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

Avery

Lead 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
$2,277
191 sessions · $12 each
Savings opportunity
$549
24% of spend, at list price
Practices on target
3 of 7
Focus: rtk coverage, Knowledge MCP use
Cache hit rate
84%
Team 82% · org 82%
02

Where spend could go further

FY2027 to date · estimated at list price

Savings opportunity by lever

$549 of $2,277 spend

Improve prompt caching$352Right-size models$105Keep context lean$73Route commands through rtk$19

What to change

Largest saving first

  1. Improve prompt caching$352

    Cache hit rate 84% 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$105

    41% of routine spend ran on Opus: code research $120 of $313, documentation $109 of $245, ops $18 of $46, presentation $3 of $12.

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

  3. Keep context lean$73

    9% 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$19

    65% of 1,943 Bash calls ran through rtk; 3.1M 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 Content Pipeline and the organization

PracticeAveryTeamOrgTargetRecommendation
rtk coverage65%Needs attention62%56%≥ 80% of Bash callsInstall the rtk hook so test, build, git and search commands return compact output.
Knowledge MCP use
4 findings saved back
31%Needs attention30%30%≥ 40% of sessionsSearch the knowledge MCP before re-researching a codebase, and save findings back with remember.
Cache hit rate84%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 100K9%On target9%10%≤ 10% of inputOn target
Opus on routine work41%Needs attention57%44%≤ 25% of routine spendDefault routine sessions to Sonnet and keep Opus for harness, design and hard debugging work.
Sessions using subagents57%On target55%50%≥ 30% of sessionsOn target
Tool error rate2.4%On target2.4%3.0%≤ 4% of tool callsOn target

Practices by month

Is the engineer moving toward the targets?

MonthrtkKnowledgeCacheContextModel fitSubagentsSavings opportunity
Feb 2026––58%Off target6%On target62%Off target43%On target$35
Mar 2026––65%Off target11%Needs attention62%Off target36%On target$122
Apr 2026––64%Off target10%On target–55%On target$41
May 202628%Off target–69%Off target7%On target55%Off target42%On target$97
Jun 202651%Needs attention14%Off target74%Needs attention10%Needs attention53%Off target38%On target$71
Jul 202668%Needs attention25%Needs attention77%Needs attention9%On target40%Needs attention49%On target$57
Aug 202669%Needs attention32%Needs attention78%Needs attention10%On target38%Needs attention51%On target$43
Sep 202675%Needs attention39%Needs attention83%Needs attention11%Needs attention30%Needs attention68%On target$51
Oct 202674%Needs attention34%Needs attention92%On target8%On target27%Needs attention76%On target$33
04

Usage

FY2027 to date

AI spend by model

By model tier, by month

  • Opus
  • Sonnet
  • Haiku
  • Other
$0$200$400$600$75Feb$297Mar$113Apr$213May$222Jun$240Jul$180Aug$474Sep$463Oct

AI spend by session type

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

Harness$849Freeform$644Code research$313Documentation$245Ideation$167Ops$46Presentation$12

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 5.54,2029.5M233.8M15.5M6.1M$285
Opus 53,12721.1M144.2M10.6M4.6M$359
Opus 4.81,95021.1M86.4M6.9M3.1M$269
Opus 4.63,21756.3M131.5M12M4.8M$543
Opus 4.5972.2M3.5M360K146K$18
Sonnet 5.56,2339.3M304.6M20M8.6M$186
Sonnet 54,21131.3M219.3M16M6.7M$320
Sonnet 4.62,17230.3M86M7.4M3.2M$192
Sonnet 4.5681.6M2.6M269K116K$8
Haiku 5.59,40312.9M561.7M36.7M13.3M$18
Haiku 4.53,00822.5M133.4M9.9M4.1M$69
GPT Realtime (meetings)991.1M4.6M363K157K$10
Total37,787219.1M1911.5M136M55M$2,277

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