Staff Software Engineer
Ruby on Rails · fintech integrations & payments · learning tools
Jayson Virissimo is a Staff Software Engineer at SUBSCRIBE, where he owns partner integrations for a regulated alternative-investments platform: architecture, compliance rules, data pipelines, incident response, and the partner relationship. He works in Ruby on Rails with Postgres, GraphQL, and React, and likes the parts of financial software that have to be boringly correct: idempotent pipelines, locks and constraints, authenticated webhooks, and tests written before the code.
Before that he managed the checkout and payments team at Tuft & Needle and built messaging features at Handshake. Outside of work he builds learning tools grounded in spaced repetition, most recently Altkata and LedgerLore, native apps for iPhone, iPad, and Mac. He lives in Arizona.
Sole engineer and technical owner of the integrations that connect a private-markets platform to one of the largest US independent broker-dealers and to a major full-service wealth management firm: automated account and team imports, licensing and training checks that gate order entry, and a configuration-driven pipeline so the next partner onboards with little custom code. The first alone serves millions of accounts and more than ten thousand users.
Researched, designed, and shipped a SCORM-based learning management system that gates investment-product access on completed training, with real-time sync to external platforms, plus the pre-order training-verification gate that checks advisors across every organization on the platform.
At Tuft & Needle, first as an engineer and then as engineering manager: payment capture guarded against double charges, fraud screening across Stripe, Affirm, and PayPal, rate limiting on the public API, and e-commerce launches for two additional mattress brands on the same Rails monolith.
Native Apple apps that teach a professional field through short exercises scheduled by FSRS. Sessions end each day, a full hands-free voice mode works while walking or driving, and everything is local-first with optional iCloud sync — no accounts, no tracking.
Learn financial technology
The engineering side of fintech: double-entry ledgers, payment rails (ACH, cards, instant, wire), reconciliation, idempotency, and webhooks — ordered so no term appears before the card that defines it.
686 exercises · 53 topics
Website In App Review
Learn alternative investments
The foundations of alternative investments: private equity, hedge funds, real estate, infrastructure, commodities, structured products, and digital assets, plus the regulatory and tax frameworks around them.
1,728 exercises · 54 topics
I extracted Altkata’s engine into recito, a Swift and Ruby framework for building apps like these, and LedgerLore is built on it. (Not yet open source.)
A Ruby gem that turns your ActiveRecord models into smart flashcards. Add has_deck to a model and get spaced-repetition scheduling — from the classic Leitner system to the modern FSRS algorithm. 42,000+ downloads.
A browser-based platform for practicing 22 classic algorithm problems by making the tests pass in JavaScript, Python, or Ruby — running Ruby and Python entirely client-side via WebAssembly (ruby.wasm and Pyodide).
An interactive tool for building digital logic from NAND gates up to a complete Arithmetic Logic Unit, following the Nand2Tetris curriculum. Write real HDL in the browser with live verification, SVG circuit diagrams, and progressive hints.
A Ruby gem that converts Latin text into phonetic spellings and IPA lexicons so text-to-speech engines (like AWS Polly) can authentically pronounce medieval Latin. 57,000+ downloads.