# Tientien（Daphne) Hsieh > Software Engineer Location: Cupertino, California, United States Profile: https://flows.cv/tientiendaphne A biotech professional turned software engineer. Worked 5 years in the bay area biotech sector before making the switch to tech. ## Work Experience ### Senior Software Engineer I - Core infrastructure @ Poshmark Jan 2025 – Present | Redwood City, California, United States Implemented queue worker health checks in Kubernetes, improving reliability and observability of critical background jobs. Designed APIs for newly launched services and established conventions for future adoption, ensuring consistent patterns across teams. Extracted core services from the monolith into standalone EC2 services, improving scalability and maintainability. Benchmarked and standardized Redis client usage (Redisson, Jedis) Migrated from deprecated Trinidad server to Puma, achieving better performance and long-term support after thorough benchmarking. Integrated Google reCAPTCHA Enterprise to strengthen platform security against bots. Standardized application server logging to JSON, streamlining monitoring, debugging, and log analysis in Kubernetes. Built, maintained, and upgraded Ruby gems to standardize libraries, reducing code duplication and improving developer productivity. Implemented YAML linting with GitHub Actions, enforcing syntax/style standards and preventing misconfigurations in CI/CD. ### Software Engineer II - Core infrastructure @ Poshmark Jan 2023 – Jan 2025 | Redwood City, California, United States ### Software Engineer I @ Poshmark Jan 2022 – Jan 2023 ### Site Reliability Engineer @ Clique Brands Jan 2021 – Jan 2022 As a SRE at who what wear, I am responsible for the following: • Set up and maintain kubernetes cluster in EKS; Proficient in AWS services including load balancer, IAM, EC2, VPC, subnets..etc • Dockerized and deployed existing 3 golang applications: main whowhatwear site, internal app for fashion editors, image serving for the main site. • Create CICD workflows (github actions) to integrate and deploy new versions of applications. • Refactor legacy code base in golang with modern software development practices • Maintain nginx ingress controller to restrict/allow ingress traffic, allow certain IPs, while using cloudfare's WAF • Set up grafana/prometheus dashboard to port logs and enable visibility into cluster health, httpreq/sec • Constantly work with the development team to enable seamless integration of new features written in go. • Research new use cases of kubernetes features and best practices to enable a secure and easy operating environment ### Research Associate II @ REVOLUTION Medicines Jan 2018 – Jan 2021 | Redwood City • Utilize Python tkinter, pandas, and openpyxl library to create simple GUI to parse and restructure excel and csv files to streamline high throughput screening data analysis/ compound processing • Set up scripts in laboratory robots such as Bravo and Tecan to minimize manual labor • Developed and optimized cellular and biochemical assays to characterize compound behavior • Utilized cellular and biochemical approaches to characterize compounds to target oncogenic proteins. • Performed experiments in the following techniques: - Cell based assay: MSD, Alphalisa, pull-down ELISA, Cell viability assay - Biochemical and biophysical screening assay including TR-FRET, SPR, and fluorescent readouts - Involved in SPR fragment screen to find potential binding sites for discovery projects - Automation: Agilent Bravo, Mosquito, multidrop - Standard molecular techniques: cloning, western blot, RNA/DNA isolation, qPCR • Review and interpret experimental data, present results at group meetings • Utilize scientific software: Prism ### Research Assistant @ REVOLUTION Medicines Jan 2017 – Jan 2018 | Redwood City, California ### Software Engineering student @ Hackbright Academy Jan 2020 – Jan 2021 | San Francisco Bay Area • Accelerated Software Engineering programing focusing on full-stack web development • Individual Project- Into the Ghibli World - Full-stack single page web app built with Flask/Jinja framework allowing users to see the real world locations that inspire the scenes in Studio Ghibli movies - Built with React components and several APIs including Google Maps Javascript, Google Places, and OpenTripMap to display map and custom markers, and/or fetch location data . - Implemented search bar allowing user input and React hooks to display data based on input data - Utilized SQLAlchemy to manipulate PostgreSQL database in the backend - Data source: data collected from several travel websites, Studio Ghibli API, and IMDB - Designed with Bootstrap and CSS and on AWS with custom domain ### Manufacturing Technician @ Thermo Fisher Scientific Jan 2016 – Jan 2017 | Pleasanton, California • Work in a fast-paced cGMP environment and generate approximately 100 clones per day • Proficient in molecular biology techniques: seamless cloning, restriction enzyme digestions, Gibson cloning, ligase independent and dependent ligation • Worked in project to utilize alternative PCR methods to reduce duration and reach higher cloning efficiency. • Multitask and troubleshoot with supervisors to evaluate options to reduce cost and duration. • Talk in group meetings everyday to update work process and issues ### Undergraduate Research Assistant in Dr. Chiu's lab @ UC Davis Jan 2014 – Jan 2016 | Davis • Worked in projects to generate recombinant protein to create antigens for circadian proteins. • Performed molecular cloning tasks such as Primer Design, PCR, Agarose Gel Electrophoresis, Restriction Enzyme Digestions, DNA Isolation, plasmid purification, cell culture grow and maintenance, E.coli Transformation. • Analyzed DNA sequence through software such as CLC sequence and bioedit. • Proficient in protein work such as checking solubility, microfluidizer, SDS-PAGE gel and coomasie staining. • Assisted Junior specialist with utilizing Next Generation chromatography system with the Nickel resin column and desalting column to purify proteins • Performed RNA extraction, RT-PCR, and qPCR to quantify the circadian genes of migratory and non-migratory butterflies. • Prepared buffers, organized fly stock, autoclaved glasswares and assisted with lab maintenance. ### Undergraduate Assistant in Dr. Ramsy's mice room @ UC Davis Jan 2015 – Jan 2016 | Davis • Assisted lab manager Dianna Tran to take care of 100 mice that are used for longevity experiments. • Tasks include: insured enough diet is made everyday, fed the mice and monitored them to see if they developed dermatitis and other diseases, changed cages and water every two weeks, and assisted in mice dissection when needed. ## Education ### Computer Software Engineering Hackbright Academy ### Bachelor's degree in Biochemistry and Molecular Biology University of California, Davis ### Cupertino High School ## Contact & Social - LinkedIn: https://linkedin.com/in/tientien-daphne-hsieh --- Source: https://flows.cv/tientiendaphne JSON Resume: https://flows.cv/tientiendaphne/resume.json Last updated: 2026-04-01