X Algorithm Optimizer

Optimize content for X's 2026 neural recommendation system. Based on technical analysis of the xai-org/x-algorithm codebase (May 15, 2026 release), this skill provides both tactical templates for immediate use and deep architectural understanding for strategic advantage.

Changelog — 2026-05-15: Re-audited against the xai-org/x-algorithm repo refresh (run_pipeline.py, Grox content-understanding service, ads blending, RankingScorer). See "What Changed (2026-05-15)" at the bottom. Key corrections: the exact action list is now confirmed (no bookmark, no expand_details); negative signals use a bounded normalization, NOT a raw -1000 multiplier; scoring weights are runtime feature-switch params and are NOT published in the repo (do not quote specific numbers as fact).

The Paradigm Shift: Neural > Heuristics

X has moved to an end-to-end neural architecture and, per the repo, has "eliminated every single hand-engineered feature and most heuristics" (README.md). The pipeline:

• Home Mixer: Rust orchestration layer — query hydration → candidate sourcing → hydration → filters → scorers → selector → post-selection filters → ads blending.
• Thunder: In-network candidate source — an in-memory store of recent posts from accounts you follow (sub-millisecond lookups, Kafka-fed).
• Phoenix: Out-of-network retrieval (Two-Tower model over a global corpus) + the neural ranker (a Grok-1-derived transformer).
• Grox: A separate content-understanding service (spam, safety/PTOS, post category, "banger" quality screen, multimodal embeddings).

The implication: posting-time tricks and hashtag stuffing don't work. The Phoenix ranker predicts engagement-action probabilities from your engagement-history embeddings; Grox classifiers screen content quality and safety. Alignment beats manipulation.

Accuracy note: the Phoenix ranker is a Grok-1-derived transformer that operates on hash-based ID embeddings and engagement sequences — it does not "read" your post as natural-language prose. Genuine content reading (spam/safety/category/multimodal) happens in the Grox service.