Fadel Lukman Hakim is a software engineer who builds products end to end: backend systems in Go and Python, web frontends, and LLM-powered features.https://fadellh.pages.dev/https://fadellh.pages.dev/posts/rebuilding-an-oms-in-eight-weeks/https://fadellh.pages.dev/posts/rebuilding-an-oms-in-eight-weeks/The vendor shut down, inventory stopped syncing to three marketplaces, and overselling became the number one business risk. Here is how we rebuilt the OMS from scratch in Go.Tue, 20 Oct 2026 00:00:00 GMThttps://fadellh.pages.dev/posts/cutting-an-llm-prompt-from-100k-to-16k-tokens/https://fadellh.pages.dev/posts/cutting-an-llm-prompt-from-100k-to-16k-tokens/A price-estimation agent for car workshops had to run on GPT-4o-mini and still be accurate. The first prompt was 100K tokens. Here is how it got to 16K and got better.Mon, 28 Sep 2026 00:00:00 GMThttps://fadellh.pages.dev/posts/silent-oauth2-reauthentication/https://fadellh.pages.dev/posts/silent-oauth2-reauthentication/X tokens expire in two hours. Workflows ran for longer than that and failed with a 401 nobody could explain. The fix became the platform standard for every OAuth2 integration.Sun, 30 Aug 2026 00:00:00 GMT