About

I’m Soichi Hayashi, a full stack software engineer based in Bloomington, IN, with two decades of experience making high-performance computing and large-scale data platforms accessible to the people who depend on them — researchers, scientists, and analysts.

Much of my career has been spent building software for large international scientific organizations and projects — work spanning astronomy (telescope data pipelines for the WIYN Observatory), high-energy physics (grid computing for CERN and FermiLab through the Open Science Grid), and neuroscience (the brainlife.io platform). Today I bring that same focus on scalable, dependable systems to quantitative finance.

That range is the throughline I’m proudest of: the same core work — making massive datasets and computing accessible to people who aren’t systems experts — applied across telescopes, particle detectors, brains, and portfolios. Along the way my research has been cited 800+ times (h-index 10), including a first-author paper in Nature Methods, and I’ve contributed to open-source neuroimaging tools used by labs around the world.

Experience

Senior Full-Stack Software Engineer — Acadian Asset Management

2022 – present

Modernizing Acadian’s internal portfolio analytics platforms so asset managers can quickly analyze portfolio return attributions and other metrics, helping them better manage more than $200B in assets under management.

Lead Software Engineer — Indiana University, Psychological & Brain Sciences

2017 – 2022

Technical lead and senior engineer for brainlife.io, an open-source cloud platform for neuroimaging data analysis.

Designed a highly scalable backend handling hundreds of researchers running millions of jobs per year, with seamless access to national supercomputers, private clouds, and institutional HPC.
Validated the platform for reproducibility and scientific utility across four data modalities and 3,200 participants (published in Nature Methods).
Operated the production service stack and built highly available infrastructure.
Developed flagship neuroimaging visualizers and GPU-enabled native UI streaming services.
Managed sub-projects and mentored junior developers.
Served as co-PI on NSF/NIH awards totaling over $3.1 million.
Contributed to open-source projects including nibabel, fMRIPrep, vistasoft, and DIPY.

Senior Software Engineer — Indiana University, Scientific Applications & Performance Tuning

2015 – 2017

Led development of high-profile science gateways across astronomy, bioinformatics, and geology.
Built a radiology QC system for IU Medicine with complex real-time logic.
Consulted researchers on scientific computing and software development.

Software Architect / Engineer — Indiana University, Open Science Grid

2008 – 2015

Designed and developed central services for the Open Science Grid:

Resource topology database and visualization services.
A ticket submission and synchronization system across support organizations.
IGTF-accredited x.509 certificate issuance and revocation management.
A user-friendly configuration-management UI for perfSONAR (as a PWA).

Senior Software Engineer — Acxiom / Citigroup

2007 – 2008

Built a web application for employee access and entitlement review, enabling account managers to identify security risks and comply with management policy.

Software Developer — Acxiom / Business Intelligence & Analytics

2004 – 2007

Developed ETL components for a business intelligence platform for EMC².
Cut a SAS credit-scoring workflow from 8 hours to 15 minutes for Capital One.
Engineered solutions for Discover Financial and built the company’s first grid-only data warehousing pipeline.

Solutions Developer — Acxiom / Market Management Applications

2001 – 2004

Developed campaign-management applications for media and publishing clients including Elsevier and Roedel, enabling complex consumer-demographic queries that saved tens of millions of dollars in marketing costs.

Selected publications

Hayashi, S., Caron, B.A., Heinsfeld, A.S. et al. “brainlife.io: a decentralized and open-source cloud platform to support neuroscience research.” Nature Methods 21, 809–813 (2024). doi:10.1038/s41592-024-02237-2
Avesani et al. “The open diffusion data derivatives, brain data upcycling via integrated publishing of derivatives, and reproducible open cloud services.” Nature: Scientific Data (2019). doi:10.1038/s41597-019-0073-y
Halchenko et al. “DataLad: a distributed system for joint management of code, data, and their relationship.” JOSS 6(63), 3262 (2021). doi:10.21105/joss.03262
Levitas, D., Hayashi, S. et al. “ezBIDS: guided standardization of neuroimaging data interoperable with major data archives and platforms.” Scientific Data 11, 179 (2024). doi:10.1038/s41597-024-02959-0
“Classifyber, a robust streamline-based linear classifier for white matter bundle segmentation.” NeuroImage (2020). doi:10.1016/j.neuroimage.2020.117402
Contributor to widely-used open-source neuroimaging software including nibabel, DIPY, fMRIPrep, and DataLad.

See my Google Scholar profile for the full list (800+ citations, h-index 10) across neuroscience, astronomy, and grid computing.

Skills

Languages: JavaScript/TypeScript, Python (Pandas, Numba), Java, PHP, C/C++, C#
Frontend: React, Vue, Angular, Three.js, WebGL, Electron, CSS/Bootstrap
Backend: Python/FastAPI, Node.js/Express, PHP/Zend, JavaEE, Firebase
Databases: MongoDB, Snowflake, MySQL, Postgres, MSSQL
DevOps: Docker, Singularity, Karpenter, Nginx, LVS/Keepalived, Sensu/Grafana, ELK, pm2
Cloud / OS: AWS, Azure, GCP, Jetstream/OpenStack, VMware, Linux (RHEL, Ubuntu), Windows
Misc: RabbitMQ, Redis, TensorFlow/Keras, git, ssh/x.509

Education

BS, Computer Science — Henderson State University (2001)
BS, Physics — Henderson State University (2001)
Non-degree program — Indiana University (2020 – 2022)

Awards

Employee of the Year, 2021 — Crisis Technology Innovation Lab
First “Grid-Only” Solutions Award, 2006 — Discover / Acxiom
Associate Awards (2001 – 2008) and People’s Choice Award (2004) — Acxiom

Beyond work

Outside of engineering I’m usually on an evening run (chasing a 10k finish), at the piano or guitar writing music, or tinkering with smart-home automation.

Languages

English · Japanese (native)