Karan Joisher
Software Developer, B.Tech in Computer Engineering

I am currently a Senior Software Engineer at Hewlett Packard Enterprise, developing high-performance RDMA library for distributed object storage systems.
My main interests include:
- Software development (Backend systems, microservices, distributed systems, etc.)
- Systems programming (Operating systems, networks, etc.)
- Tools development (Debuggers, graphics, etc.)
My goal is to develop performant, easy-to-use tools that leverage the immense potential offered by modern hardware, making overall computing experience much smoother and bloat free for users and developers.
Other than programming, my hobbies include:
- Sim Racing (mainly on iRacing)
- Go-karting
- Skiing
Education
Northeastern University
M.S. in Computer Science
Boston, MA | Sep 2022 - Apr 2024
GPA: 4/4
Coursework: Operating Systems (Received Rockstar Programmer Award), Program Design Paradigms, Database Management Systems
K.J. Somaiya College of Engineering
B.Tech in Computer Engineering
Mumbai, India | Aug 2015 - May 2019
CGPA: 8.56/10
Coursework: Computer Architecture, Operating Systems, Systems Programming and Compiler Construction, Fundamentals of Programming, Data Structures, Algorithms
Experience
Hewlett Packard Enterprise
Software Engineer 2
Andover, Massachusetts | Jun 2024 - Present
- Built NVGrid, a high-performance C++ RDMA library powering distributed object storage clusters, enabling east-west data transfer rates up to 400 Gb/s.
- Developed observability tooling to capture FlameGraphs, switch packet drops, and network statistics; to help diagnose performance bottlenecks.
- Tuned switch QoS policies, reduced lock contention and thread starvation, and balanced internode vs. disk I/O bandwidth, increasing cluster throughput from 128 Gb/s to 400 Gb/s.
- Replaced VMware ESXi with HPE VM Essentials and SR-IOV, enabling deployment of RDMA-capable Kubernetes clusters for development and testing, saving $3,500 per host annually in licensing costs.
- Developed a Producer–Consumer RDMA protocol to replace a Client–Server model, reducing internode operations per transaction from 4 to 3 and lowering latency by 5%.
- Developed an error injection API over gRPC that injects faults directly into the RDMA device context (CQ, async event queue), allowing validation of error-handling paths rarely triggered under organic workloads.
- Developed NAE scripts for Aruba CX 9300 switches to handle interface split and speed requirements, eliminating manual configuration and enabling factory units to support all HPE storage products.
- Tech used: C/C++, IBVerbs, Boost, gRPC, Redis, Kubernetes, Docker, Grafana, Bazel, GoogleTest, Jenkins
Hewlett Packard Enterprise
Software Engineer Intern
Andover, Massachusetts | May 2023 - Dec 2023
- Developed TCP channel for non-RDMA NICs, and Shared Memory channel for services on the same node
- Engineered Connection Manager library for establishing channel connections between nodes; used gRPC service framework and Redis for service look-up; and Boost state machine for connection orchestration
- Architected Telemetry library to monitor the health and performance metrics of NVGrid components and integrated it with Grafana for visualization
- Tech used: C/C++, IBVerbs, Boost, gRPC, Redis, Kubernetes, Docker, Grafana, Bazel, GoogleTest, Jenkins
Northeastern University
Research Assistant
Boston, Massachusetts | Jan 2023 - May 2023
- Provided SME support for Discovery Cluster on topics ranging from Linux, Slurm, Docker, MPI, Cuda, and Distributed ML Training
- Orchestrated concourse pipelines to build and deploy containers of docker and Singularity
- Collaborated with researchers to construct and launch large ML models on multi-GPU clusters, leveraging PyTorch and TensorFlow
Barclays
Software Developer
Pune, India | Jul 2019 - Jul 2022
● Barclays Mobile Banking APIs
○ Designed and developed an ecosystem of APIs for setting up repayment plans for delinquent accounts.
○ Gained 5x improvement in API response times by making downstream API calls asynchronous and parallel.
○ Implemented a performance logging and monitoring library to track performance of these APIs.
● Customer Outcome Testing Application
○ Gathered requirements from bank agents to understand how they manually reviewed collection cases.
○ Developed a backend API and database components to digitize the manual case review process.
○ Closely worked with bank agents to build UI and iterate over the application flow.
○ Key Achievements: Reduced manual effort for case reviews by 232 hours/week (5.8 FTEs).
● AWS Microservices and Cloud Infrastructure Automation
○ Developed microservices to create collection cases for delinquent accounts received via Apache Kafka events.
○ Created CloudFormation templates to deploy auto-scaling ECS clusters, MSK clusters, RDS, and EC2 machines on the AWS cloud platform.
○ Implemented AWS Lambdas for rotating credentials and replicating EBS volumes to backup data.
○ Developed features for APIs to automatically fetch the latest credentials from AWS Secret Manager.
○ Key Achievements: Single-click infra provisioning; Reduced server costs by demand-based cluster scaling.
Accelo Innovations
Computer Vision Developer
Mumbai, India | Aug 2017 - Oct 2017
- Developed depth mapping module (using stereo-vision) in Python and C using a two camera setup.
- Integrated Tensorflow’s object detection with the depth mapping module to identify objects and calculate their distance from the vehicle.
Truckerrs
Frontend Developer
Mumbai, India | May 2016 - Jun 2016
- Designed the UI/UX for the website.
- Implemented the front-end of the booking system and integrated it with the back-end API.
- Used Google Maps API for features such as tracing the path of the vehicle on map.
TapTheTech
Flash Animator
Mumbai, India | Mar 2013 - Jan 2014
- TapTheTech was a group of students who believed MOOCs are the future of education. It went on to become one of the official learning hubs on Coursera
- I was one of the core team members and created content, animations for the educational videos on the YouTube channel; helped organize events in schools to spread awareness about MOOCs