Bibek Bhusal, Senior Software Developer in Seattle, WA, United States
Bibek Bhusal

Senior Software Developer in Seattle, WA, United States

Member since February 1, 2021
Bibek is a senior software developer with 10+ years of experience building large-scale distributed applications. He has worked at Amazon for eight years, where he developed critical systems for Retail, Alexa, and logistics businesses. He co-authored the design of a highly scalable balance tracking system capable of processing 40,000+ transactions per second that increased throughput by 5x and reduced operating costs by 3x. Bibek is a goal-oriented and experienced tech lead across timezones.
Bibek is now available for hire

Portfolio

  • Amazon.com
    Software Architecture, Distributed Systems, AWS, Amazon Machine Learning...
  • Amazon.com
    Distributed Systems, AWS, Java, REST, Agile, Software Architecture...
  • Amazon.com
    Java, Spring, Hibernate, JSP, SFTP, Workflows

Experience

Location

Seattle, WA, United States

Availability

Part-time

Preferred Environment

Java, AWS, Linux, Git, MacOS, IntelliJ IDEA

The most amazing...

...application I've built is Amazon Cash. It allows Amazon customers to add cash to their Amazon Balance in real-time from retail stores such as CVS and Walgreens.

Employment

  • Senior Software Developer

    2018 - 2021
    Amazon.com
    • Designed and led the team of seven developers to implement changes in the Amazon Retail pipeline to accept Health Benefit Cards (HSA and FSA) in the US marketplace. The program enabled millions of customers to use their Health Benefit Cards in Amazon.
    • Co-led the design and implementation of changes in the Amazon Retail pipeline to accept EBT cards in the US marketplace. The program was a huge success in the pandemic where millions of low income households were able to use their EBT cards on Amazon.
    • Led the design and implementation of an orchestration system to automate machine learning models training and inference. Built on top of an AWS infrastructure, the system is capable of training thousands of models at a time.
    • Led the redesign of the Alexa Music back-end system from a monolithic service to service-oriented architecture-based services. The design allowed critical APIs to scale independently and reduced development and maintenance costs.
    • Refactored a payment-critical service in the Amazon Retail pipeline to improve its throughput. Reduced from 500+ hosts to just 30 hosts to process 20,000+ transactions per second. Saved thousands of dollars annually in operating costs.
    • Led the design and implementation of a machine learning model repository. Built a multi-tenant application to allow teams across the organization to import their models and track deployment status.
    • Oversaw multiple teams at Amazon building paying experience across Amazon marketplaces. Provided them design guidance and reviewed their architectural design to ensure a simple, secure, accessible, and uniform paying experience.
    • Mentored engineers from different organizations and regularly held knowledge-sharing sessions to share knowledge across organizations.
    Technologies: Software Architecture, Distributed Systems, AWS, Amazon Machine Learning, Cloud Computing, Spring, REST, Java, AWS Step Functions, AWS Lambda, AWS Batch, AWS Fargate, AWS CloudFormation, Amazon SQS, AWS DynamoDB, AWS Push Notification Service (AWS SNS), ECS, Docker, Amazon SageMaker, Python, AWS S3, AWS API Gateway, Git, Architecture, Design Patterns, APIs
  • Software Developer

    2013 - 2018
    Amazon.com
    • Designed and led a group of eight engineers to implement Amazon Cash, an application for Amazon customers to add cash to their Amazon Balance in real-time from retail stores such as Walgreens and CVS.
    • Co-authored the design of a highly scalable balance tracking system, which is built on top of AWS DynamoDB, capable of processing 40,000+ transactions per second. The new system increased throughput by 5x and reduced operating costs by 3x.
    • Led the migration of the Amazon Gift Certificates balance system from a legacy to the new balance tracking system without downtime. Migrated hundreds of millions of customer accounts and billions of transactions to the new system.
    • Led the multi-year effort of automating Amazon Gift Certificates accounting workflows that were responsible for booking billions of dollars of annual revenue. Collaborated with 10+ teams worldwide.
    • Developed a workflow to automatically replace failed activation gift cards. The workflow significantly reduced customer contact and saved more than $10,000+ per month.
    • Served as subject matter expert on multiple services in Amazon Gift Certificates' ordering, fulfillment, balance tracking, and accounting systems. Helped onboard multiple developers to the team and hosted knowledge-sharing sessions for new hires.
    Technologies: Distributed Systems, AWS, Java, REST, Agile, Software Architecture, Team Mentoring, Spring, AWS DynamoDB, Amazon SQS, AWS Push Notification Service (AWS SNS), Hibernate, Automation, Git, Design Patterns, Architecture, APIs, Databases, Microservices, SQL
  • Software Developer Intern

    2012 - 2012
    Amazon.com
    • Designed and implemented a workflow to automate Amazon Gift Certificates code generation and secure upload to third-party printers for printing gift cards.
    • Updated the internal web tool to simplify managing gift certificate code generation workflows and updating third-party printer encryption keys.
    • Integrated LDAP-based authentication to manage access to the gift certificate code generation page in the internal web tool.
    • Launched all of my intern projects two weeks before the deadline and received a returning full-time offer.
    Technologies: Java, Spring, Hibernate, JSP, SFTP, Workflows
  • Software Developer Intern

    2012 - 2012
    FamilySearch International
    • Designed and implemented a RESTful web service to import and persist genealogy data from CSV files with millions of records into a MySQL database.
    • Designed and implemented a paginated web UI to display genealogy data from the web service.
    • Collaborated with senior developers in the team to prepare weekly status reports and to showcase my works in bi-weekly product demo meetings.
    Technologies: Java, Spring, Hibernate, MySQL, Web Services, REST
  • Software Developer Intern

    2010 - 2010
    Brigham Young University
    • Designed and implemented an Android application for university students to automatically log into the secured Wi-Fi provided by the university.
    • Collaborated with other interning students on project design discussions and reviews.
    • Assisted a program manager to come up with the project status to report to senior leadership.
    Technologies: Android, Java

Experience

  • Amazon Cash
    https://www.amazon.com/b?ie=UTF8&node=14583169011

    Amazon Cash is an application that allows Amazon customers to add cash to their Amazon Balance. A customer is assigned a unique barcode that he/she can take to participating retail stores to add cash. The customer's account is credited in retail time, and the customer can use their balance to purchase millions of items at Amazon.

    I was the lead developer of the project. I designed the client-facing APIs and internal systems to process transactions from retail stores. I also led a group of eight engineers to develop the APIs and internal systems. I implemented a few critical APIs, such as credit and refund of balance to/from customers account, and service to notify customers when their account is successfully credited. I designed the barcode generation and validation algorithm.

    I was responsible for creating the API specification and integration document for clients. I led the technical discussions with partners to onboard the APIs to their system. I was a point of contact during their integration and testing. I also led the product beta testing and visited retail stores in a few states to test the product.

    Project launch media reference: https://money.cnn.com/2017/04/03/technology/amazon-cash/index.html

  • SNAP Program Acceptance at Amazon
    https://www.amazon.com/snap-ebt/b?ie=UTF8&node=19097785011

    SNAP is a federal assistance program for eligible low-income individuals and families to purchase certain foods in authorized stores. SNAP funds can be accessed through an EBT card. Historically, EBT cards were only supported at physical retail stores, but in 2017, Amazon got approval to pilot the SNAP program, and my team was responsible for the development work.

    I co-led the design of changes required in Amazon Ordering and Fulfillment pipelines to support EBT cards and led a group of seven engineers across three teams to implement the changes. I was also responsible for updating the payment execution engine, a system that processes all payment transactions in Amazon, to support a product-restricted payment method. My work laid the foundation to support other product-restricted payment methods globally, such as Health Benefit Cards in the US, Product and Food Vouchers in the US and Mexico, and so on.

    SNAP program has become an enormous success enabling millions of low-income customers in the US to purchase foods online via Amazon Fresh and Whole Foods during the pandemic.

  • Highly Scalable Balance Tracking System

    As an engineer in the Amazon Gift Certificates team, I co-led the design of a highly scalable balance tracking system backed by AWS DynamoDB and a NoSQL database to replace a legacy balance tracking system backed by a relational database. The legacy system had performance issues due to its database, which was becoming a scaling bottleneck.

    I led refactoring of the Gift Certificates services to migrate them off the legacy system to the new system. As a part of this effort, I designed and implemented a validation framework to prevent the processing of migrated account transactions on the legacy system. I also implemented a continuous migration strategy that migrated a small set of randomly selected customers to the new system every day.

    In the final phase of the project, I co-led an effort to migrate millions of customer accounts and their transactions from the legacy system to the new system. I co-authored a library that atomically migrated a customer account and corresponding transactions to the new system. We successfully migrated hundreds of millions of customers globally without any downtime.

  • Machine Learning Model Training and Inference Workflow Engine

    As a senior engineer in the Geo-sciences and Maps team at Amazon logistics, I was responsible for designing and implementing an orchestration framework to automate model training and inference. I used AWS Step Functions as a workflow engine and AWS Lambda to proxy a job in each workflow step. For the actual computation in each job, I used AWS Batch and AWS SageMaker. The framework also provided plugins to extract training and inference data directly from Amazon S3 and Glue. I also developed an internal tool to create and publish workflow definitions in AWS Step Functions.

    The framework laid the groundwork for developing multiple machine learning models. The framework supported multi-tenancy and could be used to run workflows in multiple AWS accounts.

Skills

  • Languages

    Java, JavaScript, SQL, Python
  • Storage

    AWS DynamoDB, AWS S3, Databases, MySQL, Redis
  • Other

    AWS, Distributed Systems, Web Applications, Algorithms, Web Services, Software Architecture, Team Mentoring, Technical Leadership, AWS API Gateway, Architecture, APIs, Amazon Machine Learning, Data Migration, ECS, SFTP, Workflows
  • Frameworks

    Spring, Hibernate, Flutter
  • Libraries/APIs

    Node.js
  • Tools

    Git, AWS Step Functions, AWS Push Notification Service (AWS SNS), Amazon SQS, AWS Fargate, IntelliJ IDEA, AWS Batch, Amazon SageMaker, AWS IAM, AWS SES, AWS CloudFormation
  • Paradigms

    REST, Agile, Microservices, Design Patterns, Automation
  • Platforms

    Linux, Software Design Patterns, AWS Lambda, MacOS, Android, Docker
  • Industry Expertise

    Project Management

Education

  • Bachelor's Degree in Computer Science
    2008 - 2012
    Brigham Young University - Provo, Utah, USA

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