl/ Mon, 24 Mar 2025 00:00:00 GMT Reinforcement learning course notes: MDPs, Bellman equations, policy iteration, value approximation and policy gradients. machine-learning reinforcement-learning notes Eryawan Presma Yulianrifat Vektor Dewanto, S.T., M.Eng., Ph.D. (Lecturer) https://eryawan.com/blog/general-ml/ https://eryawan.com/blog/general-ml/ Sat, 22 Mar 2025 00:00:00 GMT Machine learning from first principles: Mitchell's definition, three paradigms by analogy, and supervised learning formalized. machine-learning Eryawan Presma Yulianrifat