Software engineer at Upstash, Boğaziçi University graduate. I write about developer tooling, the occasional paper, and Redis - plus a monthly roundup of things I enjoyed reading.https://cahidarda.com/https://cahidarda.com/articles/held-accountable/https://cahidarda.com/articles/held-accountable/AI providers ask us to trust agents with our accounts and real work, while their terms of service put every consequence on the user. Before I hand an agent the keys, one question needs an answer: who is responsible when something goes wrong?Tue, 11 Aug 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/llm-identity-index/https://cahidarda.com/articles/llm-identity-index/We rewrite a model's own answer in the transcript to say the opposite, then ask it to explain itself. Across ten frontier models, 46% of replies defend the planted answer. Opus 4.8 almost never falls for it. Fable 5 does worse than both Opus and Sonnet.Tue, 07 Jul 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/robots-vs-ai/https://cahidarda.com/articles/robots-vs-ai/Factory robots (1990-2015) are the best natural experiment we have for machines replacing workers. The mechanics of displacement carry over to AI, but the target inverts: robots hit the least-educated hardest, while AI exposure rises with skill and income. A data-driven look at who actually loses their job.Sun, 05 Jul 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/the-current-june-2026/https://cahidarda.com/articles/the-current-june-2026/A monthly public record of the links I save - some of what I read this month.Sun, 05 Jul 2026 00:00:00 GMTaccessionshttps://cahidarda.com/articles/data-platform/phase-1-ingest/https://cahidarda.com/articles/data-platform/phase-1-ingest/The end-to-end spine: a synthetic event producer to a Redpanda topic, a Spark Structured Streaming job that upserts current order state into Postgres, and a live orders view served over it.Fri, 26 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/phase-2-observability/https://cahidarda.com/articles/data-platform/phase-2-observability/Making the pipeline legible: Prometheus scraping by pod annotation, a provisioned Grafana dashboard, Loki and Alloy for logs, and consumer lag as a first-class metric. Plus why end-to-end latency has to be instrumented in the app, not inferred.Fri, 26 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/phase-3-columnar/https://cahidarda.com/articles/data-platform/phase-3-columnar/Teeing the same stream into ClickHouse (column/OLAP) and Iceberg-on-MinIO (lakehouse) next to Postgres (row/OLTP), then running the identical analytical query on the row store and the column store to feel the difference on measured numbers.Fri, 26 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/phase-4-resilience/https://cahidarda.com/articles/data-platform/phase-4-resilience/Making the pipeline survive the things a real quarter would throw at it: poison messages routed to a dead-letter topic, backpressure on the consumer, a killed processor resuming from its checkpoint, and an SLO with an error budget you can watch hold. Plus a log-DLQ vs queue-DLQ contrast.Fri, 26 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/https://cahidarda.com/articles/data-platform/A local, end-to-end data platform on one k3d Kubernetes cluster, built on a laptop in tagged phases: streaming ingest, the right storage shape per access pattern, observability, and resilience.Thu, 25 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/architecture/https://cahidarda.com/articles/data-platform/architecture/The data-flow through-line of the local multi-tenant platform: a replayable log feeding a stream processor that tees each record into a row store, a column store, and a lakehouse, plus the cumulative-overlay GitOps model that grows the cluster one phase at a time.Thu, 25 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/phase-0-foundation/https://cahidarda.com/articles/data-platform/phase-0-foundation/The empty cluster and the wiring that makes every later phase a reviewable diff: a k3d cluster, cumulative Kustomize overlays, OpenTofu-generated secrets kept out of git, a Makefile, and the Tilt dev UI.Thu, 25 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/data-platform/storage-shapes/https://cahidarda.com/articles/data-platform/storage-shapes/Why the platform writes the same event into four different stores. The row-versus-column trade-off made physical and quantitative, plus where a replayable log and a lakehouse fit, and how to feel the difference on your own measured numbers.Thu, 25 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/sakana-fugu/https://cahidarda.com/articles/sakana-fugu/Sakana's Fugu orchestrates frontier LLMs into a single endpoint. A guided tour of its two engines (the evolved TRINITY router and the RL-trained Conductor) with interactive diagrams of both architectures.Mon, 22 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/vercel-eve-guide/https://cahidarda.com/articles/vercel-eve-guide/Notes from building a quick demo agent on Vercel Eve: initializing a project, the file layout, the dev TUI, tools and skills, scheduling, channels, deployment, and how it builds on Vercel's stack.Thu, 18 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/rebuilding-this-site/https://cahidarda.com/articles/rebuilding-this-site/A personal site collects everything you do in one place. And you can build one without knowing a thing about the framework it runs on, just focusing on the aesthetics, like Bob Ross.Tue, 02 Jun 2026 00:00:00 GMTbloghttps://cahidarda.com/articles/the-current-may-2026/https://cahidarda.com/articles/the-current-may-2026/A monthly public record of the links I save - some of what I read this month.Sun, 31 May 2026 00:00:00 GMTaccessionshttps://cahidarda.com/articles/poetry-python-not-found-macos/https://cahidarda.com/articles/poetry-python-not-found-macos/Fixing Poetry's missing-python error on macOS without installing python-is-python3.Sat, 27 Apr 2024 00:00:00 GMTbloghttps://cahidarda.com/articles/degreeguru-chatbot/https://cahidarda.com/articles/degreeguru-chatbot/A RAG chatbot template built with the Vercel AI SDK, LangChain, Upstash Vector and OpenAI.Thu, 28 Mar 2024 00:00:00 GMTbloghttps://cahidarda.com/articles/elixir-phoenix-redis/https://cahidarda.com/articles/elixir-phoenix-redis/A tutorial deploying an Elixir/Phoenix app that caches WeatherAPI responses in Upstash Redis on Fly.Thu, 28 Mar 2024 00:00:00 GMTbloghttps://cahidarda.com/articles/static-word-embeddings-turkish/https://cahidarda.com/articles/static-word-embeddings-turkish/A fine-grained intrinsic and extrinsic comparison of contextual and static word embeddings for Turkish.Sat, 09 Dec 2023 00:00:00 GMTpublicationhttps://cahidarda.com/articles/optiver-quant-questions/https://cahidarda.com/articles/optiver-quant-questions/My solutions to the sample quantitative-researcher questions Optiver shares in their job listing.Sun, 17 Sep 2023 00:00:00 GMTbloghttps://cahidarda.com/articles/prisoners-dilemma-rl/https://cahidarda.com/articles/prisoners-dilemma-rl/Replicating win-stay/lose-shift strategy evolution in the iterated Prisoner's Dilemma, with Java multithreading.Sat, 09 Sep 2023 00:00:00 GMTbloghttps://cahidarda.com/articles/tabtransformer-keras/https://cahidarda.com/articles/tabtransformer-keras/Implementing the TabTransformer model in Keras, with an RNN warm-up, during a data-science internship.Tue, 30 Aug 2022 00:00:00 GMTbloghttps://cahidarda.com/articles/artu-goal-models/https://cahidarda.com/articles/artu-goal-models/A tool that generates goal models from agile user stories, letting teams benefit from both representations.Mon, 20 Sep 2021 00:00:00 GMTpublication