John Ruelas — Staff Software Engineer
About
Hi, I'm John.
I'm a software engineer focused on backend systems and data infrastructure. Currently, I work as a staff software engineer at Ramp, where I joined the accounting platform team in 2026.
I have worked in software for more than a decade, but my background began in hardware and neuroscience. As a student, I built an open-source 64-channel electroencephalography (EEG) system, designed to replace more expensive commercial systems. I published all of the design files publicly. That work led me to found a startup building wearable EEG headsets. I later spent a few years in a biophysics laboratory at Cornell University, where I designed the sampling platform and interface layer for CMOS sensor chips capable of recording electrochemical signals from single living cells. I co-authored three peer-reviewed papers from that research.
My work shifted from hardware to software over the following years. Since then I have built data platforms and distributed backend services, and worked extensively on large-scale data ingestion and processing. I have also led engineering teams responsible for that infrastructure.
I live in upstate New York, where I spend most of my free time building furniture in my woodshop and fostering dogs.
Experience
Download full résumé (PDF)-
Staff Software Engineer
Apr 2026 – PresentRamp
Building @ Ramp. Member of the accounting platform team.
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Senior Software Engineer, Team Lead
Oct 2022 – Apr 2026Jellyfish
Lead engineering across the infrastructure and data ingestion teams after being promoted to team lead in 2024. Directed the build-out of the company's data platform, including a migration to Databricks and PySpark and an LLM-powered integrations layer that scaled the product from 3 integrations to more than 50 and reduced P99 query times on customer metrics by 98%. Established the organization's observability and on-call practices, cutting incident detection time by over 95%.
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Senior Software Engineer
Jun 2021 – Oct 2022Capsule
Built core systems for pharmacy operations. Led development of the patient-communication service spanning mobile, web, text, and voice, reaching tens of thousands of patients within a 500ms SLA. Migrated the operations dashboard backend from Kotlin and DynamoDB to Python and Redis.
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Senior Software Engineer, Team Lead
Aug 2019 – Jun 2021Smart Start
Owned the test systems validating breathalyzer and ignition-interlock hardware. Migrated a legacy Windows library to Linux, consolidated eight separate device-flashing tools into a single CLI and web interface, and built the manufacturing analytics dashboards. Took over two at-risk projects and delivered both on schedule, reducing manufacturing costs by more than 30%.
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Founder / Lead Engineer
2013 – 2018MYWARE
Founded and led an EEG wearable-technology company. Designed the wireless headset hardware and the firmware for lossless real-time streaming, built the desktop application, and developed a Python signal-processing pipeline that applied reinforcement learning to biofeedback, spanning the full stack from circuit board to software.
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Hardware & Software Engineer
2015 – 2018Cornell Biophysics Lab / ExoCytronics
Developed CMOS chips for massively parallel cyclic voltammetry in Dr. Manfred Lindau's laboratory, building the data-acquisition hardware and the analysis pipeline for detecting single-cell exocytosis events. This research produced the publications listed below.
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Research Assistant
2015The Shoulders of Giants
Designed a low-cost TI-MSP430 biosignal acquisition platform from the ground up, then developed and taught a two-week biomedical engineering program for high-school students.
Publications
- Dorta-Quiñones, Huang, Ruelas, et al. A Bidirectional-Current CMOS Potentiostat for Fast-Scan Cyclic Voltammetry Detector Arrays. IEEE TBioCAS, 2018.
- Huang, Delacruz, Ruelas, et al. Surface-modified CMOS IC electrochemical sensor array targeting single chromaffin cells. Pflügers Archiv, 2018.
- Huang, Ruelas, et al. A CMOS based Sensor Array Platform for Analysis of Exocytosis Events. Biophysical Journal, 2017.
Contact
- GitHub github.com/jruel4
- LinkedIn linkedin.com/in/mywarejohn
- Woodworking woodworking.johnruelas.com