# Crystal Billy > Full Stack Software Engineer | Ex-Meta Location: San Francisco, California, United States Profile: https://flows.cv/crystalbilly Full stack software engineer with 10+ years of experience. Known for bringing lots of energy and fun to work, and building great products of course. ## Work Experience ### Software Engineer @ Tools for Humanity Jan 2026 – Present ### Software Engineer @ Phantom Jan 2023 – Jan 2025 | San Francisco, CA • Led full-stack revamp of the fiat onramp flow, integrating Meld, MoonPay, PayPal, Venmo, Robinhood and more; improved funnel by +3% and contributed to record $134M/month volume. • Added 49-currency support and localized pricing across the app. • Built end-to-end transaction tracking for accurate analytics and unified provider integrations. • Migrated core services to NestJS + Kubernetes, reducing latency from ~4s → 40ms. • Added Mint NFT feature, enabling 356k+ free NFTs minted. • Improved onboarding flows, contributing to 12% onboarding lift. • Added Quest feature, resulting in 500k quests completed and increased engagement. • Integrated AppsFlyer SDK for install/post-install attribution. • Led team in reducing tech debt and improving E2E test reliability (Maestro, Playwright). • Helped with team incidents and ran blameless post-mortems to improve engineering reliability. ### Software Engineer @ Meta Jan 2018 – Jan 2022 Full-stack engineer working on suite of enterprise products to help Meta hire top talent and reach aggressive hiring targets • Worked on 0 -> 1 project to automate interview scheduling companywide, which reduced the need for manual work, freed up recruiting time to focus on candidate experience, and enabled the company to grow from 30,000 to 87,000 employees. • Highlights of my contributions: added functionality to scheduling constraint solver, developed features to improve data quality for automation, developed key backend pieces for autonomous scheduling. • Collaborated with recruiters, coordinators, legal, admins, designers, data scientists, product managers, engineers, and more within the company to understand business problems, come up with solutions, and align on direction. I also drove projects forward, led technical direction, and implemented solutions. • Reduced the size of our org’s database by 40%, which reduced slow replication and significantly sped up eng development org-wide. • Mentored teammates, new hires, and 3 interns. 100% of my interns received return offers! ### Software Engineer @ TapSense Jan 2012 – Jan 2018 TapSense (acquired by Wish) was a mobile marketing platform that connected app developers with brand advertisers. • Migrated a live distributed system to VPC, while maintaining 9 billion requests per day. • Designed a feature that dynamically adjusts bids based on historical performance, which optimized clients' advertising dollars and automated adops team's manual labor. • Created a feature to serve ads with personalized images and localized messaging, which increased advertiser ROI by 3x. Used redis caches to provide necessary user-level data while keeping response time under 10 milliseconds. • Automated a process to convert HTML ads to animated gifs. This made creatives display more reliably, reduced creative size, and decreased dependencies, which provided a better user experience and improved clients' metrics. • Collaborated with external clients, business team, and engineering to plan and execute different projects, including lift tests, user segmentation, A/B testing different ad formats, etc. • Published iOS and Android apps, which allowed users to check the design of ads and look at reports. • Worked on SDKs, adapters, and plugins for Android, iOS, Apple Watch, JavaScript, and Unity. Also wrote documentation and provided technical support to publishers and advertisers. • Designed and implemented the company's dashboard for customers and internal users. Features include reports, debugging tools, and webapps for managing campaigns, advertisers, publishers, bidders, and server settings. • Wrote scripts to monitor uptime of servers, automate deploy processes, verify data consistency, email reports, etc. ## Education ### Lowell High School ### Bachelor of Science (BS) in Computer Science, Double-minoring in Technology Management and Linguistics University of California, Davis ## Contact & Social - LinkedIn: https://linkedin.com/in/crystalbilly --- Source: https://flows.cv/crystalbilly JSON Resume: https://flows.cv/crystalbilly/resume.json Last updated: 2026-04-11