H
Howardism
Plate IIEntitiesHOWARDISM

Uber

The ride-hailing and delivery company whose platform team is the corpus's most fully documented in-house AI developer stack. A 2023 Model Gateway, model- and harness-agnostic, carries security middleware, per-user spend tracking and audit traces. AIFX wraps Claude Code, Codex and OpenCode so settings, skills and plugins move between harnesses. On top sit an MCP Gateway (800+ servers), uReview and risk-scored code review, background agents (Minion on 2017's DevPods), and spend tiers that managers can lift. Its engineers report a first-party cost equation, a CI code red after jobs more than doubled in a year, and PRs tagged by work type in place of PR velocity. Every figure is self-reported

Article metadata
Publication details
Published:October 26, 2026
Filed:Entity
Domain:Entities
Reading:9 min
Source:AI-synthesised
About this piece

Articles in this journal are synthesised by AI agents from a curated wiki and are refreshed automatically as new concepts arrive. Topics, framing, and editorial direction are curated by Howardism.

Illustration for Uber

Sources#

What it is#

The ride-hailing and delivery company. It appears in this wiki as an adopter that publishes its own internals. Five sources in the corpus describe its AI developer stack. Three are first-party: two Uber engineering-blog posts and a podcast interview with Distinguished Engineer Uday Kiran Medisetty, who leads much of the company's agentic-AI work and authored or co-authored all three. The other two are Gergely Orosz's relays of Uber charts and diagrams. No other organization in the corpus is documented from the model layer up to the review queue. Every number is Uber's own, and none is audited.

The podcast account (Uber's AI infra from the inside (with Uday Kiran Medisetty), 2026-10-14) explains why the stack is in-house. In 2015 off-the-shelf software could not handle Uber's scale or did not exist. Its examples are M3DB (about 500 million metrics a second), Cadence (durable multi-day workflows, later the basis of Temporal), Morpheus (feature flags combined with experimentation for multi-sided marketplaces) and uOwn (service ownership). Cities are a primitive all the way down: each is pinned to a cloud region and can fail over. The service count went from two in 2015 to thousands by 2019, and Medisetty expects about the same number in 2026 against a business roughly 10× larger.

The AI stack, layer by layer#

LayerWhat it isWhere the wiki treats it
Model Gateway (2023)One gateway for every AI call, built on a platform decision that everything AI-related be model- and harness-agnostic. It routes to Anthropic, OpenAI, other vendors and self-hosted open models. Extensions: AI Guard (a security-team middleware that checks every request and response and flags slow models or queries), per-user spend tracking, audit logs and session tracesStandardize the Infrastructure, Not the Tools
AIFX (AI Foundations)A wrapper over the supported harnesses (Claude Code, Codex, OpenCode). An engineer who switches harness keeps their settings, skills and plugins. Its CLI (aifx) also routes MCP calls through the gateway (Code Mode) and runs afx validateStandardize the Infrastructure, Not the Tools, Tool-Catalog Context Cost
MCP Gateway800+ MCP servers and 5,000+ tools behind one data plane: caller-typed tool-level authorization, metering to Kafka/M3, PII redaction, third-party token exchange, and a registry where generated tools stay disabled until their owner enables them. Built fast because the Thrift and Protobuf registries already existedMCP and Computer Use, Tool-Catalog Context Cost
Context Graph24M nodes and 80M edges across 30+ source systems, used to ground agent queries (Jaeger tracing made it easier to build)Cost-per-Task Over Cost-per-Token
Minion (2025)Background agents, running on DevPods, the remote dev environments Uber built in 2017this page
uReview / Code InboxAI review on every PR: pluggable generators, then grader, dedup and category filters. By the time a human opens a change, AI review has run, screenshots or videos are attached where relevant, and a risk score is assignedDeterministic Engineering for Agent Code Review, Risk-Tiered Auto-Approval
Slate, Wisdom, ShepherdSlate replays production sessions in personal staging instances. Wisdom aggregates logs for similar issues into repro steps and a root-cause analysis with a "Fix with an Agent" action. shepherd-bot authors automated "[self-healing]" code-quality PRs (seen in the Code Inbox screenshot)this page

Medisetty's summary of why the stack arrived quickly: "All the things that we built to make life easier for engineers: it makes it easier for our agents as well!" Orosz frames it as roughly a year of AI tooling built on top of a decade of developer-tooling investment. In this corpus Uber is the strongest case that an AI-ready organization is mostly an already-instrumented one. It is also a case only a company that already had a platform organization of this size can make.

Spend governance#

Three mechanisms, from two first-party sources:

  • Spend tiers with manager override (podcast). Each engineer is allocated a monthly spend tier. Past it, their manager can sign off on more. "For the right type of work, there is no spend limit, but Uber doesn't want engineers to carelessly burn tokens." It is a ceiling with an escape hatch, the mirror image of the usage floor measured on AI Usage Mandates and Quota Gaming.
  • CostCheck (podcast), a plugin that works across sessions and suggests how an engineer can improve their cost profile. Together with the blog's live per-user cost counters, Slack nudges at 50/80/100% of expected spend and a 16-category anti-pattern dashboard (Running a Software Factory Efficiently at Uber Scale), it is visibility handed to the individual rather than reported upward.
  • The cost line. The podcast repeats "reduced token costs by about 50% the last few months" as previously reported. The blog's own figures are cost per 1,000 requests −34% and cost per session −52%, each measured at its trough with one model held fixed. Orosz's chart caption says "per-token costs are down 50%+". These are three different units, so they do not corroborate one another. See Cost-per-Task Over Cost-per-Token and AI Product Economics Maturation.

Throughput, review and CI#

  • Code review is the admitted bottleneck. Every PR is still reviewed by an engineer. The tooling exists so the reviewer can decide how much time a change needs. AI review, attached media and a risk score are all in place before a human looks. The risk score here allocates attention. It is not the auto-approval gate on Risk-Tiered Auto-Approval.
  • CI code red (early 2026). CI jobs more than doubled in 12 months, and Uber declared an internal code red. The response was to move simple jobs (linting, build and template rules) into the agent's inner loop: agents run afx validate before opening a PR. That is volume outrunning a verification control, the system-level strain on Acceleration Whiplash, plus a fix that moves a check earlier rather than adding capacity. See Layered Supervision and the CI-capex question on Verification as the New Bottleneck.
  • PRs tagged by work type, not PR velocity. Uber used to measure how long a diff took to reach production. Agents make PRs cheap and many have no business impact, so every PR is now tagged as feature, bugfix, maintenance, testing or docs. The feature share is rising and the maintenance share falling. Spotify reports the same instrument and the same maintenance direction (Acceleration Whiplash). Neither publishes its classifier.
  • >70% of PRs agent-attributed, with 3,600+ agent skills and 30K+ skill executions a day (blog, August 2026).

The engineer's job, in Medisetty's words#

"The job of engineering is, in some sense: 'how do you build the right context for the agents to produce reliable output?'" He names three skills that now matter more: context engineering, multitasking across parallel work, and reviewing and verifying agent output. See Compute Allocator.

Evidence weight#

case-study throughout. The podcast source is a newsletter author's written summary of an interview. The transcript is not in the vault, so nothing attributed to the podcast here is a verbatim transcript reading except the two quoted passages Orosz prints. Uber publishes no classifier for its PR tagging, no CI-job or cost baselines, and no outcome measures for review risk scoring. Directions are the defensible part.

Connections#

Sources#

§ end
Cited by 9
Related articles
  • Open Questions Backlog

    Generated by `_system/lint.py --write-backlog`. Do not hand-edit. Domain and Watching sections carry one row per page —…

  • Layered Supervision

    Stolze & Strässle (ESEM 2026 SEIP, 5 interviews + a 50-person indicative survey): as generation outruns review, supervi…

  • Pilot-to-Production Gap

    Anthropic × Accenture's account of why enterprise AI pilots don't predict production: the pilot's success conditions —…

  • Review as the Control Point

    Agarwal et al. (CMU, arXiv 2607.07980): a 26-construct/67-relationship causal theory synthesized from 3,100 coded pract…

  • Verification as the New Bottleneck

    Fiona Fung: coding is no longer the bottleneck — verification, review, maintenance are; shift-left; TDD loses its tax;…