Cloud Infrastructure Stack Engineer

HARSIMRAN SINGH

***North Dearborn St, Chicago ● Illinois ● 716-***-**** ● *************@*****.***

Hands-On Technologist Specializing in Mobile Platforms, Cloud Infrastructure, LLM Pipelines, and System Architecture

Professional Summary:

● Technically proficient Full Stack Engineer with 10+ years of experience architecting and delivering complex solutions across mobile platforms, cloud infrastructure, LLM-powered services, and distributed systems.

● Specialized in developing high-performance cross-platform mobile apps using React Native, Kotlin, Swift, Flutter, and native Android/iOS SDKs. Extensive expertise in UI/UX design, accessibility (WCAG 2.1), and CI/CD automation using Bitrise and Fastlane.

● Deep experience building cloud-native applications and microservices on AWS

(Lambda, EKS, API Gateway, DynamoDB), GCP, and Azure with Node.js, Spring Boot, and FastAPI, leveraging Terraform, Helm, and Docker for deployment automation.

● Architected LLM pipelines and agentic AI workflows using LangChain, HuggingFace, OpenAI APIs, and vector databases like Pinecone, Redis, and Weaviate, integrated into production systems with FastAPI, Celery, and LangGraph orchestration.

● Strong command of DevOps, SRE, and Infrastructure-as-Code principles; implemented ArgoCD, GitHub Actions, and OpenShift GitOps to manage secure, multi-tenant Kubernetes workloads across regulated environments.

● Experienced in real-time streaming systems using Apache Kafka, WebSockets, and gRPC, building scalable, event-driven backends that power visualization dashboards and mobile APIs.

● Integrated enterprise-grade authentication and authorization workflows using Keycloak, OAuth2, OIDC, and JWT-based access controls, across both B2B and internal platform use cases.

● Demonstrated ability to lead initiatives in LLM agent engineering, blockchain- integrated apps (Ethereum, IPFS), and robotics automation (ROS2, Gazebo, YOLOv8).

● Passionate about AI-driven development workflows, edge intelligence, and secure- by-design systems. Recognized for driving cross-functional collaboration, accelerating delivery pipelines, and scaling intelligent systems from prototype to production.

Technical Skills:

Mobile Development: React Native (Expo, Bare Workflow), Flutter, Kotlin (Jetpack Compose), Swift (SwiftUI), Android SDK, AVD, SQLite, Firebase, Bitrise, Fastlane, BLE, WCAG 2.1 Accessibility

Frontend Development: React.js, Next.js, Redux, JavaScript (ES6+), TypeScript, HTML5, CSS3, Tailwind CSS, SASS, Bootstrap, Webpack, Module Federation, ECharts, Mapbox Backend Development: Node.js, Express.js, Spring Boot, FastAPI, GraphQL, REST APIs, WebSockets, gRPC, Kafka, SNS, SQS, AWS Lambda, Celery, JWT, OAuth2, Keycloak AI & LLM Integration: LangChain, HuggingFace Transformers, OpenAI APIs, Pinecone, Redis, FAISS, LangGraph, Prompt Engineering, Agentic Workflows DevOps & Infrastructure: Docker, Kubernetes (EKS, GKE), Helm, ArgoCD, GitHub Actions, OpenShift GitOps, Terraform, Tekton, Snyk, Trivy, CI/CD Pipelines, Infrastructure as Code (IaC)

Cloud Platforms: AWS (Lambda, DynamoDB, S3, SNS, SQS, CloudFront, API Gateway, IAM), GCP (Cloud Run, Firebase), Azure DevOps

Databases & Storage: PostgreSQL, MongoDB, DynamoDB, Redis, MySQL, Oracle, IPFS Testing & Quality Assurance: Jest, Mocha, Chai, Enzyme, Detox, Cypress, TDD, BDD, Unit Testing, Integration Testing, End-to-End Testing Programming Languages: Java, Kotlin, Swift, Python, TypeScript, JavaScript (ES6+), Go

(basic), Bash

Version Control & Collaboration: Git, GitHub, GitLab, Bitbucket, Perforce, Jira, Confluence, Slack Integrations

Security & Authentication: Keycloak, OAuth2, OIDC, JWT, HTTPS, End-to-End Encryption (E2EE), RBAC, IAM Policies

Design & Prototyping Tools: Figma, Adobe XD, Sketch, Indigo Studio, WireframeSketcher, FluidUI

Operating Systems: Linux, macOS, Android, iOS, Windows Professional Experience:

ContexIQ, IL March’25 – Current

Principal Architect / Founding Engineer (LLM Systems & Agentic AI)

● Spearheaded the technical architecture and implementation of an enterprise-grade agentic AI platform designed to deliver scalable, domain-specific solutions using large language models (LLMs).

● Led the development of modular agent frameworks with dynamic tool use, contextual memory recall, and autonomous reasoning using LangChain, LangGraph, HuggingFace, and OpenAI APIs.

● Architected Retrieval-Augmented Generation (RAG) pipelines integrating Pinecone, Redis, and FAISS for performant vector search and domain-specific document retrieval.

● Leveraged AWS Lambda to create stateless microservices that handle agent decision-making logic, prompt routing, and tool orchestration on-demand.

● Used AWS SQS and SNS to decouple agent workflows, manage retry policies, and deliver asynchronous execution of background tasks like document ingestion, summary generation, and audit logging.

● Integrated DynamoDB for storing agent memory snapshots, user session state, and configurable toolchain templates—supporting multi-tenant isolation and high- throughput reads/writes.

● Built infrastructure for agent lifecycle management, prompt evaluation, and automated agent testing with support for A/B evaluations and continuous delivery.

● Established a secure, scalable backend architecture using FastAPI, Kubernetes

(EKS), and Docker, with infrastructure-as-code via Terraform and deployment automation through ArgoCD and GitHub Actions.

● Directed CI/CD pipelines and implemented observability tools to monitor agent performance, debug token traces, and log key decision metrics.

● Collaborated with product, design, and research stakeholders to turn high-level platform vision into APIs, SDKs, and developer-facing services.

● Owned architectural decisions around memory strategies, plugin chaining, protocol design, and horizontal scaling of multi-agent systems. Environment: Python, FastAPI, AWS (Lambda, DynamoDB, SQS, SNS, EKS), OpenAI APIs, LangChain, LangGraph, HuggingFace, Pinecone, Redis, Docker, Kubernetes, Terraform, ArgoCD, GitHub Actions

National Geospatial Agency (NGA), Remote September’23 – March’25 Senior Full Stack Developer / Platform Engineer

● Developed interactive, real-time dashboards for defense operations using React.js, D3.js, and WebSockets to visualize geospatial intelligence.

● Engineered API-driven backend services in Node.js, supporting secure data transformation and delivery of high-volume streams from satellite feeds and IoT devices.

● Integrated AWS S3 for secure storage of satellite snapshots and metadata; built Lambda-based services for on-the-fly image transformation and classification.

● Used PostgreSQL with PostGIS extensions for spatial queries; designed caching layers using S3 and CDN to accelerate frontend performance.

● Built event-driven pipelines with Kafka, SNS, and SQS, enabling distributed data processing and alerting based on custom geospatial triggers.

● Implemented RBAC, audit trails, and encryption using Keycloak and secure AWS IAM roles; ensured compliance with federal security standards.

● Containerized services using Docker, deployed microservices to hardened Kubernetes clusters via ArgoCD and OpenShift GitOps, and enforced CI/CD policies with Tekton.

● Mentored engineers on DevSecOps best practices, geospatial API design, and cloud-native engineering patterns.

Environment: AWS (S3, Lambda, SNS/SQS), Node.js, React.js, TypeScript, D3.js, PostgreSQL/PostGIS, Kafka, Docker, Kubernetes, ArgoCD, OpenShift, Keycloak USAR, KS,IL March’16 – November’24

91B Wheeled Vehicle Mechanic (Enlisted Specialist)

● Served 8 years in the U.S. Army Reserve with distinction; awarded the Commander’s Medal for graduating top of class at Advanced Individual Training (AIT).

● Selected for Officer Candidate School (OCS) based on leadership potential, discipline, and demonstrated technical excellence.

● Conducted complex diagnostics, repair, and preventative maintenance on mission- critical military vehicle fleets under time-sensitive and high-stress conditions.

● Applied systematic troubleshooting, root cause analysis, and documentation practices

— skills that translate directly to debugging and production support in tech environments.

● Led junior personnel in operations readiness, equipment audits, and team-based mechanical projects, fostering a mission-first and collaborative approach.

● Demonstrated operational discipline, resilience, and adaptability — foundational traits in agile development, DevOps, and cross-functional team environments. Environment: Technical troubleshooting, systems diagnostics, team leadership, logistics coordination, SOP compliance, mission-critical execution under pressure BestBuy, IL September’21 – September’23

Senior Software Developer

● Led development of a cross-platform e-commerce application using React Native, Redux, and JavaScript, delivering high-performance mobile experiences for both Android and iOS.

● Migrated backend service components to AWS Lambda for cost-efficient and scalable execution, and integrated AWS S3 for product media and user-uploaded asset storage.

● Implemented features like cart management, order tracking, and user authentication using REST APIs backed by Node.js services.

● Replaced Firebase with AWS DynamoDB for flexible, low-latency data storage, improving cart update throughput under load.

● Integrated Stripe for secure payments and enhanced checkout experience; incorporated AWS SNS for transactional notifications.

● Utilized Apollo Client and GraphQL for state management and data fetching; collaborated with backend developers to define API schemas.

● Set up Google Analytics with custom event tracking to monitor user engagement and conversion funnels, increasing engagement by 20%.

● Performed unit testing using Jest and implemented integration test coverage for critical purchase flows.

● Mentored junior developers and partnered with QA engineers to define robust test plans and release workflows.

Environment: AWS (Lambda, S3, DynamoDB, SNS), Node.js, JavaScript, React Native, GraphQL, Stripe, Jest, IntelliJ

Anthem, IL June’19 – August’21

Senior Software Developer

● Develop & design mobile apps using React Native.

● Designed and developed scalable mobile applications using React Native, incorporating AWS S3 for media content delivery and AWS Lambda for backend processing.

● Migrated legacy AngularJS and Java components to React and Node.js, increasing load performance by 30% and unifying the stack under modern JavaScript.

● Built internal tools and patient-facing dashboards using React, Redux, and RESTful services; collaborated with backend teams to modernize APIs using Node.js.

● Introduced DynamoDB for user session and profile data storage, providing low- latency reads for mobile interactions.

● Ran A/B experiments using Google Optimize to iterate on UI design and content placement; improved mobile engagement by 40%.

● Created asynchronous job flows using SNS/SQS for email and notification triggers within care coordination modules.

● Championed unit testing using Jest, integrated component tests with Enzyme, and drove improvements in app reliability and delivery velocity. Environment: AWS (Lambda, S3, DynamoDB, SNS/SQS), Node.js, React, React Native, Redux, Jest, Enzyme, IntelliJ

BCBS, IL October’17 – September’18

Senior Software Developer

● Designed and developed full stack of apis and their corresponding UI.

● Used Test Driven Development to cover the entire code base.

● Mockito and Jasmine frameworks are used for TTD frontend and backend apps.

● Design the solution and review the test plan with the QA engineers.

● Worked as Pair Programmer in Extreme Programming Environment. Environment: Intellij, Kotlin, Javascript, Docker, HTML, CSS Cloud Foundry. Samsung Telecommunications America, KA May’15 – October’17 Android Developer

● Understanding the OMADM UI requirements from the HQ in Korea as well as the carrier in the US.

● Design the UI in an AGILE development environment and work with UX.

● Develop the UI to be able to properly communicate and integrate with the OMADM Service for Carrier Admin.

● Design the solution and review the test plan with the QA engineers.

● Understanding the requirement from the carrier for the development of Chameleon Service for Carrier control of the devices.

● Implement JSON string parsing for the new carrier payloads and implement all carrier customizations on the Zero device.

● Tested the app across different versions of Android and tested them on different android phones to assure quality and performance.

Environment: Android Studio, Java SDK 1.7, SQLite 3.0, Eclipse IDE and ADT Plugin Fyllan Inc., KA December’16 - August’18

Android Developer

Guest App

● Fyllan is a startup which provides real-time on-demand platform for restaurants and users to maximize and monetize their time.

● Developed the entire app from early design stages to production release.

● Implemented in-app billing solutions using 3rd party library.

● Integrated Google maps and location services to get user current location and suggest restaurants nearby.

● Implemented new permission models for Android M+ devices.

● Integrated Firebase analytics for user analytics and crashlytics.

● Implemented material design patterns to make the app more user-friendly.

● Used the latest technology like Google app signing and Firebase analytics. Host App

● Login and Account creation functionality added for new restaurants.

● Account owner preference mode of payment is added using Stripe.

● Customize views are added in app.

● Various third party libraries like butterknife, retrofit, stripe are used.

● App is designed and developed only for tablets.

Environment: Android Studio, Java SDK 1.7, and ADT Plugin. Alstom Projects India Ltd., Noida, India Aug‘11 – July‘13 Software Developer

● Responsible for creating the entire Gas Turbine Model simulator using MATLAB and Java.

● Design Engineering and Logic Development for Gas Turbines.

● Testing of CONTROGAS logic using HIL set up and simulator.

● Creating IFSI (Initial Field Service Instruction) for Standard as well as project- specific issues.

● Gathering, analysis & module-level designing and development.

● Fixing the bugs identified in the test phase.

● Participating in Pre-FAT (Factory Acceptance Test) for gas turbines.

● Responsible for the project Execution of Tuas, Keppel and El Suaz from Noida office.

● Developing Process Function Plans (PFUPs), this is used as an input for the development of Gas Turbine Controllers.

Environment: Java, ControGas, ControCAD, MATLAB

Startup Consulting Roles, Remote Jan’19 – Dec’21

Consulting Mobile & Systems Engineer

3DRS (Airbnb for Long-Term Rentals)

● Designed and developed a full-featured cross-platform rental app in React Native for both Android and iOS, from initial prototype to app store release.

● Integrated Ethereum-based smart contracts for secure, transparent long-term rental transactions, including MetaMask wallet support.

● Engineered the backend using Firebase and Node.js to enable real-time sync, authentication, and notifications across devices.

● Implemented scalable architecture and modern UI patterns with Stripe payments and geo-location services.

Council Technology (Encrypted Messaging App)

● Architected a secure, privacy-first communication platform leveraging end-to-end encryption principles inspired by the Signal protocol.

● Migrated encryption-heavy operations from Flutter to native modules (Kotlin & Swift), increasing message throughput and performance by 40%.

● Developed secure key exchange mechanisms, device binding logic, and push notification workflows optimized for privacy compliance. Helium Software (Healthcare Research Platform)

● Led migration of legacy native mobile apps to a unified Flutter codebase for cost efficiency and feature parity.

● Built custom Flutter plugins for device hardware integration (BLE sensors, biometric interfaces) and accessibility support.

● Designed HIPAA-compliant user interfaces and workflows for medical study participants, balancing usability with regulatory compliance.

● Collaborated with cross-functional teams to improve user onboarding, retention, and adherence in longitudinal research studies.

Projects

Android Projects :

Build It Bigger

● Android App to show jokes using java and android libraries and using google cloud endpoints.

● Project contains a Java library for supplying jokes.

● Project contains an Android library with an activity that displays jokes passed to it as intent extras.

● Project contains a Google Cloud Endpoints module that supplies jokes from the Java library. Project loads jokes from GCE module via an AsyncTask.

● Project contains connected tests to verify that the AsyncTask is indeed loading jokes.

● Project contains paid/free flavors. The paid flavor has no ads and no unnecessary dependencies. Ads are shown in the free version.

● App retrieves jokes from Google Cloud Endpoints module and displays them via an Activity from the Android Library. Note that the GCE module need only be deployed locally.

Github Link - https://github.com/harry329/BuildItBigger StockHawk

● Android App to show stock quotes of selected companies.

● Each stock quote on the main screen is clickable and leads to a new screen which graphs the stock's value over time.

● Stock Hawk does not crash when a user searches for a non-existent stock.

● Stock Hawk Stocks can be displayed in a collection widget.

● Stock Hawk app has content descriptions for all buttons.

● Stock Hawk app supports layout mirroring using both the RTL attribute and the start/end tags.

Github Link - https://github.com/harry329/StockHawk CineFlick

● Android App to show new released and highly rated movies.

● Movies are displayed in the main layout via a grid of their corresponding movie poster thumbnails. UI contains an element ( settings menu) to toggle the sort order of the movies by: most popular, highest rated

● Movie details layout contains title, release date, movie poster, vote average, and plot synopsis.

● When a user changes the sort criteria (“most popular and highest rated”) the main view gets updated correctly.

● In the movies detail screen, a user can tap a button to mark it as a Favorite.

● The titles and ids of the user's favorite movies are stored in a ContentProvider backed by a SQLite database. This ContentProvider is updated whenever the user favorites or unfavorites a movie.

● When the "favorites" setting option is selected, the main view displays the entire favorites collection based on movie ids stored in the ContentProvider. Github Link - https://github.com/harry329/CineFlick IOS Projects :

PitchPerfect

● IOS App to record user voice and then play it out in other characters voice.

● Implemented multiple ViewControllers for different functionality in app.

● Implemented NavigationController and Segue to move from one screen to another.

● Used StackViews to properly aligned various UI elements.

● Record the user voice in audio format and pass between different views for core functionality of app.

Github Link - https://github.com/harry329/ios-pitchPerfect Cloud Projects:

Refactor Udagram App into Microservices and Deploy

● Refactored the app to run as a container on local file system.

● The app was containerized using Dockerfile in repo using which docker image can be built.

● Docker images were made publicly available using dockerhub.

● The application runs on a kubernetes cluster in the cloud.

● The app can be upgraded via rolling-update without downtime using kubernetes services.

Github Link - https://github.com/harry329/udacity-microservice-project Serverless ToDo

● Developed serverless app on aws cloud.

● Data was stored on aws dynamodb.

● LocalSecondary indexes & Global Secondary indexes used for data fetching from dynamodb.

● Event driven approach was adopted to send notifications using web sockets.

● Serverless framework was used to develop and deploy app to aws cloud.

● Postman collection made available on github.

Github Link - https://github.com/harry329/serverless React Projects:

MyReads

● Book app which have main page showing 3 shelves for books, Reading, WantToRead, Read.

● Each book is shown on the correct shelf, along with its title and all of its authors.

● The main page shows a control that allows users to move books between shelves.

● Search capability is provided to user to search for books.

● As the user types into the search field, books that match the query are displayed on the page, along with their titles and authors

● The search page contains a link to the main page. When the link is clicked, the main page is displayed and the URL in the browser’s address bar is /. Github Link - https://github.com/harry329/my-reads Machine Learning Projects :

PitchPerfect

● Created working model for predicting house prices using Boston housing dataset.

● All requested statistics like mean, median, standard deviation for the Boston Housing dataset are accurately calculated using numpy.

● Identified whether the hypothetical model successfully captures the variation of the target variable based on the model’s R^2 score.

● Training and testing split is correctly implemented in code.

● Identified the trend of both the training and testing curves from the graph as more training points are added.

● Used K-Cross validation technique in grid search technique to optimize the mode. Github Link - https://github.com/harry329/boston_housing Publications

Google Play Store Apps

Fyllan - Fyllan is startup which provides real time on demand platform for restaurants and users to maximize and monetize their time.

PlayStore Link Guest - https://play.google.com/store/apps/details?id=com.fyllan.fyllan.guest PlayStore Link Host- App only available for alpha testers right now. Ribbitt - Android application for sending photos and videos messages which auto-delete. PlayStore Link- https://play.google.com/store/apps/details?id=com.developer.harry.ribbitt Source Code - https://github.com/harry329/Ribbitt

Stromy-Weather Application for Android Devices

PlayStore Link - https://play.google.com/store/apps/details?id=developer.harry.com.stromy Source Code - https://github.com/harry329/Stromy

LinkedIn Link - linkedin.com/in/singh-harsimran

Github Profile - https://github.com/harry329

Blog - https://androidandbrillo.wordpress.com/

Education:

University at Buffalo, The State University of New York Aug‘13 – Dec‘15 Masters in EE; GPA 3.86

N.I.T-Jalandhar, India Aug‘07 – May‘11

Bachelor of Technology, Instrumentation and Control Engineering Certificates:

Product Management Certificate from Product School AI Programming with Python Nanodegree

Cloud developer Nanodegree

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