DATA SCIENTIST · ML RESEARCHER

Amit Aminov

Building trustworthy AI systems.

Machine learning, statistical modeling, LLM evaluation, and formal reasoning — with a focus on systems whose results can be trusted.

Amit Aminov

About

I’m a data scientist and ML researcher with a physics foundation (B.Sc. through Bar-Ilan’s program for youth gifted in mathematics) and years of applied quantitative work. I led an Operations Research and Data Science team in Unit 8200 — hiring, mentoring, and shipping end-to-end ML pipelines — then built statistical models in the IAF’s Operations Research Branch, work recognized with the Israel Defense Prize. In my research M.Sc. at the Hebrew University I work on machine learning for formal reasoning: fine-tuning LLMs to prove theorems in Lean 4, where a verifier, not a leaderboard, decides what counts. Across all of it I build ML systems with careful evaluation, reproducible experiments, and statistically grounded analysis — I try not to trust a number until I understand how it was produced.

  • 2024–Present IAF Operations Research Branch · Israel Defense Prize
  • 2023–Present M.Sc. Computer Science (research), Hebrew University of Jerusalem
  • 2022–2024 Unit 8200 · Operations Research & Data Science team lead
  • 2018–2021 B.Sc. Physics, Bar-Ilan University (gifted-in-math program)

Featured projects

  • Bar chart: a goal-blind frequency sampler proves 26.2% of miniF2F versus 49.6% for a 7B neural prover under the same search budget.

    Generated Formal Theorem Proofs in Lean

    Goal-blind baselines that measure how much of a neural theorem prover’s success is reasoning versus corpus tactic frequency.

    Problem
    Neural provers are rarely compared against a simple baseline, so it’s unclear how much of their success comes from reasoning about the goal versus favoring tactics common in the training corpus.
    Method
    A goal-blind sampler that replays only Mathlib4 tactic frequencies — never reading the statement or proof state — run under the same best-first search budget as the neural prover.
    Result
    A 16,850-parameter frequency table clears 26.2% of miniF2F-test (64/244) versus 49.6% for a ~7B neural prover at the same budget — roughly half the prover’s rate from a floor it is almost never measured against.

    Stack Python · Lean 4 · Mathlib · PyTorch · best-first search

    • LLMs
    • Statistics
  • Screenshot: the Agentic AI Researcher dashboard — a 3D neural-mesh orb above the title, with 252 papers ingested, 47 reproduced, 223 animated, and searchable paper cards showing per-paper figures, tests, and full/partial/minimal verdicts.

    Agentic Research Advisor

    An autonomous agent that reproduces ML papers and is graded on the artifacts it leaves on disk, not on what it claims.

    Problem
    Autonomous coding agents will narrate success they never achieved, so running them unattended is a problem of accountability, not capability.
    Method
    A harness that treats on-disk artifacts as the only source of truth, scoring what each run actually produced rather than the agent’s self-report — so incomplete runs and honest negatives become first-class outcomes.
    Result
    A searchable reproduction dashboard; as of July 2026, 252 papers ingested and 47 reproduced with full / partial / minimal verdicts backed by per-paper figures and tests.

    Stack Python · LLM agents · pytest · static dashboard

    • LLMs
    • Engineering
  • Animation: 3D density surface of a bivariate Gaussian while the camera orbits and the correlation sweeps from -0.85 to +0.85 and back; the surface squeezes onto a diagonal ridge and the peak rises as 1 over the square root of 1 minus rho squared, with a live rho and peak-height readout.

    Gaussian Geometry

    Turns three widely-taught covariance “facts” into exact, unit-tested statements.

    Problem
    Covariance is the most-taught, least-understood object in data science, and its geometry hides traps practitioners repeat.
    Method
    Closed-form derivations backed by unit tests and animation, in place of eyeball and Monte-Carlo intuition.
    Result
    Rotating a Gaussian and constructing its covariance are the same operation; principal-axis orientation becomes pure noise as the variances equalize; and the “one-sigma” ellipse holds only ~39% of the mass in 2D, not the 68% carried over from one dimension.

    Stack Python · NumPy · Plotly · unit-tested derivations

    • Statistics
  • Animation: an RBF-SVM decision boundary in 2D PCA space morphs from an underfit near-plane through the gamma-300 sweet spot into 282 memorized islands, while a live readout tracks the regime, gamma, train and test accuracy, boundary length, and region count.

    Decision Boundary Atlas

    Makes SVM overfitting physically visible as the geometry of a decision boundary.

    Problem
    Overfitting is usually argued from the gap between two accuracy curves — hard to see, and easy to miss when validation labels are scarce.
    Method
    A single RBF-SVM kernel-width sweep in 2D PCA space, with the boundary first confirmed two independent ways as a consistency check.
    Result
    Added flexibility stretches and fragments the boundary into hundreds of isolated islands exactly as test accuracy turns over — boundary complexity as an early warning for memorization.

    Stack Python · scikit-learn · PCA · Matplotlib

    • Machine Learning
    • Statistics
  • Animation: a Technical Interviewer mock session. A 3D avatar interviewer poses a technical question about profiling a pandas pipeline for bottlenecks; the candidate answers and the answer is scored on the rubric. Voice-driven, English and Hebrew. (The candidate shown is an AI stand-in used for the demo.)

    Technical Interviewer

    An adaptive voice mock interview that trains you for the real thing — tailored to your target role and seniority, it asks role-planned questions, holds a real spoken back-and-forth, and does what real interviews never do: scores every answer and hands back a readiness report and study plan. Bilingual (EN/HE); runs fully offline with no API key.

    Problem
    Real technical interviews are scarce and give no feedback: an average corporate opening draws ~250 applicants, ~4–6 are interviewed and one is hired (Glassdoor), and ~94% of candidates who want post-interview feedback never get any. There’s nowhere realistic to rehearse a spoken, role-specific interview and learn from it.
    Method
    A voice-driven mock interviewer tailored to role (Data Scientist / Algorithm Researcher / AI Engineer) and seniority (Junior → Staff/Lead): it plans role-specific questions, listens with real-time barge-in in EN and HE, asks follow-ups and hints, and scores every answer on an 8-metric rubric into a readiness report and cross-session study plan. Production-hardened — every dependency degrades to a deterministic offline engine and the loop resists prompt injection — so it runs fully offline with no API key.
    Result
    A role- and seniority-tailored mock interview that gives the rubric feedback and study plan real interviews never do — resilient, prompt-injection-aware, fully offline, and deterministically testable (221 tests).

    Stack FastAPI · React · Gemini · FAISS + MiniLM RAG · pytest

    • Engineering
  • Screenshot: TripWise ‘South Italy’ trip (23 Sep – 1 Oct 2026) — a map of southern Italy beside trip cornerstones: Plan, Attractions, Yummy, Hotels, Flights, Events, Prices, Mood.

    TripWise

    I built TripWise quickly with an AI-assisted (vibe-coding) workflow to plan an autumn trip to Italy with my girlfriend, and it reframes couples’ trip planning as a decision-integrity problem so the first opinion can’t anchor the second.

    Problem
    Shared decisions are distorted by anchoring: the first partner to voice a preference biases the other.
    Method
    Each partner rates options blind; both sets reveal only once everyone has rated everything — and the rule lives in a Postgres row-level-security policy and trigger, not the UI.
    Result
    No client or future frontend can peek early, because the integrity invariant is enforced in the database rather than the interface.

    Stack Next.js · TypeScript · Postgres (row-level security)

    • Engineering
  • Chart: a shuffled split leaks near-duplicate rows and inflates macro-F1 by 21 to 62 points to near-perfect scores for every model, versus an honest chronological split.

    Room Occupancy

    Shows how a random train/test split manufactures skill out of time on sensor data.

    Problem
    With sensor readings taken every ~30 seconds, a shuffled split drops a near-duplicate of almost every test row into training and inflates the score by tens of macro-F1 points.
    Method
    Compared the shuffled split against an honest chronological holdout — trained on the past, tested on a genuinely later window.
    Result
    Evaluated honestly the task is far harder and shaped by drift between sessions: a simple generative model (QDA, macro-F1 ~0.77) transfers, while tuned tree ensembles built on absolute thresholds do not.

    Stack Python · scikit-learn · QDA · signal processing

    • Statistics
    • Signal Processing

Research focus

My research is on machine learning for formal reasoning. I fine-tune LLMs to prove theorems in Lean 4 using GRPO, with the Lean verifier itself supplying the reward: a proof either checks or it doesn’t, so the model cannot be rewarded for sounding right. Training runs on a university GPU cluster against Mathlib-scale tactic data, measured against the goal-blind frequency baselines from Generated Formal Theorem Proofs that any learned policy has to beat at a shared search budget.

The same discipline runs through the rest of my work: chronological splits instead of shuffled ones, frequency-table baselines instead of only model-versus-model comparisons, artifact-scored reproductions instead of agent self-reports, and closed forms in place of Monte-Carlo intuition. It also shows up as system design — invariants placed where they cannot be bypassed. The goal throughout is evaluation you can trust and systems whose results hold up under scrutiny.

Skills

Machine Learning & Data Science
Deep learning, reinforcement learning, gradient boosting, anomaly detection, unsupervised learning, feature engineering; PyTorch, TensorFlow, scikit-learn, XGBoost, SHAP
LLMs & Evaluation
LLM fine-tuning (LoRA, GRPO), RL with verifier rewards, agentic and tool-use pipelines, Hugging Face, benchmark and baseline design, honest-evaluation methodology
Statistics & Optimization
Statistical modeling, experimental design, honest evaluation splits, uncertainty and simulation, mathematical optimization, resource-allocation / operations-research modeling
Formal Methods & Lean
Lean 4, Mathlib, best-first proof search, verifier-based reward design, theorem-proving evaluation
Engineering & Tooling
Python, pytest, Git, Linux, HPC clusters (Slurm), FastAPI, reproducible pipelines, graceful degradation architecture
Data & Infrastructure
SQL, Oracle Client, MongoDB, Postgres (row-level security), GPU-cluster training, dashboards