Joanna Chia
Alameda,CA
Summary
Senior-level SWE that is passionate about moving fast and delivering impactful projects that are scalable and reliable. Looking to grow my career into Engineering Management.
Overview
8
8
years of professional experience
Work History
Senior Software Engineer
Brex
San Francisco, CA
06.2020 - 01.2024
- Lead the migration of several legacy services for core product features including Disputes Management, Fraud Alerting, Account Offboarding on the Risk/Fraud Engineering team. Owning the whole process from planning, producing a design, collaborating with cross-functional stakeholders, developing, documenting, testing, and shipping. These projects prevented over a modest estimate of 10M in Fraud Losses per year.
- Maintained and scaled Operation's tooling, building dashboards and workflows to interact with Fraud Levers via Retool. Directly communicated with Operations stakeholders, gathered requirements, and executed for an Ops team that grew from 5 in house to a 100 outsourced team.
- Contributed to building teams by being an active interviewer (performing over 200 interviews in my tenure), mentoring greener team members, and organizing fun team activities to build camaraderie over a remote environment.
Senior Software Engineer
Iterable
San Francisco, CA
07.2017 - 05.2020
- Planned and shipped core features including Product Recommendations, Catalog, Facebook Custom Audience, Message Type Opt-In Subscription Paradigm, and many others with an approximate contract value of $5 million.
- Initiated and led efforts to improve reliability by migrating the Redis client and enabling clustered-mode. Broke out monolith usage of Redis into separate services.
- Mentored junior engineers, elevated the engineering interview experience through new questions and rubrics, and initiated improvements to reduce burnout in the on-call rotation for the team.
- Resolved production incidents as part of the on-call rotation, contributed to playbooks, and troubleshot for specific customers when they were encountering issues. Worked with several components throughout our stack including: Scala on Play Framework, RabbitMQ, ElasticSearch, Postgres, and Redis.
Machine Learning Software Engineer
Workday
San Francisco, CA
09.2015 - 07.2017
- Shipped a Machine Learning Platform based on Spark that handles binary classification on temporal and non-temporal datasets. Including components such as feature extraction, imputation, normalization, grid-search, model selection, and other statistical tools. This tool reduced development time of ML applications from several months to 2-3 weeks.
- Migrated an ML application (that predicts the risk of a worker quitting their job) from its previously ad-hoc codebase to use MP Platform and refined the logic in the model design to more mathematical correctness. This improved the AUCROC score by approximately 4 points on average, and reduced run-time by 70% on average.
- Built a web-service with a RESTful API that managed reading and writing to HDFS, and surfaced unencrypted data to an internal tool that helped gather explicit metrics from our search results.
- Used various tools like Capistrano, Puppet, Ansible, and Docker to maintained Workday's development, testing, staging, and production environment for the Insights and Search teams.
Education
Bachelor of Science - Mathematics of Computation
University of California - Los Angeles
Los Angeles, CA06-2015
Skills
- Kotlin
- Elixir
- Scala
- Functional Programming
- Retool
- API Development
- Postgres
- Kafka
Timeline
Senior Software Engineer
Brex
06.2020 - 01.2024
Senior Software Engineer
Iterable
07.2017 - 05.2020
Machine Learning Software Engineer
Workday
09.2015 - 07.2017
Bachelor of Science - Mathematics of Computation
University of California - Los Angeles