Thinksy EngineeringEngineer usage detail
FY2027 · Feb 2026 – Jan 2027Data through Oct 2026
← Engineering Effectiveness report
Social Publishing · Jamie Park

Indigo

Engineer · AI usage, harness practices and where spend could have gone further.

Demonstration report. This engineer and their usage are synthetic.

This page is for the engineer and their manager to find cheaper defaults and harness fixes. It is never used to rank people.

Period
01

Summary

FY2027 to date

AI spend
$1,798
187 sessions · $10 each
Savings opportunity
$456
25% of spend, at list price
Practices on target
2 of 7
Focus: Knowledge MCP use, rtk coverage
Cache hit rate
82%
Team 82% · org 82%
02

Where spend could go further

FY2027 to date · estimated at list price

Savings opportunity by lever

$456 of $1,798 spend

Improve prompt caching$259Right-size models$120Keep context lean$57Route commands through rtk$20

What to change

Largest saving first

  1. Improve prompt caching$259

    Cache hit rate 82% against an 85% target.

    Keep stable context at the front of prompts and avoid switching models mid-session, so 85% of input reads from cache.

  2. Right-size models$120

    46% of routine spend ran on Opus: code research $163 of $342, documentation $60 of $147, ops $47 of $99, presentation $24 of $57.

    Run docs, decks, ops and read-only research on Sonnet instead of Opus.

  3. Keep context lean$57

    10% of input tokens were past 100K of context.

    Compact or /clear between tasks instead of carrying more than 100K tokens of context.

  4. Route commands through rtk$20

    61% of 1,716 Bash calls ran through rtk; 2.8M tokens of command output went into context.

    rtk compacts test, build, git and search output before it reaches the model (about 70% smaller).

03

Harness practices

Compared with Social Publishing and the organization

PracticeIndigoTeamOrgTargetRecommendation
rtk coverage61%Needs attention63%56%≥ 80% of Bash callsInstall the rtk hook so test, build, git and search commands return compact output.
Knowledge MCP use3%Off target4%30%≥ 40% of sessionsSearch the knowledge MCP before re-researching a codebase, and save findings back with remember.
Cache hit rate82%Needs attention82%82%≥ 85% of inputKeep CLAUDE.md and tool lists stable, avoid mid-session model switches, and resume sessions instead of restarting.
Context past 100K10%On target9%10%≤ 10% of inputOn target
Opus on routine work46%Needs attention44%44%≤ 25% of routine spendDefault routine sessions to Sonnet and keep Opus for harness, design and hard debugging work.
Sessions using subagents47%On target46%50%≥ 30% of sessionsOn target
Tool error rate4.1%Needs attention3.7%3.0%≤ 4% of tool callsFix recurring failures (permissions, env vars, flaky tests) in the harness rather than letting the agent retry.

Practices by month

Is the engineer moving toward the targets?

MonthrtkKnowledgeCacheContextModel fitSubagentsSavings opportunity
Feb 2026––62%Off target7%On target62%Off target38%On target$65
Mar 2026––65%Off target7%On target62%Off target25%Needs attention$46
Apr 2026––67%Off target6%On target62%Off target30%On target$58
May 202618%Off target–72%Needs attention9%On target55%Off target32%On target$87
Jun 202643%Needs attention0%Off target76%Needs attention7%On target53%Off target37%On target$46
Jul 202665%Needs attention5%Off target80%Needs attention8%On target40%Needs attention45%On target$36
Aug 202669%Needs attention4%Off target79%Needs attention10%Needs attention38%Needs attention49%On target$69
Sep 202671%Needs attention3%Off target87%On target11%Needs attention30%Needs attention58%On target$29
Oct 202665%Needs attention2%Off target90%On target11%Needs attention27%Needs attention53%On target$19
04

Usage

FY2027 to date

AI spend by model

By model tier, by month

  • Opus
  • Sonnet
  • Haiku
  • Other
$0$100$200$300$400$134Feb$96Mar$144Apr$200May$169Jun$172Jul$322Aug$288Sep$274Oct

AI spend by session type

Routine types (documentation, presentation, ops, code research) rarely need Opus

Harness$317Freeform$626Code research$342Documentation$147Ideation$210Ops$99Presentation$57

Tokens by model

Cache reads are billed at a fraction of uncached input; a high share is what good caching looks like

ModelRequestsUncached inputCache readsCache writesOutputSpend
Opus 5.52,5798.1M142.7M9.6M3.3M$174
Opus 52,88419.8M139.3M10.2M4.1M$335
Opus 4.81,72415.1M72.6M5.6M2.1M$200
Opus 4.62,47238.9M101.2M8.9M3.8M$397
Opus 4.51683.3M6.4M619K266K$30
Sonnet 5.53,1438.7M161M10.8M4.6M$106
Sonnet 53,95926.2M199.6M14.4M6.1M$285
Sonnet 4.61,85225M78.7M6.6M2.7M$164
Sonnet 4.51613.2M6.2M602K279K$18
Haiku 5.53,4719.2M183.9M12.3M5.4M$7
Haiku 4.52,75124.5M128.5M9.8M4.1M$70
GPT Realtime (meetings)1571.1M7.2M528K206K$13
Total25,321183.1M1227.3M90M36.9M$1,798

Methodology

  • Spend and tokens come from LiteLLM gateway logs and imported agent session history, priced at API list rates.
  • Savings are estimates: routine Opus work repriced at the Sonnet available at the time; uncached input moved to cache reads up to an 85% hit rate; rtk removing 70% of unfiltered command output, which stays in context for about half the session's remaining turns; and 50% of input past 100K context avoided by compacting. Levers overlap, so the total is an upper bound.
  • rtk and the knowledge MCP are scored from their rollout (rtk May 2026, knowledge MCP Jun 2026).
  • Generated Oct 20, 2026, 7:46 AM.
Engineer Usage Detail (demo) · Thomas Tucker