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fastml vs lstar

A side-by-side editorial comparison of fastml and lstar — release velocity, themes, recent moves, and the top alternatives to consider.

fastml vs lstar: at a glance

Featurefastmllstar
SectorAnalyticsAnalytics
Velocity score0.05.0
Sparks · 30d00
Top themesautoml, tidymodels, survival analysis, cross-validationsingle-cell-genomics, zarr, wasm, data-formats
Last editorial update51m ago4h ago
WebsiteVisit →Visit →

What is fastml?

fastml added survival modelling and leakage-proof resampling, moving past classification and regression.

A tidymodels-based AutoML wrapper that trains, tunes and compares many engines from one call. The 0.6.x line added engine-specific tuning parameters, class-imbalance handling, early stopping and DALEX-based explainability. The 0.7.5 release is far larger: a full survival analysis task with its own engines, MICE imputation and integrated Brier scoring, plus unbiased nested cross-validation, grouped, blocked and rolling resampling helpers, fold-wise imputation, recipe leakage checks, and a sandbox for user-supplied preprocessing.

Read the full fastml trajectory →

What is lstar?

A single-cell data store commits to Zarr v3 and range-readable hosting across four language surfaces

lstar stores single-cell data behind one C++ core with Python, R and JS/WASM bindings, and ships a browser viewer that reads the store directly. Zarr v3 is now the default on-disk format across all four surfaces, with zstd compression and sharding that packs many chunks into fewer objects. Viewer stores are compressed per field and resolved at chunk granularity, so a hosted viewer fetches only what it displays. The tag stream carries both lstar and lstar-sc releases.

Read the full lstar trajectory →

fastml vs lstar: editorial side-by-side

F
fastml
ANALYTICS
0.0

fastml added survival modelling and leakage-proof resampling, moving past classification and regression.

◆ Current state

A tidymodels-based AutoML wrapper that trains, tunes and compares many engines from one call. The 0.6.x line added engine-specific tuning parameters, class-imbalance handling, early stopping and DALEX-based explainability. The 0.7.5 release is far larger: a full survival analysis task with its own engines, MICE imputation and integrated Brier scoring, plus unbiased nested cross-validation, grouped, blocked and rolling resampling helpers, fold-wise imputation, recipe leakage checks, and a sandbox for user-supplied preprocessing.

◆ Where it's heading

The package is moving from convenience wrapper to something that has to be defensible statistically. Nested cross-validation, fold-wise rather than up-front imputation, and explicit leakage checks are all corrections to the shortcuts that make AutoML easy and its scores optimistic. Survival adds a third task type alongside classification and regression, and it arrived with its own metrics rather than being bolted onto the existing ones. Note the entry body is cut off at 8,000 characters, so the release is larger than what is shown.

◆ Prediction

Expect the remaining survival engines to fill in and the sandboxing of custom preprocessing to tighten, since both were still being iterated on within this same release's commit list.

L
lstar
ANALYTICS
5.0

A single-cell data store commits to Zarr v3 and range-readable hosting across four language surfaces

◆ Current state

lstar stores single-cell data behind one C++ core with Python, R and JS/WASM bindings, and ships a browser viewer that reads the store directly. Zarr v3 is now the default on-disk format across all four surfaces, with zstd compression and sharding that packs many chunks into fewer objects. Viewer stores are compressed per field and resolved at chunk granularity, so a hosted viewer fetches only what it displays. The tag stream carries both lstar and lstar-sc releases.

◆ Where it's heading

The through-line is making a hosted store cheap to read. Sharding addresses the file-per-chunk explosion that makes many-chunk arrays awkward to host; per-field compression with chunk-granular resolution means colouring an embedding by one gene fetches one column rather than an array. The 0.2.x patches are the cost of maintaining four surfaces at once — a WASM heap crash that only browsers exercise, and a count-basis orientation defect where all three surfaces normalized in memory and none owned the on-disk layout.

◆ Prediction

The orientation bug's root cause — no surface owning the on-disk representation while all three normalized in memory — is the kind of gap that usually produces a validation or ownership change rather than another point fix.

Alternatives to fastml and lstar

Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either fastml or lstar.

See all fastml alternatives → · See all lstar alternatives →

Recent activity from fastml and lstar

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 21d agolstarViewer count-basis orientation fixed; existing stores need re-prep
  2. 26d agolstarWASM viewer crash on resizable heaps fixed
  3. 1mo agolstarlstar 0.2.0
  4. 1mo agolstarMeasure state inferred from content, not slot name
  5. 8mo agofastmlVersion 0.7.5
  6. 1y agofastmlEngine-specific tuning, imbalance handling and explainability
  7. 1y agofastmlSingle-workflow evaluation fix
  8. 1y agofastmlVersion 0.5.0

Frequently asked questions

What is the difference between fastml and lstar?

They serve adjacent needs but don't currently overlap on shipped themes. lstar is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is fastml better than lstar?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. lstar is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to fastml?

Top fastml alternatives in Analytics are ranked by recent ship velocity. Browse the "fastml alternatives" section above for the current picks, or visit /alternatives/fastml for the full list with editorial commentary on each.

What are the best alternatives to lstar?

Top lstar alternatives in Analytics are ranked by recent ship velocity. Browse the "lstar alternatives" section above for the current picks, or visit /alternatives/lstar for the full list with editorial commentary on each.