// HACKER NEWS — CYBERSECURITY
The Harness Is the Thing
When I started out as a developer, I had a graybeard observe for me that
Moore's law also applies to software. I didn't understand that this constant conversation about how we were solving problems was the arc of progress; that complaining about J2EE and how slow Netbeans was, and wheezing about table-based layouts and constant full-page reloads, was the day-to-day optimizing that is also an engine of progress.
The last eighteen months have been a particular window of relentless
improvement. Tab completions have given way to agentic coding which has given
way to managing your agents with a harness. I've gone from being awed at the
productivity gains to settling into the game and squeezing the lemon to see what
I can get.
Single developer projects can build to the caliber and consistency of large
development teams. You can and should build bespoke applications and you don't
have to sweat onboarding experienced engineers; if they know their stack
backwards and forwards they'll quickly know how to contribute to yours. But most of all, I have learned that the harness is the thing; the fulcrum from which my expectations meet the LLM's capabilities.
At the moment my rig is supported by two subscriptions (Cursor, Claude) that I can augment with Pi as needed. All three share my skills and AGENTS.md. Though I am using three TUIs, I have a unified experience. This has commodified the models for me; there is no magic sauce or special experience in Claude or Cursor that I need in order to be productive. I have zero anxiety about the transition from Cursor to Codex at the end of this month.
In the
commodity1 era I can get great results from a host of available models, but I've been leaning on deepseek-v4-flash-0731 since it came out. It's a rare case that I dip into my Anthropic API budget to utilize Fable.
I can run Deepseek on most maintenance and simple tasks. It's when I am exploring a serious feature or large refactor with lots of moving parts that I reach for the frontier. Recently I learned about prewalk2, Can Bölük's technique that uses frontier for the planning phase and first task, then hands off once the pattern is set. I paired it with the planner/worker/critic split from Building an Advanced Agentic Harness3 - a single prompt that plans, executes, and critiques itself confuses its own objectives, so each role gets isolated instead. I built both into a skill, with a supporting Pi extension that can take over at any stage of work.
Exploration leads to a plan formalized into an explicit DAG (directed acyclic graph) task list. Then a worker takes over, focusing on implementing the DAG one node at a time. Once complete, I bring in the critic to simplify and question what was implemented. Often this phase will push back enough that the worker phase is revisited. But once satisfied, the critic gives way to a promoter, which is my reminder that a job is not complete until you've properly communicated it to others.
I added the promoter step to shore up a weak spot I have for wanting to ship and move on. It's my reminder to let people know about work I'm completing. I need a little help from Fable in this phase, as promotion is subtle and easily borked, and nobody likes a critic so running it through the frontier gives it more weight.
This has dropped my usage of Fable in even my most intense contexts by 75%. This feels sane, something akin to AI soak. I can take care of my clients and make real progress on my own projects on my two twenty-dollar plans, as I juggle in and out of Pi for Deepseek or the Fable infusion.
My product4 is a camera app designed to make it easy to take a picture and see it converted into a vector graphic, one at a time. It's fun because it's simple. The resolution drops, the picture is simplified into value layers, and shapes. It keeps the context and removes the detail so you can draw it back in. That's all it's designed to do. You print it out and you draw on top of it. Or import it into Procreate and