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billdmar/README.md

Hi, I'm William Mar 👋

Electrical & Computer Engineering student at The University of Texas at Austin and a Software Engineer Intern at Amazon. I build across the stack with a focus on low-latency C++ trading systems, quantitative research (options pricing & market microstructure), distributed systems, applied ML + full-stack web, and formally-verified hardware (SystemVerilog / FPGA). I like shipping things that actually run: most of my projects have a live demo, reproducible benchmarks, or a green CI badge — not just a README.

🎯 Seeking Summer 2027 Software Engineering / Quant-Dev internships — low-latency systems & applied ML. 📍 Austin, TX


🛠️ Tech I work with

Python TypeScript Swift C++ C Go Zephyr RTOS Embedded SystemVerilog

React FastAPI PyTorch NumPy SwiftUI Firebase Vite Docker Git


🚀 Featured projects

Each ships with a real test suite and green CI; several have a live demo or fully reproducible benchmarks you can run yourself.

Project What it is Built with
nanobook C++20 NASDAQ TotalView-ITCH 5.0 limit order book + price-time matching engine, engineered like HFT infra: a zero-allocation hot path (proven by a counting-allocator test), O(1) top-of-book via an occupancy bitmap, and a lock-free symbol-sharded pipeline — verified against a std::map oracle over millions of messages, 67.7M-execution fuzzing, ASan/UBSan/TSan, ~99% coverage, and a real 268M-message trading day. C++20 · CMake · GoogleTest · libFuzzer
vol-lab Options-pricing & implied-volatility-surface engine on real Deribit data — four cross-verified pricing engines (Black–Scholes, CRR binomial, Monte Carlo, Longstaff–Schwartz American), SVI smile calibration under no-arbitrage (Durrleman g(k) ≥ 0 butterfly gate), and an IV solver that returns None on vega-collapse instead of a plausible-but-wrong vol. 201 property-based tests, 96% coverage, mypy-clean. Python · NumPy/SciPy · Hypothesis
micro-lab Market-microstructure research platform: independent NASDAQ order-book reconstruction validated to 100% exact transitions over 1,673,089 events, a from-scratch statistics engine golden-tested to 1e-8, purged/embargoed walk-forward CV, and Benjamini–Hochberg FDR control over a pre-registered 17-test family — honest statistics, no PnL claims. 160+ tests, ~97% coverage (≥90% gated). Python · pandas · statsmodels · scikit-learn
quorum Raft consensus + replicated key-value store in Go — a deterministic-simulation core stress-tested over 140,000 adversarial fault schedules (message loss, partitions, crashes), checked for linearizability with Porcupine plus Raft invariant monitors, and go test -race clean — Jepsen / FoundationDB-style verification rigor. Go · Raft · Porcupine · DST
SystemVerilog FIFO Verification Suite Sync, async (dual-clock CDC) & AXI4-Stream FIFOs formally proven with SymbiYosys (BMC + k-induction + liveness), Verilator-simulated to 100% coverage closure, and FPGA-characterized on ECP5 + iCE40. SystemVerilog · SVA · SymbiYosys · Verilator · Yosys/nextpnr
ASL Sign-Language CNN · 🌐 live Real-time American Sign Language recognition running 100% in-browser (MobileNetV2 → ONNX Runtime Web + MediaPipe) behind a full PyTorch training/eval pipeline, with a cross-language TS↔PyTorch numeric parity gate (~5e-7) enforced in CI. Ships an honest cross-dataset accuracy story — 55.5% (59.8% on static A–Y), not the leakage-inflated 96.9% same-dataset figure. PyTorch · ONNX · Next.js · TypeScript
More projects — systems, full-stack, finance & iOS
Project What it is Built with
governor Production-style Zephyr RTOS telemetry-and-control node, verified like safety-critical software: HAL-abstracted drivers, a 100 Hz PID loop, a CRC-framed reliable UART link (ARQ + dedup), and an explicit INIT→RUN→DEGRADED→SAFE_STOP safety state machine — proven with a 16-scenario fault-injection matrix, 178.8M-run libFuzzer+ASan on the parser (zero findings), property tests, 98% coverage, and CI on simulated hardware (QEMU + Renode STM32). Zephyr · C · Renode · QEMU · libFuzzer
Aquify ATX · 🌐 live Full-stack map of 30+ Austin water fountains with Firebase auth, community reviews, and a climate-driven hydration recommendation engine using live weather. 340+ tests, CI green. React · Vite · Firebase · Leaflet
Travel AI · 🌐 live LLM travel-itinerary generator: async REST API with a preference→prompt recommendation engine, response caching, rate limiting, and a multi-step React UI. FastAPI · React · SQLAlchemy · Docker
proforma M&A merger model on a real announced deal (Synopsys/ANSYS) reconstructed from SEC filings — a live-formula Excel model differentially verified to the cent against a from-scratch Python engine, XBRL tie-out to disclosed facts, and an M&A memo. 300 tests, 97.3% coverage. Python · openpyxl · XBRL
Edutok TikTok-style AI learning feed: Gemini-generated flashcards with spaced repetition, gamification, and a never-empty resilience guarantee. 74 tests, CI. SwiftUI · Gemini · Firebase
SafeWalk An AI safety companion that checks in on you while you walk alone at night and escalates to emergency contacts if you stop responding. SwiftUI · Gemini · Core Location · MapKit
PomodoroTimer A polished Pomodoro focus-timer with customizable sessions, a focus-mode lock, stats, and a Firebase leaderboard. SwiftUI · Firebase

📫 Get in touch

LinkedIn Email

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  1. nanobook nanobook Public

    C++20 NASDAQ TotalView-ITCH 5.0 limit order book + price-time matching engine with an HFT-grade verification stack (differential, fuzzing, sanitizers, 98% coverage).

    C++

  2. vol-lab vol-lab Public

    Options pricing & implied-volatility surface engine on real Deribit crypto data — 4 cross-verified engines (Black-Scholes/binomial/Monte Carlo/LSMC), SVI calibration under no-arbitrage, validated a…

    Python

  3. micro-lab micro-lab Public

    Market-microstructure research platform: LOBSTER book reconstruction, verified statistics pipeline, canonical order-flow replication with honest statistics (CIs, HAC, purged CV, FDR). No PnL/tradab…

    Python

  4. quorum quorum Public

    Raft consensus + replicated key-value store in Go — a sans-I/O deterministic core verified by deterministic simulation testing (140k adversarial fault schedules), Porcupine linearizability checking…

    Go

  5. fifo-verification-suite fifo-verification-suite Public

    8 SystemVerilog FIFO designs formally verified (SymbiYosys BMC + k-induction), mutation-tested, FPGA-characterized — green CI

    SystemVerilog

  6. asl-cnn-classifier asl-cnn-classifier Public

    Live in-browser ASL alphabet classifier (Next.js + ONNX Runtime Web) with honest cross-dataset accuracy reporting

    JavaScript