About D
I fix systems that are collapsing under their own weight.
Recent projects:
1. I replaced a fragile Node.js image stack with a go-based transcoding cache and minimal dependencies (ipfs-lite, libvips and ffmpeg). Features include:
- Animated GIF → MP4 conversion
- Prioritising of requests to reduce latency
- Multiple IPFS gateways with direct IPFS interaction as fallback – no need for extra IPFS gateway
2. I wrote an extension for PostgreSQL to handle 256-bit integers
- Hex representation
- Summation, addition, comparison operators
- Uses AVX2 for optimised conversions.
- Similar plugin written for SQLite.
3. An extractor for freezer files from go-ethereum.
- Written in zig with single dependency.
- Full NFT ownership list in ~20 minutes.
- Optimised server based on Radix Tries.
- Impact: ~0.5ms vs 10s latency (20000x)
4. Major cleanup of a solidity smart contract.
- Pushing the single contract size limit with massive gas fees.
- Identified and fixed multiple potential reentrency attacks.
- Reduced storage by passing data and working against a hash.
- Added gas-reducing safety-optimized batch calls.
- Simplified maths using fixed-point arithmetic.
5. WebAssembly module written in Zig.
- Deployed in Postgres, on Frontend and on Backend (for Server-Side Rendering).
- Updates reactive svelte values.
- All memory allocation up front.
- Custom binary file format enables loading straight into memory.
- Before: 200ms UI jank; after: overlooked by the profiler.
My most recent work has been around Ethereum-centred projects, but the skills I bring are universal.
English
Native or bilingual
French
Basic
Remote only
Primarily works remotely
Experience
- DPWM InformatiqueDéveloppeur full-stackTECHJanuary 2021 - Today (5 years and 5 months)Guingamp, FranceI’ve worked on a long list of projects, including:
- Beautifully typeset hundred-plus-page programatically-generated reports using Python, SQLite and ConTeXt.
- An invoicing app to be deployed on the Sandstorm platform
- A 10kB Webassembly module that replaced a bug-ridden 2MB javascript bundle, vastly improving page load and customer UX.
- A PostgreSQL extension using C and Zig to handle huge numbers.
- Low-latency in-database typescript code to replace high-latency application code.
- An SQLite extension to provide functions related to big numbers.
- Writing and testing smart contracts for Ethereum.
- A high-concurrency image and video cache and transcoding pipeline using Go, FFmpeg and ipfs-lite.
- Automatic document generation and low-code solutions for a small animal charity.
- CarrHolmAccounts and AdministrationMEDICALJuly 2012 - August 2020 (8 years and 1 month)Prestatyn, United KingdomI held several positions at a small retirement home. I was responsible for documentation, compliance, and employee integration. I was also responsible for all computer and telephone systems on a limited budget. I also was able to experiment with improved workflows in relation to staff rostering.
- The Universiy of EdinburghDéveloppeurRESEARCHJuly 2010 - July 2012 (2 years)Edinburgh, United KingdomI undertook a series of interesting summer projects under a researcher at the University of Edinburgh. I worked on the RIVET analysis framework and YODA analysis objects, mainly in Python and C++. I developed Python bindings for YODA. I significantly improved the performance of histogram binning; the approach I adopted is still used in production today. I also worked on a scientific plotting tool.
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Education
- Physics (MPhys)University of Edinburgh2012Physics with Integrated Masters. Final project studied Statistical Physics models on random undirected graphs.