Chris Willmore

Profile

A senior software engineer with seventeen years of experience delivering key features and API in the Apple ecosystem, and a strong background in type design, music, mathematics, and computer science.

Areas of interest: typography and type design, music and audio, programming languages, compilers and interpreters, languages and international support, music and audio, data compression and indexing, statistical language modeling.

Skills

Proficient in Python, Objective-C, C++, Swift, Bash. Prior experience with Java, OCaml, Ruby, HTML, CSS, Javascript. Familiar with Haskell, Perl, Scheme, Lisp, x86 and ARM assembly, XML, XSLT, PHP, Metafont.

Recent experience includes macOS, iOS, AppKit, UIKit, Core Animation, Core Text, TextKit, Unicode, ICU, Git, Glyphs, Robofont. Previous professional experience includes Subversion, Git, SQLite, OCUnit, LLVM, Clang, Flex, Bison.

Other experience includes Linux, Apache, Phusion Passenger, Ruby on Rails, RSpec, PostgreSQL, MySQL, Pixelmator, LaTeX, Cocoa, GNU Make, Rake, Bundler, OpenGL. Some experience with Django, Windows, Visual Studio .NET, CVS, wxWidgets, OpenType.

Fluent in written Spanish and Portuguese. Experienced in typography and internationalization, including font design and engineering, line breaking, collation, transliteration, tokenization, text layout, and UI localization. Experienced in search methods for optimization problems including branch-and-bound, gradient descent, and simulated annealing.

Work Experience

Letterform Archive, San Francisco, CA 2025–present

Teaching Assistant, Type West

Facilitate the design classes and weekend workshops for Type West 2025’s in-person cohort. Provide students with technical assistance with font-editing software, design critiques, and project guidance.

Glyphs
Robofont
Slack

Apple Inc., Cupertino, CA 2007–2025

Software Engineer, Cocoa 2019–2025

Maintained and extended the text-related components of AppKit (NSTextView, NSTextField, and the NSString/NSAttributedString drawing API) and TextKit 2. Accomplishments include:

integrating TextKit 2 into NSTextView
preparing and co-presenting the “Meet TextKit 2” session at WWDC21
improving the performance of NSTextView when editing large documents
improving the way paragraphs are broken into lines in AppKit, by
- implementing optimal line breaking in the style of Knuth-Plass
- implementing balanced line breaking, which puts a roughly equal amount of text on every line of a paragraph, including the last one
- tailoring line breaking behavior according to language and context
implementing animations and menu items for the Writing Tools feature in AppKit
implementing visually contiguous selection and cursor behavior for bidirectional text
implementing descender avoidance for underlines in Core Text
contributing to animated text in Messages
contributing to text drawing and editing in SwiftUI

Objective-C
Swift
C++
AppKit
Foundation
Core Foundation
Core Graphics
Core Animation
Core Text
Swift
SwiftUI
ICU
XCTest

Software Engineer, iOS Input Experience 2016–2019

Maintained and extended the iOS keyboard and autocorrect system (primarily the QuickPath path-based keyboard). Accomplishments include:

implementing the recognition algorithm behind the QuickPath keyboard on iPhone, which converts a path traced by the user’s finger into a set of candidate words
writing a system for evaluating the quality of the QuickPath keyboard by replaying recorded paths from testers and counting how many of them result in the correct word being inserted into the document
writing a system for training the parameters of the autocorrect model using stochastic hill-climbing
integrating machine-learning-based typing models into QuickPath
improving the autocorrect experience for languages with diacritics and multiple keyboard layouts on iOS, including German, Spanish, and Turkish

C++
Objective-C
UIKit
ICU
Git
Bash
Python
XCTest

Software Engineer, Developer Tools 2014–2016

Maintained and extended the Swift compiler frontend. Accomplishments include:

improving the reliability of the Swift parser and type checker, and expanding the type checker’s regression test suite
improving the quality of the Swift compiler’s error messages when a program fails to type-check
improving the behavior of the Swift parser in interactive contexts, i.e. when parsing code that is in the process of being edited
updating the Swift parser and type checker to reflect changes to the language, including changes to syntax, implicit conversions, overload resolution, and generics instantiation
improving incremental build times for large Swift projects
implementing color and image literals in the Swift parser; this allows programmers to include colors and images directly in their code in Swift Playgrounds
integrating the Swift standard libary’s Set type into the compiler
contributing to the Swift interface of Core Graphics
implementing built-in functions supporting os_log in Clang
assisting Swift’s transition from an Apple-internal project to an open-source codebase

C++
Swift
Objective-C
LLVM
Clang
LLDB
lit
CMake
Ninja

Software Engineer, iOS Keyboard and Text 2011–2014

Maintained and extended the iOS keyboard and autocorrect system. Accomplishments include:

implementing retrocorrection, which allows autocorrect to change more than one word at a time and correct “well see” to “we’ll see” and “new york” to “New York”
integrating next-word prediction and implementing the associated above-keyboard candidate bar
implementing French dynamic accent key support
implementing input transliteration for Tamil input methods (both Anjal and Tamil 99)
writing custom ICU collators for matching user input with autocorrect candidates
integrating autocorrection with the Natural Language framework, including extending and documenting the binary autocorrect dictionary format and designing a custom compression scheme for it
integrating canned responses for the Messages app into the keyboard candidate bar
converting the autocorrect source repository from SVN to Git
fixing several build issues brought about by the autocorrect system’s unique cross-OS needs
adding unit tests and supporting code

C
C++
Objective-C
UIKit
Core Foundation
Core Graphics
Core Animation
Core Text
Unicode
ICU
Python
Bash
SQLite
Xcode
OCUnit

Software Engineer, OS X Software Updates Integration summer of 2007; 2008–2011

Carried out the dual missions of ensuring the quality of OS X software updates and writing the tools to automate said testing. Quality work includes OS-wide bug diagnosis, manual testing, and bug triage. Tools I contributed to include:

an automated pre-submission testing service for OS X software update builds
a test results database, consisting of a Rails/PostgreSQL server and an Objective-C framework client
a service for quickly NetBooting into historical builds of OS X for bug regression
a Ruby library for manipulating remote machines over SSH and SCP
various regression tests for OS X, including kernel extension validation, moveable-apps functionality check, and UI-level tests for Calculator, Script Editor, and TextEdit

Other projects include:

an effort to improve the performance of Colin Percival’s bsdiff tool
a prototype note-taking app which automatically detects and displays cross-references between pages in the notebook
a proof of concept for WYSIWYG inline equation editing in Cocoa’s NSTextView
a search engine for internal projects’ source code

Smaller hacks include:

extending the Python interpreter with Objective-C method invocation syntax, to make Objective-C method calls in PyObjC feel more natural
work toward a general-purpose random-access compression algorithm (eventual goal is efficient file system compression of very large files)
a Python bytecode interpreter in Javascript, which allows Python to run in the browser
a Cocoa app that periodically prompts users to tell it what they are doing and appends it to that day’s page in their VoodooPad instance.

C
Objective-C
Python
Ruby
Bash
PHP
PostgreSQL
MySQL
Ruby on Rails
Sinatra
Lucene
AppleScript Bridge

Arxan Research, West Lafayette, IN summer of 2006

Programmer

Tested Arxan’s software tamperproofing solutions, including reverse-engineering binary x86 and PowerPC code; wrote automated tools to generate patches that neutralized the software protections; wrote parts of the floating-point unit for an x86 emulator for in-house testing.

C
C++
Python
x86 assembly
PowerPC assembly
OllyDbg
IDA Pro

Purdue Genomics Database Facility, West Lafayette, IN 2004–2006

Student Programmer / Tester

Created a wxWidgets-based GUI for a pre-existing program suite for generational genetic recombination simulation using Markov chains. Administered Purdue’s local mirror of the Protein Kinase Resource, including extending its functionality to support user profiles.

C
C++
Java
Python
Perl
Ruby
Bash
Java JNI
Struts
Hibernate
Ant
Apache Tomcat
Ruby on Rails

Guidant Corporation, St. Paul, MN (now part of Boston Scientific) summer of 2005

Programmer, UI Designer

Wrote a wxPython-based application to provide an intuitive graphical interface for writing requirements-testing procedures for Guidant’s programmer-reader-monitor device, which is used to communicate with their heart device line. Wrote a web service which analyzes the testing logs and reports on which tests are running into the most trouble.

Python
SQLite
wxPython
SAX
XSLT

Patents

US-20130321267-A1 “Dynamically Changing a Character Associated with a Key of a Keyboard”
US-20130332822-A1 “Multi-Word Autocorrection”
US-20150347379-A1 “Device, Method, and Graphical User Interface for a Predictive Keyboard”
US-20150347383-A1 “Text Prediction Using Combined Word N-Gram and Unigram Language Models”
US-20200356248-A1 “Systems and Methods for Providing Continuous-Path and Delete Key Gestures at a Touch-Sensitive Keyboard”

Education

Letterform Archive, San Francisco, CA 2024

Completed Type West, an in-person postgraduate certificate program in type design taught by Maria Doreuli, Chris McDonald, Grendl Löfkvist, Kel Troughton, Christopher Slye, and Miguel Sousa. Designed the revival Reckonly and the original type family Chough.

ILT Academy 2022

Completed the online course “Introduction to Latin Type Design” taught by Malou Verlomme. Designed the original type family Gnawbone.

Rensselaer Polytechnic Institute, Troy, NY 2006–2008

Masters in Computer Science

3.33 GPA (cumulative), teaching experience
Topics of research: social network analysis, graph clustering algorithms, programming language design
Thesis: “Timestamp-Based Correlation Measures for Finding Hidden Groups in Chat Rooms”
Member, Upsilon Pi Epsilon (organized biannual programming competition)

Purdue University, West Lafayette, IN 2002–2006

Bachelor of Science with Honors in Computer Science & Mathematics

3.87 GPA (cumulative), Dean’s List
Member, Phi Beta Kappa, Juggling Club, Math Club

Side Gigs

DJ 2017–present

Electronic music DJ (stage name: Treedub) performing primarily with the Ambient Mafia DJ collective. Frequent performer and stage manager on the Ambient Mafia’s weekly Sunday Sundowns show on Twitch, with more than 160 shows recorded and published on Mixcloud. Coordinated and promoted electronic music events and designed event flyers. Performed at Asiento, DNA Lounge, Hawthorn, Space 550, Duende, and various private parties in the Bay Area.

Choral singer 2016–present

Singer for several choirs in the Bay Area, including the International Orange Chorale of San Francisco (IOCSF) 2021–present, LALÒ 2025–present, The Choral Project 2017–2021, and Masterworks Chorale 2016–2017. Bass section leader and concert program designer for IOCSF. Sang in church services at the Congregational Church of San Mateo, the Congregational Church of Sunnyvale, St. Dominic’s Catholic Church in San Francisco, St. Robert’s Catholic Church in San Bruno, and Willow Glen United Methodist Church.

Type designer 2022–present

Participated in Fontober, a challenge to draw a new font or expand an existing one every day during the month of October, in 2023 and 2024.

In collaboration with Looking Up Arts, wrote software to convert the outlines of the letters in the “NO DANCING” sign from cubic splines to biarcs and generate an engineering spec sheet. This allowed the project team to fabricate the 12-foot-tall letters out of steel tubing using a manual pipe bender.

Glyphs
Pixelmator Pro
Python
ReportLab
fontTools

Recording engineer 2020–2021

Podcast recording engineer for No Baton Needed, a podcast hosted by Daniel Hughes featuring interviews with choral conductors and composers including Stephen Schwartz, Jake Runestad, María Guinand, and Charlene Archibeque. Educated remote interview subjects on proper technique for capturing a high-quality interview recording. Edited, mixed, and mastered recordings and music into the final published podcast.

Theatrical sound engineer 2018–2020

Sound engineer or sound designer on the following Bay Area musical theatre productions:

Once Upon a Mattress, West Valley Light Opera (WVLO) 2020
She Loves Me, South Bay Musical Theatre (SBMT)2020
Urinetown, Sunnyvale Community Players (SCP) 2019
A Gentleman’s Guide to Love and Murder, SBMT 2019
Thoroughly Modern Millie, SBMT 2019
Big River, SBMT 2019
42nd St., WVLO 2018
Mame, SBMT 2018
Spamalot, WVLO 2018
The Full Monty, Hillbarn Theatre 2018
La Cage aux Folles, SCP 2018

Designed sound effects, wrote sound scripts for line-by-line mixing, designed sound reinforcement for the actors and pit orchestra, educated actors on proper mic technique and placement, recorded pre-show announcements, mixed the show’s audio live, and diagnosed and fixed sound issues during the show. Wrote a custom markup language for assigning mics to faders in the sound script’s text so that the scenes programmed into the mixing console stay in sync with the sound script read by the operator.

Competitive programmer 2010–2020

Participated in Google Code Jam in 2010 (advancing to round 2), 2016 (round 3), 2017 (round 3), 2018 (round 2), 2019 (round 3), and 2020 (round 2). All solutions were written in Python.

Python

Event planner 2015–2017

Lead organizer for the San Francisco running of the DASH multi-city puzzle hunt in 2015 (DASH 7) and 2016 (DASH 8). Worldwide lead for DASH 9 in 2017. Recruited and organized event volunteers, scouted and mapped the hunt route, coordinated the story author and puzzle design team and city leads, wrote and tested puzzles, managed the event budget, permits, insurance, promotion, printing, and software stack.

Public speaker 2011–2017

Public speaker and member of Toastmasters International. Served the Macintalkers club as Sergeant-at-Arms, Secretary, VP Membership, VP Education, and President, as well as earning ACS and ALB awards. Organized the schedule for club meetings, liaised with the meeting venue, and led meetings and speech contests.