Where Did the Variability Go? From Vibe Coding to Product Lines by Regeneration

[Submitted on 17 Jun 2026 (v1), last revised 8 Jul 2026 (this version, v2)]

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Abstract:In vibe coding, an emerging AI-driven paradigm, an LLM generates an entire program from a natural language prompt, but what happens to the variability that traditional software engineering carefully builds into code? To answer this question, we conducted an exploratory analysis on 10 vibe coded C/C++ projects, which suggests that there is near zero in-artifact variability, i.e., at compile- and runtime. All variability decisions are resolved at a single new binding time, generation time, the moment the LLM produces the source code. Rather than treating this as a defect to fix, we propose Variability by Regeneration (VbR), to our knowledge the first product line approach in which the LLM acts as the derivation engine, generating a dedicated, free of dead code binary for each variant from a declarative specification, while a variant dispatcher transparently routes user requests to the matching binary. We formalise VbR, contrast it with classical SPL derivation, and demonstrate its full pipeline on a wc product family. For SPL engineering, variability in AI-generated software belongs in the specification, not in the code.

Submission history

From: Xhevahire Tërnava [view email]
[v1] Wed, 17 Jun 2026 13:10:24 UTC (259 KB)
[v2] Wed, 8 Jul 2026 16:05:35 UTC (258 KB)