Rod Morehead's Blog
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8- LLMs Coding Now Achieves Roomba Bump and Turn – But Where Can't They Go?

Remember the original “bump and turn” Roomba? Adorable in its clueless way—seldom getting permanently stuck, cleaning small to medium rooms through sheer inefficient, statistical persistence: spiral out until a wall, follow along it, bump an obstacle, back up, turn a random-ish angle, repeat until probability says most of the floor is covered.

That’s exactly where LLM-assisted coding sits in early 2026. As someone who leans heavily on agentic LLMs for real work, I can report a huge functional leap in the last couple of months.

Vendors have bolted on better “bump sensors” (self-critique, reflection prompts, error detection) and “smarter turns” (tree-of-thought branching, sampling variants, longer contexts, agent loops). Supervision drops dramatically—a task that once needed five or six prompt revisions and manual fixes now often resolves in one or two agent iterations. Huge win for engineers who ship code for a living.

LLM vendors love it—they’re in the token-selling business. Hardware vendors love it too—more retries, bigger contexts, endless loops mean more compute demand. It’s a smart adaptation to the hard walls current models still slam into, even as they get “smarter.” The model keeps moving: bump into a coherence issue or corpus reversion, back up, critique, branch, retry. It never truly gets stuck (given enough tokens and patience), and outputs improve in usefulness and coherence.

But never gets stuck ≠ can go anywhere.

Behind those walls? Novelty. LLMs are world-class remixers within their training distribution—petabytes of code, docs, Stack Overflow, GitHub from ~2025 and earlier. Push too far outside that neighborhood (idiosyncratic patterns, paradigm-shifting abstractions, deep domain intersections), and they hit a brick wall. The output turns novice: overconfident hallucinations, subtle drift to corpus defaults, or flailing that demands exponential token burn (reflection chains, multi-step critique loops) to salvage something workable. Recent “advancements” make bumping more efficient and turns less random, but they don’t expand the explorable territory. We’re upgrading the Roomba’s sensors and battery, not giving it a map or new rooms.

Eric S. Raymond nailed a clear symptom recently: LLM novelty friction is about to make adopting new programming languages prohibitively expensive. Who builds the critical mass of high-quality code examples to bootstrap fluent LLM support for a new language with fresh paradigms? Not LLMs—they lack the corpus to generate it reliably. Humans hand-writing it without heavy LLM assistance? In another six months, that’ll feel like stone-age reversion. The cold-start death spiral locks in the monoculture.

This isn’t new—just accelerated. My career started pre-web-browser: books, journals, slow diffusion across silos. Each connectivity upgrade—web searches, Stack Overflow, now LLMs—thickened corpus gravity and reduced local variation. LLMs crank it 100x by pushing the “right” path proactively before you finish thinking.

The old world wasn’t about reinventing the wheel for fun—it was about 100 (or 1,000) engineers independently hacking across the same terrain without knowing about prior solution, having different constraints, or just plain stubbornness. Most paths were redundant or worse, but the sheer wasteful parallelism guaranteed a wide search. Every so often one path proved dramatically better—shorter, safer, more maintainable—and that winner propagated through natural shoot-outs: benchmarks, war stories, conference papers, code-sharing.

Today, corpus gravity + LLMs collapse most of that parallelism into a single high-probability distribution. We get faster convergence on “good enough,” but we lose the distributed search that once surfaced the unexpectedly better move. The shoot-out is now internal (ToT branches, reflection loops) or across a few prompt variants—not across hundreds of human minds exploring truly separate trajectories.

Likely Outcomes

Implications for Software Engineers

This shift isn’t doom—it’s a reallocation of where real leverage lives.

As a 1990s “time traveler”—someone who started in pre-web silos with books, journals, and local reinvention—I’ve got a unique comfort level in those badlands. Less shock when the LLM hits the wall; more instinct for when to go offline and derive from scratch. People like me might not dominate volume, but we could seed the next mutation wave—if the rest of us notice before it’s too late.

What about you? In your workflows, are you mostly raising the shared remix floor… or venturing where the Roomba can’t follow? Drop thoughts below.

Image: Custom Grok Imagine remix inspired by 2009 Roomba Art long-exposure photos from Flickr (IBRoomba series and similar). Original inspiration style available on Flickr.