Hello, world. I'm

Viraj Nistane

Data Scientist & Research Engineer

Nice, France

PhD in Theoretical Physics · Building production-grade data pipelines, ML models, and scientific computing systems.

About

I'm a Research & Data Engineer with a PhD in Theoretical Physics from the University of Geneva, with hands-on experience building production-grade data pipelines, ETL routines, and scientific computing systems.

My background spans cosmological simulations, Bayesian analysis, deep learning for radio astronomy, and modern data engineering practices — bridging the gap between rigorous research and scalable software.

I'm skilled in workflow orchestration, data quality/observability, and mathematical modelling, with a track record of turning complex data into actionable insights across academic and industry settings.

JSPS Fellowship (FY2021)

Japan Society for the Promotion of Science — Strategic Program Research Fellow in Japan

Quick Facts

  • LocationNice, France
  • NationalityIndian
  • LanguagesEnglish, Hindi, Marathi, French
  • Emailnato.viraj@gmail.com

Projects

alexiAId

Emotion Translator — Tough Tongue AI

Production-ready emotion translation and coaching app for alexithymic individuals — built with Next.js 15, TypeScript, Firebase, and the Tough Tongue AI API (implemented at Tough Tongue AI). Features an AI emotion coach, interactive assessments, emotion journaling, progress dashboard, and an admin analytics panel.

Next.jsTypeScriptFirebaseTough Tongue AITailwind CSSZustand

EuclidClusterViz

Data Quality-Control Platform · Euclid Mission

User-oriented data QC platform for the Euclid mission, streamlining development and production data access for scientific users. Features modular pipelines, self-service documentation, and CI/CD integration with GitLab & Jenkins.

PythonGitLab CI/CDJenkinsDockerData Quality

SERENEt

Deep Learning for Radio Astronomy

Co-developed SERENEt, a deep learning framework using TensorFlow/Keras to recover astrophysical signals from contaminated radio images. Included building structured training datasets by extracting and parsing data from the GLEAM-MWA online catalog.

TensorFlowKerasDeep LearningRadio Astronomy

HIRAXmcmc

Python Package

Open-source Python package for efficient Bayesian analysis and MCMC-based parameter forecasting for HIRAX cosmology experiments. Enables simulation-driven survey configuration comparisons.

PythonMCMCBayesianOpen Source

Collaborations

ESA Euclid Mission

European Space Agency · CNRS

Contributing to ESA's Euclid space telescope mission as a CNRS Research Software Engineer at Observatoire de la Côte d'Azur. Developed modular scientific data pipelines and a PPO framework for dependency-aware workflow orchestration.

CosmologyData PipelinesCI/CDPythonJenkins

HIRAX

Hydrogen Intensity Real-Time Analysis eXperiment

Contributed to the HIRAX radio telescope project — a 256-element interferometric array designed to detect dark energy through 21-cm hydrogen intensity mapping. Developed the HIRAXmcmc Python package for Bayesian parameter estimation and led cosmological simulation-driven forecasting studies.

Radio AstronomyBayesian AnalysisPythonHPC

SKA-CH

Square Kilometre Array Switzerland

Member of the Swiss consortium for the Square Kilometre Array (SKA) — the world's largest radio telescope. Involved in 21-cm signal analysis, foreground removal research, and Science Data Challenges.

21-cm CosmologySignal ProcessingResearch

Experience

Data Engineer · Tough Tongue AI

Remote

05/2025 - Present

ETL pipelines (NoSQL → PostgreSQL), workflow orchestration with Prefect/Cronitor, pipeline observability, and Marimo dashboards for product and operations analytics.

PythonPostgreSQLPrefectCronitorMarimoETLNoSQL

Research Software Engineer · Observatoire de la Côte d'Azur (CNRS) (ESA's Euclid Mission)

Nice, France

10/2024 - Present

Built EuclidClusterViz (data QC platform), modular scientific data pipelines, CI/CD integration with GitLab & Jenkins, and a PPO framework for dependency-aware workflow orchestration.

PythonGitLab CI/CDJenkinsDockerData PipelinesEuclid

Doctoral / Post-doctoral Researcher · Université de Genève

Geneva, Switzerland

08/2019 - 09/2024

Simulation-driven cosmological forecasting, Bayesian analysis (HIRAXmcmc package), 30-38x improvement in reconstruction noise via novel statistical estimator for weak (lensing) signals from noisy spatial density data, and co-developed SERENEt deep learning framework for radio signal recovery.

PythonTensorFlowKerasBayesian AnalysisHPCSlurmMCMC

JSPS Research Fellow · Nagoya University Cosmology Group

Nagoya, Japan

Jun 2022 - Sep 2022

Cosmological signal analysis research under the JSPS Strategic Program Fellowship.

CosmologyPythonResearch

Education

Ph.D. in Physics

Université de Genève

Geneva, Switzerland

Aug 2019 - Jun 2023

Department of Theoretical Physics. Focus on cosmological perturbation theory, CMB, galaxy surveys, and 21-cm radio experiments.

M.Sc. in Physics

Ludwig-Maximilians-Universität München

Munich, Germany

Sep 2016 - Apr 2019

Specialisation in theoretical and mathematical physics.

B.Tech. in Engineering Physics

Indian Institute of Technology Delhi

New Delhi, India

Jul 2012 - May 2016

Foundation in applied physics, mathematics, and engineering fundamentals.

Skills

Programming

PythonSQLNoSQLBashGitDeep LearningMachine Learning

Libraries & Frameworks

TensorFlowKerasPandasNumPySciPyMatplotlibPlotlySQLAlchemyPrefectPyMongoPySparkDeltaLakeAsyncioPytestMarimoDatabricks

Infrastructure & DevOps

DockerJenkinsGitLab CI/CDSSHSlurmOpenMPIGPU ProgrammingAgile

HPC & Distributed Systems

Parallel ProgrammingDistributed SystemsHPCGPU Programming

Data & Analytics

ETL PipelinesData QualityStatistical AnalysisMathematical ModellingBayesian AnalysisData Visualisation

Languages

English (C2)Hindi (C2)Marathi (C2, Native)French (B1)German (A1)

Publications

Journal Articles

01

HIRAX: Cosmology Simulations and Forecasts

Viraj Nistane et al.

In preparation

02

Square Kilometre Array Science Data Challenge 3a: foreground removal for an EoR experiment

A. Bonaldi, P. Hartley, R. Braun, S. Purser, A. Acharya et al.

arXiv:2503.11740 [astro-ph.IM]

03

Deep learning approach for identification of HII regions during reionization in 21-cm observations — III. image recovery

Michele Bianco, Sambit K. Giri, Rohit Sharma, Tianyue Chen, Shreyam Parth Krishna et al.

arXiv:2408.16814 [astro-ph.CO]

04

Hydrogen Intensity and Real-Time Analysis Experiment: 256-element array status and overview

Devin Crichton et al.

J.Astron.Telesc.Instrum.Syst. 8 (2022), 011019

arXiv:2109.13755DOI: 10.1117/1.JATIS.8.1.011019
05

An estimator for the lensing potential from galaxy number counts

Viraj Nistane, Mona Jalilvand, Julien Carron, Ruth Durrer, Martin Kunz

JCAP 06 (2022) 06, 024

arXiv:2201.04129DOI: 10.1088/1475-7516/2022/06/024
06

CMB sky for an off-center observer in a local void. Part I. Framework for forecasts

Viraj Nistane, Giulia Cusin, Martin Kunz

JCAP 12 (2019), 038

arXiv:1908.05484DOI: 10.1088/1475-7516/2019/12/038

Conference Proceedings

01

The Hydrogen Intensity Real-Time Analysis eXperiment: Overview and Status Update

Anthony Walters, Keshav Bechoo et al.

2024 18th European Conference on Antennas and Propagation (EuCAP)

DOI: 10.23919/EuCAP60739.2024.10501639
02

Design and implementation of a noise temperature measurement system for the Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX)

Emily R. Kuhn, Benjamin R.B. Saliwanchik, Maile Harris, Moumita Aich, Kevin Bandura et al.

Proc. SPIE 11445, Ground-based and Airborne Telescopes VIII, 114452Z (2021)

arXiv:2101.06337DOI: 10.1117/12.2560270
03

Mechanical and Optical Design of the HIRAX Radio Telescope

Benjamin R.B. Saliwanchik, Aaron Ewall-Wice, Devin Crichton, Emily R. Kuhn, Deniz Ölçek et al.

arXiv:2101.06338 [astro-ph.IM]

Teaching

Teaching assistant at the Department of Theoretical Physics, Université de Genève.

CourseInstructorSemesterRole
General RelativityProf. Martin KunzAutumn 2019–20Teaching Assistant
Quantum Mechanics IProf. Martin KunzSpring 2019–20Teaching Assistant
General RelativityProf. Martin KunzAutumn 2020–21Teaching Assistant
Quantum Mechanics IProf. Martin KunzSpring 2020–21Teaching Assistant
Mechanics IIProf. Lucas Lombriser / Prof. Ruth DurrerAutumn 2020–21Teaching Assistant

Contact

I'm open to opportunities in data science and engineering, and software engineering. Whether you have a question or just want to say hi, feel free to reach out!

Nice, France (open to remote & relocation)