- Philadelphia, PA 19102
- (601) 594-4973
- [email protected]
- GitHub
- Personal Website
- 2009 - 2014: BA-Biochem & Art, Belhaven University
- 2014 - 2016: Pathology PhD, UMMC (dropped out)
- 2016 - 2018: Computer Science, Mississippi State
- Fullstack
- Backend
- DevOps
- Cloud, AWS
- SRE
- System Design
As a Software Engineer, I excel in languages like JavaScript, TypeScript, Golang, and Python, with a solid background in full-stack development and cloud technologies. My career highlights include Sr Software Engineer at PNC, Ally, and Finance of America, developing key backend systems and integrating multifaceted applications through serverless cloud or microservices. Beyond technical prowess, I'm passionate about mentoring and community engagement, leveraging technology for societal benefit. I'm dedicated to crafting innovative software solutions that align with both business needs and social good.
Sr Software Engineer
- Contributed to a fullstack React Typescript and NodeJS POC application for PNC customers managing their 3rd party services subscription and transaction.
- Worked on building PNC's brand new internal underwriter application for management and handling loan origination and underwriting tasks with flowable workflow service.
- Started and worked on multiple Java Springboot microservices, and a micro frontend driver and portal UI applications in Angular.
- Responsible for performance testing and release management.
- Monitor and maintain Jenkin pipelines, K8S template deployed through Openshift.
Sr Software Engineer
- Led the development of the credit card serverless backend API with AWS and delivered on time before launch.
- Created a Serverless self heal system to automatically retry failed messages with Golang, lambda, and SQS, eliminating 70% of manual work.
- Built a fullstack portal application with React and NodeJS to assist enterprise data steward team processing and handling data with role-based permission.
- Helped build a Kafka producer for relaying system messages to ALLY Enterprise Kafka cluster in Java Spring.
- Security Champion: Completed level 2 security training and worked as a security agent safeguarding project code quality and scans, triaging any security vulnerability before production release.
- Created a Splunk and Datadog dashboard for project observability.
- Technologies: NodeJS, Golang, Python, Java, Spring, AWS AppSync, StepFunctions, Lambda, SQS, SNS, DynamoDB, DynamoDB Stream, EventBridge, ECS, CloudFront, Glue, Okta, Kafka, Terraform, Serverless, Splunk, Datadog, React Typescript.
Sr Software Engineer
- Developed full-stack applications for the homeshare project, Silvernest.
- Responsible for building new features for both frontend and backend using Next.js, React, Redux, NodeJS, PostgreSQL, Kibana, AWS, and Azure DevOps.
- Integrated third-party services like Stripe, Intercom, and Plaid.
- Maintained the database, Kibana, and Elasticsearch.
Fullstack Engineer
- Built internal applications for frontend and backend using React, Redux, ImmutableJS, GraphQL, NodeJS, MongoDB, and MySQL.
- Implemented Concourse pipelines for deployment.
Minna Transaction and Subscription APP (POC Fullstack APP)
- This POC is a fullstack application that aims to enable PNC customers to manage and handle their subscriptions to 3rd party services like Netflix, Disney, or Spotify, and relevant transactions on their credit cards. Built with React Typescript and NodeJS as backend. Uses Tailwind for styling.
PNC Internal Dashboard App (Internal Application)
- This is one of the new applications for PNC underwriters to manage internal lending functionalities and loan origination. Built with Angular JS with Microfrontend framework and uses Java Springboot for backend. It employs flowable workflow for handling many of bank's lending workflows, such as fraud management, interacting with FICO, Experian, etc. Responsible for building both frontend and 3 different microservices. CICD is Jenkins and it is deployed to K8s through Openshift.
Credit Card Core API (Serverless Application)
- Lead engineer building out this API for ALLY's new lending credit card product. It works with 3rd party vendor Provenir, and accepts credit card applications and processes them, then relates them to downstream enterprise services for further processing and final decision. Built on AWS, with AppSync GraphQL, DynamoDB stream resolvers, Lambda, SQS, and Step Function. Provisioned and architected the entire project with Terraform, and also set up Splunk, and Datadog for SRE.
Kafka Producer and Consumer API (AWS ECS and API Gateway)
- Built the producer and consumer using Java Sprint and Maven, they are RESTful APIs for sending and receiving messages to and from the Enterprise Kafka cluster for further processing or alert in many downstream business SOR. These APIs were deployed to AWS ECS through Gitlab CICD and resources were provisioned with Terraform.
Self Heal System (AWS, Terraform, Golang)
- Serverless application for automatically polling failed messages from DLQ across all projects in our team, and redrive them. Written in Go with AWS Lambda, using concurrency to process messages across all queues in parallel. Deployed to AWS through Gitlab CICD and provisioned with Terraform.
Batch Files Processing Service (Serverless Application, AWS Lambda, ECS, and Golang)
- Designed to handle the ingestion and processing of CSV files uploaded by various teams to an S3 bucket daily. Processing workload managed by an ECS Fargate cluster. Developed a custom Golang service for parallel processing to enhance efficiency, transforming records before enqueuing them into a FIFO queue.
Internal Portal (Fullstack Application, React, NodeJS)
- Designed for teams accessing customer data or managing configuration for different credit card services with role-based security. Frontend built with React Typescript, backend with NodeJS on AWS Lambda and API gateway. Managed through Gitlab CICD and provisioned with Terraform.
Distributed Real-Time Data Processing System (AWS ECS, S3, and Golang)
- Engineered a scalable and fault-tolerant distributed system in Go, capable of ingesting and processing large data volumes from various sources in real-time. Implemented a high-throughput data ingestion service, a distributed processing engine with Kafka for horizontal scalability, a dynamic load balancer for optimal resource utilization, and a real-time analytics dashboard. Enhanced system resilience and efficiency through advanced fault tolerance, backpressure management.
Unified Platform Application (SingleSPA with React Typescript, and NestJS)
- Part-time project, featuring a unified platform application consisting of many React Typescript micro frontend applications through SingleSPA. Responsible for building the dashboard micro frontend, and part of the management API with NestJS.
Phone Registry Scraping App (Python, ECS, Selenium)
- Commissioned by Verizon to scrape telephone registries and other business info on Google. Written in Python, using Selenium deployed to AWS ECS. Includes script handling Google detection and automatically rotating Proxies to avoid being blocked by Google. Data processed and transformed by another Python service, stored in CSV for delivery to client.
Common Style Components (React, Tailwind, Storybook, NPM)
- Contains all the styling components of the team. Built with React Typescript, Tailwind, and Storybook for local development. Deployed to private NPM registry for team projects.
Silvernest Homeshare (Fullstack React Typescript, NodeJS, and AWS)
- Monolith fullstack application designed for seniors to share their homes similar to Airbnb. Built with React Typescript and Material UI for frontend, and NodeJS and Express for backend, using PostgreSQL for the database.
Internal Dashboard Application (Fullstack React, NodeJS, GraphQL, MongoDB)
- Internal dashboard project consisting of many API services, and a React frontend. Responsible for building new frontend features with React, GraphQL for frontend, and used NodeJS, GraphQL, and MongoDB for backend.
- 2023 - Present: Lead Team Mentor, Develop For Good
- 2023 - Present: Translator, HIAS Philadelphia
- 2023 - Present: Web Developer, Liberia Medical Mission
- 2021 - Present: Lead Instructor, Pluralsight
- 2023 - Present: Lead Instructor, Fullstack Academy
- 2022 - Present: Lead Instructor, ThriveDX
LLM API Agent (NPM package)
- NodeJS package designed to interpret human language prompts and determine the appropriate API endpoint based on a configuration file. Simplifies the process of sending requests and processing responses from human language inputs.
- [
GitHub](https://github.com/dsl2022/IIm-api-agent)
AI Chat Interface (NextJs, Typescript, frontend)
- Simple chatbot UI interface, designed as a starter app that can be integrated into any project. Works with a RESTful API with SSE, sending real-time updates from API to UI.
- GitHub
- Demo
AI Chat Interface Restful Backend (Typescript, NodeJS, Express, Docker, OpenAI)
- Utilizes Server-Sent Events (SSE) to enable real-time communication between the server and clients. Built with NodeJS and can be containerized using Docker.
- GitHub
MOMO - a Twitter Poem & Images Robot (AWS, Terraform, Python, OpenAI)
- AI by Terraformia, crafts thrice-daily poems and visuals using OpenAI and DALL-E, with Python and Terraform for seamless deployment.
- GitHub
###2021 - 2022
Liberia Medical Mission (Fullstack, React, AWS, GraphQL, NodeJS)
Silvernest (NextJs, Typescript, fullstack, React, Angular)
- Home share project for Finance Of America. Contributed 60% of the code.
- Silvernest
istio-control-pane - a teaching project (ISTIO, K8S, Linux, AWS)
- Demo teaching project for the Pluralsight enterprise training course. Uses ISTIO as a sidecar to control traffic, achieving scalability and network traffic capacity and throughput control. Deployed to AWS with KOP, a tool for provisioning K8s clusters.
- GitHub
- Piano
- Painting
- Cooking
- Jan 4th, 2023: Uploading a Photo to an S3 Bucket with the AWS SDK and React
- 2022-2023: Memoization in Golang
- Jan 1, 2023: Understanding Inheritance in Python, JavaScript, and Go
- Dec 27, 2022: Become a Golang Pro with These 10 “Defer” Trick
- Oct 2, 2021: Javascript Gotcha — forEach loop
- Apr 11, 2021: S3 upload with presigned URL — React and NodeJS
- Mar 23, 2021: How to Promisify a Callback and Resolve its Returned Data
To Whom It May Concern,
Dear Hiring Manager,
I am writing to express my interest in the software engineer position at your company, as advertised. With a strong foundation in software engineering and a proven track record of success in full-stack development and cloud technologies, I am excited about the opportunity to contribute to your team.
I am currently working at PNC bank as a Sr Dev, where I have successfully picked up JAVA and Angular. With my prior development experience, I quickly adapted to everything that was totally new to me here. Now, I am taking a lot of responsibility, including API and UI development, deployment maintenance and debugging, working with the lead developer to improve the CICD pipeline, as well as exploring new functionalities or POC opportunities.
During my tenure at Ally, I led the development of a significant backend system for a credit card service, showcasing my ability to manage complex, high-stakes projects effectively. This role required deep technical knowledge, innovation, and a collaborative mindset, all of which I leveraged to achieve successful outcomes. At Finance of America, I further honed my skills in full-stack application development, integrating various third-party services and maintaining robust database systems.
My technical expertise is broad, encompassing multiple programming languages such as JavaScript, TypeScript, Golang, Python, and Java. I am particularly adept at cloud-based solutions using AWS and experienced in DevOps practices, which enable me to streamline development processes and enhance productivity.
Beyond my technical abilities, I am passionate about teaching and mentoring. My experience as an instructor at institutions like Pluralsight and FullStack Academy has not only reinforced my technical skills but has also refined my abilities in communication and leadership.
Thank you for considering my application. I look forward to the opportunity to discuss how my skills and experiences align with the needs of your team. I am available at your earliest convenience for an interview.
Warm regards,
David J Liang