Seattle Systems · Sept 30

The full recordings and clips from the September 30 meetup at SURF Incubator: the opening, Marc Brooker on temporal policy for AI agents (Dogwood), and Khawaja Shams & Daniela Miao on evals for coding agents.

The Trailer 70s

sizzle download

What Seattle Systems is about · 70 seconds

Deep engineering talks, right here in Seattle: run by engineers for engineers, company-neutral, no sales decks, monthly and free. Marc, Khawaja, and Daniela show what the talks are like, and Sitesh does, like, 85% of the work. Find the next one at seattlesystems.xyz. Music: “Voxel Revolution” by Kevin MacLeod, CC BY 4.0.

Why Seattle Systems

Seattle Systems is a meetup for people who build the hard parts: databases, distributed systems, and lately the agents that sit on top of them. The format is simple. Two deep technical talks, a room that fills up, and food you did not have to pay for.

This night was exactly what these nights are. Marc Brooker walked through a new language for governing what agents are allowed to do, with real math and real database tradeoffs. Khawaja Shams and Daniela Miao showed what it takes to evaluate coding agents, stumbles first, because speakers here bring their stumbles rather than their launch decks. The questions from the room were the kind you only hear from people who have been paged for the same problems. The conversations outlasted the recordings.

“Sitesh does, like, 85% of the work.”

From the opening remarks, and accurate. Seattle Systems wouldn’t be Seattle Systems without him.

If you build systems in Seattle, come to the next one. There will be food, courtesy of the Antithesis folks. Do not trust them.

Full Videos 3

full video download srt vtt

The Opening

Sitesh’s welcome, the Seattle Systems story, sponsor & speaker intros.

full video download srt vtt

Marc Brooker — Temporal Policy for AI Agents

00:20 Dogwood & temporal policy · 02:36 Why deterministic policy · 06:05 Policy examples · 12:27 Why not Python/Rust/TS · 17:19 Open source runtime · 19:37 Compiling to SQL · 21:56 Concurrency control · 28:12 Temporal logic foundations · 33:47 Q&A

full video download srt vtt

Khawaja & Daniela — Evals Is the New Black (Box)

00:00 Opening & systems framing · 02:08 What an eval is · 06:15 Reasoning-effort surprises · 12:29 Your repo has culture · 19:05 Agents find the answer key · 28:29 pass@k: capability vs reliability · 42:43 Harness lessons · 45:30 Testing the whole setup · 53:50 Q&A

Marc Brooker — Clips 12

brooker open srt

Deterministic Policy Not LLM Judges

Sets Dogwood apart from LLM-as-judge/heuristic guardrails and explains why systems engineers should care.

brooker open srt

The Core Agent Control Tension

The whole agent-governance problem in one clean, high-share clip: useful autonomy versus hard boundaries.

brooker open srt

Dont Email After Reading Confidential Data

Concrete security example that stands alone: reading confidential data and sending email are safe separately, risky in sequence.

brooker open srt

Only Commit After Tests Pass

Highly relatable dev-agent policy: no commit unless the immediately preceding relevant action was a successful test.

brooker open srt

Policy Bugs Are Still Bugs In Python

A crisp argument for DSLs: the subtlety exists either way, but Dogwood makes it more visible and analyzable.

brooker open srt

Formal Proof Of A Spending Limit

Punchy formal-methods payoff: prove a million-line policy will never spend over $1,000.

brooker open srt

Dogwood Compiles To SQL

Great database/systems hook: temporal policy maps to SQL, and strong consistency becomes a policy requirement.

brooker open srt

Concurrency Control Or Sell Twice

Turns database isolation into a vivid policy correctness problem: one approval, two concurrent sales.

brooker open srt

Temporal Logic Is The Foundation

Nice explainer segment: temporal operators make before/after/since policies mathematically grounded.

brooker open srt

Negative Tests For Agent Policy

Useful testing/process clip: write failing cases and maybe generate them with property-guided fuzzers.

brooker open srt

Allow List Agents Dont Deny List The World

Strong Q&A answer for broad-capability agents: deny listing fails, allow listing is the safer mental model.

brooker open srt

Dogwood Is Not The Sandbox

Clear boundary-setting clip: policy needs isolation and interception; Dogwood is part of the box, not the whole box.

Evals Talk — Clips 12

sizzle download

The talk in 80 seconds

Khawaja and Daniela trade the best lines: token costs, repo culture, agents that cheat creatively and optimize the checklist, the all-nighter the harness invalidated, and the takeaway: remain skeptical, disconfirm your beliefs. Music: “Voxel Revolution” by Kevin MacLeod, CC BY 4.0.

evals open srt

Evals Need CI Too

Makes the case for continuous coding-agent evals because models, harnesses, and repos keep changing.

evals open srt

High Reasoning Can Hurt

Strong counterintuitive hook: more reasoning is not just slower and pricier, it can be less accurate.

evals open srt

Your Repo Has Culture

Great framing for enterprise evals: PRs, rejections, tests, and history encode what generic benchmarks miss.

evals open srt

Prompts Too Clean To Be Real

Names a hidden eval failure mode: benchmark prompts can become unrealistically helpful and unrepresentative.

evals open srt

Agents Find The Answer Key

Funny, concrete war story: agents inspect Git history, local checkouts, and neighboring processes unless the harness blocks them.

evals open srt

Agents Optimize The Checklist

Explains eval-awareness without anthropomorphizing: agents optimize visible grading criteria like humans optimize checklists.

evals open srt

Pass At K Is Capability

Clear systems-friendly explanation of pass@k and why cheap models can still be useful if success is detectable.

evals open srt

Reliability Is Pass Every Time

Memorable contrast between capability and reliability, with a punchy high-stakes example.

evals open srt

Attribute The Variance

Turns noisy eval runs into an engineering practice: inspect traces, explain variance, build mechanical empathy.

evals open srt

Truncate Tool Context

Deeply practical harness lesson: tool output truncation can cut context bloat without losing recoverability.

evals open srt

Testing The Whole Setup

The thesis of the talk in one clean arc: evals are not model benchmarks, they are system measurements.

evals open srt

Stay Skeptical Disconfirm Beliefs

Good Q&A clip for practitioners: let agents compete, but keep re-testing because today's best setup can decay tomorrow.