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Pawan Mittal

📍 San Diego, CA
📞 1 858 288 3709
mitpawan@gmail.com

Summary​

  • 16 years of professional experience in software engineering with a strong focus on backend and full-stack development.
  • Passionate about building data-driven systems and modeling complex, real-world behaviors.
  • Experienced in designing scalable architectures for high-volume data processing and interactive visualizations.
  • Strong technical writer and communicator, with a knack for mentoring, teaching, and simplifying complex ideas.
  • Enjoys experimenting with code, exploring new technologies, and translating concepts into practical solutions.

Work Experience​

Creator & Developer | notjustpython | Ongoing | San Diego, CA​

An educational app blog demonstrating real-world software architecture using microservices and modern technologies.

  • Dev Ops
    • Designed and developed containerized microservices, each showcasing a different tech stack.
    • Configured Nginx as a reverse proxy, with each microservice running on its own port for isolation.
    • Deployed the platform on Amazon Lightsail VPS for cost-effective hosting with root-level control.
  • APIs
    • Built multiple backend services in Python (Flask), demonstrating RESTful APIs, JWT auth, OAuth2 login, and secure session handling.
    • Implemented proof-of-concepts for core backend concepts like functional programming, data pipelines, and message queues.
    • Developed demo applications and APIs using Node.js, integrated into a custom Express server.
  • UI
    • Built user-facing interfaces using React, styled with CSS.
    • Integrated Axios for API communication across services.
    • Used Docusaurus to generate static documentation-style walkthroughs with embedded code, explanations, and interactive learning.
    • Managing JavaScript dependencies via npm to support evolving frontend needs.
  • Mentoring
    • Created hands-on tutorials that promote building, breaking, and iterating — not just reading about concepts.
    • Targeted at engineers who learn best through exploration and experimentation.

Lead Python Engineer | Feature Analysis for Stock Trading (FAST) | Mar 2022 – Nov 2024 | San Diego, CA​

A research-focused stock trading platform that leverages statistical models, time-series data, and machine learning to discover patterns and generate actionable trade recommendations targeting short-term gains (e.g., 5% in 1–3 days).

  • Machine Learning & Feature Engineering
    • Devised stock features to normalize price and volume data.
    • Built a pipeline to group and scale time series data, enabling consistent model inputs across tickers and exchanges.
    • Developed a CLI-driven training framework to experiment with combinations of features, lookback periods, and target definitions.
    • Trained and evaluated multiple models including:
      • Logistic Regression models using scikit-learn for binary classification of trade outcomes
      • Recurrent Neural Networks (RNNs) using TensorFlow, with stacked GRU layers, dropout regularization, and sigmoid output for binary classification
      • Tuned RNN hyperparameters like lookback length, GRU units, dropout rate, and learning rate to avoid overfitting and improve predictive performance
    • Applied time series-aware feature scaling and created rolling lookbacks to model short-term directional changes.
    • Defined flexible labeling logic to support variable holding periods and profit thresholds, allowing dynamic target generation.
    • Evaluated model performance using metrics such as precision, recall, accuracy, and F1 score for downstream analysis and comparison across models.
    • Persisted trained models to the filesystem for per-ticker evaluation and inference.
  • UI
    • Built a responsive, user-friendly interface using React hooks, JSX, Babel, HTML, and CSS.
    • Integrated Axios for seamless API communication between frontend and backend.
    • Configured Nginx to serve frontend assets and manage static/dynamic content efficiently.
  • API & Data Analysis
    • Engineered a robust Python API for serving trade signals and user data.
    • Used Pandas for data import, transformation, analysis and statistical modeling.
    • Deployed backend services using uWSGI.
  • Database
    • Designed schema for MongoDB collections for storing stock data, generated features, and user activity.
    • Used MongoEngine ODM to abstract database access through Python classes.
    • Applied design patterns including DAO, MVC, to develope a modular code base.
  • DevOps
    • Configured Nginx as a reverse proxy to route frontend and backend traffic across services running on different ports.

Lead Python Engineer | DailyStockStats | Dec 2021 – Mar 2022 | San Diego, CA​

A data-driven web portal offering visual insights into daily price and volume trends across U.S. stock exchanges.

  • Data Visualization
    • Integrated interactive charts using Highcharts to display daily movements, and stock-specific statistics.
  • Data Pipeline
    • Fetched intraday and daily stock data using the Polygon.io API.
    • Parsed, validated, and stored structured time-series data using Pandas for downstream processing.
  • API
    • Built RESTful API endpoints using Flask and MongoDB for efficient data delivery.
    • Implemented secure OAuth2 login with Google, using JWT tokens and session cookies for authentication and user session management.
    • Managed asynchronous data pipelines with Celery and Redis, enabling scheduled data pulls, and background updates.
    • Implemented custom middleware using Flask hooks (before_request, after_request) for request tracking, and performance monitoring.
  • DevOps
    • Deployed the backend using uWSGI + Nginx with production-grade configuration.
    • Automated service startup systemd (systemctl).
    • Enabled SSL with HTTPS for secure public access to the site.
    • Added configuration management using .env files and Python's configparser to support local, staging, and production environments.

Senior Software Engineer | Direct Commerce | May 2018 – Mar 2021 | San Francisco, CA​

Developed and supported an Accounts-to-Pay (A2P) portal handling high-volume purchase order data from major U.S. retailers including Walmart and Home Depot.

  • Data Pipeline
    • Built and maintained batch pipelines to ingest, transform, and validate POs using Linux scripts, CRON, JDBC, SFTP, and PostgreSQL.
    • Ensured timely and accurate processing of large datasets from external systems, with emphasis on reliability and failure recovery.
  • Communication & Production Support
    • Acted as primary point of contact for error handling and data discrepancies, working directly with clients to resolve processing issues.
    • Provided production support during critical business hours, triaging high-priority issues and restoring service continuity.
  • Frontend & Prototyping
    • Enhanced and maintained user-facing features using JSP, AJAX, and JavaScript to streamline vendor interactions.
    • Prototyped backend services with Spring Boot to enable modularization with microservices.
  • Testing & Build Automation
    • Authored unit tests using JUnit to ensure consistent behavior across backend modules.

Sr. Java Developer | Macy’s (Omnichannel Pricing Team) | May 2014 – Apr 2018 | San Francisco, CA​

Delivered consistent pricing experiences across online and in-store platforms by building robust pricing services and ensuring cross-platform integration.

  • System Integration & Messaging
    • Developed a centralized pricing engine using Java and Tibco JMS to facilitate reliable communication between in-store systems and Macys.com.
  • Cross-Functional Support
    • Mentored junior developers and supported Quality Engineering (QE) teams during testing and defect triage.
    • Collaborated with distributed teams across time zones to align on development and deployment cycles.
  • DevOps & Release Management
    • Managed continuous integration pipelines with Jenkins and participated in release planning alongside engineering leadership.
  • Tech Stack
    • Java, Spring, REST APIs
    • jQuery, Backbone.js
    • JPA, Hibernate, SQL
    • JBoss, JIRA

Lead Technology Engineer | Wired Digital (Wired.com) | Nov 2011 – May 2014 | San Francisco, CA​

Led engineering efforts for Wired Digital - a high-traffic news and media site by supporting editorial workflows, launching new features, and ensuring performance.

  • Platform Engineering & CMS Support
    • Maintained and enhanced Wired.com’s custom CMS and WordPress-based editorial tools, ensuring reliability for daily publishing operations.
    • Partnered closely with editorial and product teams to implement new features and content workflows with minimal editorial friction.
  • Feature Development & System Migration
    • Spearheaded the migration of the Wired Curator App from Grails/Oracle to CakePHP/MySQL stack.
  • Revenue Recovery & Performance Optimization
    • Revamped the site's RSS feed architecture to maintain ad revenue continuity following the deprecation of FeedBurner.
    • Monitored platform performance, conducted load testing, and optimized backend queries to support heavy traffic surges during major news events.
  • Integrations & Widgets
    • Developed real-time interactive widgets that visualized engagement from third-party platforms like Ning, and Disqus
  • Tech Stack
    • PHP, WordPress, CakePHP
    • MySQL, Oracle
    • JavaScript, jQuery
    • Grails, RSS/XML

Software Developer | Williams-Sonoma, Inc. | Mar 2011 – Oct 2011 | San Francisco, CA​

Contributed to the core e-commerce platform of Williams-Sonoma.com, building new features and optimizing key backend workflows.

  • Feature Development
    • Developed new features using Spring MVC, Hibernate, and Java/J2EE, supporting both customer-facing and admin-facing components.
  • Marketing & Tracking Integration
    • Integrated DART Floodlight Tags for campaign performance tracking and digital marketing attribution.
    • Worked with analytics stakeholders to validate tag placement and data capture accuracy.
  • Tech Stack
    • Java, Spring MVC, Hibernate
    • JSP, JavaScript
    • DART/DoubleClick tracking

Software Developer | Wells Fargo | Mar 2010 – Mar 2011 | San Francisco, CA​

Developed and maintained backend systems for loan data verification in a regulated banking environment.

  • System Redesign
    • Rewrote core logic for the Loan Data Integrity Check (LDIC) system to improve validation accuracy and maintainability.
  • Database & Web Services
    • Designed SQL schemas and developed stored procedures to support data validation and reporting pipelines.
    • Built Java-based web services using SOAP for system integration and external service communication.
  • Testing & QA Support
    • Automated test scripts to accelerate QA cycles and reduce manual testing effort.
    • Supported QA in resolving bugs and deployment issues across multiple test tiers.
  • Tech Stack
    • Java, SOAP Web Services, WSDL
    • SQL, Stored Procedures
    • Shell Scripting, QA Automation

Java Developer | JPMC Xign | Apr 2009 – Mar 2010 | Pleasanton, CA​

Maintained and enhanced the enterprise e-invoicing platform at Xign (a JPMorgan Chase subsidiary), focusing on framework improvements, client customizations, and production support.

  • Framework & Backend Development
    • Maintained and extended the in-house MVC framework, custom tag libraries, and ORM tools to support scalable platform development.
    • Built XSLT templates to convert XML-based data into POJOs for integration with internal services.
  • Client Customization & Implementation
    • Collaborated with the implementation team to tailor solutions for enterprise clients across diverse industries.
    • Conducted impact analysis, code reviews, and authored QA test cases to ensure stable deployments.
  • Case Management
    • Served as interim team lead, managing task prioritization and case handling via Salesforce.
    • Acted as liaison between engineering, QA, and implementation teams to resolve cross-functional issues.
  • Tools & Tech
    • Java 1.4, WebLogic, Eclipse
    • Oracle 10g, TOAD
    • Perforce, Salesforce, XML/XSLT

Java Developer | Visa | Jun 2008 – Jan 2009 | Foster City, CA​

Contributed to backend services for credit card data processing, and collaborated with business stakeholders.

  • Application Development
    • Translated business use cases into backend services using Java and Spring Dependency Injection (DI) for modular code structure.
    • Improved performance in large-scale credit card data processing by implementing batching strategies to optimize input handling.
  • Testing
    • Wrote detailed unit and integration test cases to support functional correctness.
    • Worked closely with QA teams to resolve discrepancies uncovered during formal testing cycles.
  • Stakeholder Engagement
    • Partnered with business analysts and product managers to align technical design with business requirements and compliance standards.
  • Tech Stack
    • Java, Spring DI, JUnit
    • Batch Processing, Oracle

Developer Analyst | Scottsdale Insurance Company | Oct 2007 – May 2008 | Scottsdale, AZ​

Built and enhanced internal tools to streamline insurance classification workflows and improve document accessibility.

  • Web Application Development
    • Developed a web-based CMS for searching, editing, and printing internal classification guides used by underwriters.
    • Delivered iterative enhancements based on user feedback.
  • UI/UX
    • Converted Photoshop mockups into interactive web pages using HTML, CSS, and JavaScript.
    • Ensured cross-browser compatibility and consistent styling for internal enterprise users.
  • Tech Stack
    • HTML, CSS, JavaScript
    • Web-based CMS, Adobe Photoshop

Developer | Department of Economic Security | Feb 2007 – Sep 2007 | Phoenix, AZ​

Built secure, enterprise application to support government benefits and eligibility systems.

  • Application Development
    • Built an N-tier Java application using Spring MVC, iBatis, and Freemarker for dynamic page generation and backend data access.
    • Developed modular components for input forms, business workflows, and data persistence.
  • Reporting Engine
    • Engineered a custom PDF reporting engine using XSLT, XQuery, and Apache Formatting Objects (FOP) to generate print-ready PDF documents.
  • Security & Legacy Integration
    • Secured the application using Acegi Security (Spring Security predecessor) for role-based access control and authentication.
    • Created SOAP clients using Axis to interface with legacy mainframe systems and state databases.
  • Tech Stack
    • Spring, iBatis, Freemarker, JSP
    • Axis, Acegi Security, Apache FOP
    • Tomcat, JBoss, Ant, CVS
    • CSS, XSLT, XQuery