The Shift of Theseus — Toy Bit Provenance Abstract Domain

CF Bolz-Tereick extends PyPy's Toy Optimizer with a bit provenance abstract domain that tracks where each bit of a value came from, letting the JIT recognize shifts, masks and identities across instruction sequences that a known-bits domain misses, with transfer functions, rewrite extraction and an evaluation on Pydrofoil and PyPy.

Research · Compilers · Python · Programming

Ship Your Interpreter

Basis researchers show how LLMs can invent a programming language, write an interpreter, and prove that the interpreter follows the language's rules—arguing that shipping a verified interpreter is becoming a practical unit of AI-generated software, not just generated code snippets.

Research · AI · Programming · Research · Software Engineering

The geometric model of maintenance

Using git history labelled as new development or maintenance, kqr tests James Shore's rule that each person-month of code induces 10 days of maintenance in year one and 5 days a year after, finds it does not track real projects like tmux, and proposes a geometrically decaying model whose fitted totals range from about 1.5x maintenance per unit of new work for nginx to 5.3x for Neovim.

Research · Software Engineering · Statistics · Programming

Two-Stack Sliding-Window Aggregation

An aggregation is some kind of summary of a set of data. This can be the sum, length, minimum, etc. It is quite common to want to calculate such a summary repeatedly, e.g. “the maximum noise level in dB for the past 30 seconds” for a nuisance detector. In such a case we say there is a sliding window over our data, and we want to aggregate over our window.

Research · Programming · Algorithms · Computer Science · Software Engineering

Bez: Generating a browser engine from specs and testsA generated web rendering engine verified against Chromium, Firefox, and WebKit

Bez generates Rust web-engine code from specifications, admitting candidates only when three shipping browsers agree on geometry—aiming for complete or content-scoped engines that update by regeneration.

Research · Open Source · Web Development · Research · Programming

Tokenization: A Survey for Modern NLP

A comprehensive survey by 32+ tokenizer researchers covering subword algorithms, multilingual pitfalls, evaluation, theory, security, and alternatives—framing tokenization as a first-class bottleneck in the LLM era.

Research · AI · LLMs · Research · Machine Learning

Comparing Muon, NorMuon and AdamW for Fine-tuning a Dense Retriever

Qingcheng Zeng gives Muon and NorMuon the same tuning budget as AdamW when fine-tuning a contrastively pretrained dense retriever: lower training loss, no BEIR win. Learning rate and transfer matter more than the optimizer.

Research · Machine Learning · Research · LLMs · Benchmarks

SWE-sweep: Can Agents Autonomously Find and Fix Bugs?

Meta Superintelligence Labs and academic collaborators introduce SWE-sweep: agents must discover and repair latent bugs across 100 real repositories (~4.1k bugs) with no issue hints—early leaders resolve under 5%, highlighting bug finding as the hard part.

Research · AI Agents · Benchmarks · Research · Programming

An Empirical Study of Harness Design for Coding Agents

Fan et al. ablate planning, action space, and context management in a fixed coding-agent loop across 176 SWE-Bench/Terminal-Bench settings, finding when context management, planning, and predefined tools help—and when bash-only is enough.

Research · AI Agents · AI · Research · Machine Learning

Project HydraFusion: Frontier quality via multi-model orchestration

In controlled offline evaluations, HydraFusion’s selective coding workflows matched or exceeded the evaluated Opus 5 baseline while reducing estimated cost through multi-model orchestration.

Research · AI · LLMs · Developer Tools · Programming

Developing provably correct Rust code with Verus

Many open-source and industry software projects, including several here at Amazon, are embracing the Rust programming language, since it provides performance and flexibility similar to that of the C programming language, while its clever type system automatically prevents a variety of bugs and security vulnerabilities. The result is fast code that's more correct and secure than average.

Research · Rust · Research · Security · Programming

Semantics for 2D Rasterization

Kulkarni, Whiting, and Panchekha introduce μSkia—a Lean-mechanized formal semantics for Skia 2D graphics—and an optimizer that speeds rasterization ~18.7% on Chrome-derived Skia programs while proving replacements correct.

Research · Research · Performance · Programming · Hardware