
Lav Kumar Vishwakarma
Verified Expert in Engineering
Web Security Developer
Bhopal, Madhya Pradesh, India
Toptal member since June 24, 2022
Lav is a back-end and AI engineer with 10+ years of experience building scalable, distributed systems, now focused on taking AI agents from pilot to production. He scaled GrowthDay to 400,000+ users, shipped two production AI systems—a RAG coaching avatar and a crash-triage agent that opens pull requests—and built scheduling infrastructure used by Google and Telefónica. Acknowledged by 100+ companies for security research, he recently reported three vulnerabilities in AWS MCP servers.
Portfolio
Experience
- Web Security - 7 years
- Back-end - 7 years
- REST - 7 years
- Go - 6 years
- PostgreSQL - 6 years
- Microservices - 5 years
- gRPC - 5 years
- Java - 4 years
Preferred Environment
Go, PostgreSQL, gRPC, REST, Microservices, Docker, Claude API, OpenAI API, LangGraph, AI Agents
The most amazing...
...things I've built are production AI agents serving 400,000+ users at GrowthDay and scheduling infrastructure used by Google and Telefónica.
Work Experience
Adobe Analytics Developer
UChicago Medicine
- Designed and built a HIPAA-compliant Customer Journey Analytics (Adobe CJA) pipeline for a major US academic health system, covering XDM schema design and a complete funnel event taxonomy across patient-facing web properties.
- Conducted a PHI audit of the analytics stack, identifying and remediating fields where protected health information could leak into collection, and defining governance rules to keep the pipeline compliant.
- Authored handoff documentation and trained the internal team, ensuring the pipeline remained maintainable after the engagement.
Google Analytics 4 Expert
Summit Health
- Architected Salesforce-driven personalization for a multi-state US healthcare network, connecting CRM data to on-site experiences while keeping PHI out of marketing systems.
- Designed and implemented marketing automation flows across web and CRM, replacing manual processes and previous tools and standardizing campaign event tracking.
- Set up BigQuery-based reporting connecting web analytics with CRM outcomes, giving marketing teams visibility into funnel performance and campaign attribution.
- Ensured privacy-compliant data collection across the stack, including consent management integration.
Independent Security & AI Researcher
Independent Security & AI Researcher
- Reported three vulnerabilities in AWS MCP (Model Context Protocol) servers in 2026—all accepted, responsible disclosure in progress—as part of ongoing research into AI agent attack surfaces.
- Acknowledged and rewarded by 100+ companies, including AT&T, Opera (Hall of Fame), Airwallex, Check24, and the University of Michigan for responsibly disclosed vulnerabilities, including critical findings exposing production systems.
- Authored memory-blackbox, an open-source append-only memory provenance layer that makes AI agent incidents reconstructable—what the agent knew, when, and why it acted.
- Conducted BLE/IoT security research into battery management systems, currently in responsible disclosure.
Lead Software Engineer
GrowthDay
- Oversaw the development of back-end application architecture and system design for a personal development platform that includes live coaching sessions to help 400,000 active users build confidence, develop good habits, and improve their lifestyles.
- Spearheaded the development of a new enterprise product to introduce the GowthDay brand to SMEs and help each client build successful teams, emphasizing good communication, fostering company culture, and driving efficiency at scale.
- Developed new platform features, including a video conferencing system, enabling collaborative learning and gift subscriptions to drive user growth.
- Collaborated with executive stakeholders and design, front-end, and product teams to define technical product requirements, determine product features, and streamline an overall development roadmap.
- Supervised hiring and training of a back-end development team and collaborated with cross-functional leaders to deliver multiple complex projects.
- Shipped Brendon AI, a retrieval-augmented (RAG) coaching avatar with an in-house feedback engine, serving the full 400,000+ user base.
- Built an internal AI agent that ingests crash reports, root-causes them, and opens pull requests with candidate fixes—sustaining over 99.99% crash-free sessions.
Back-end Engineer
GrowthDay
- Led the revamp of the back-end development by rebuilding the app's core pillars from scratch, improving development processes, optimizing the developer experience, and driving enhancements to enable reusability, security, and increased performance.
- Enhanced the API performance and made it production-ready by implementing notifications, error reporting, centralizing logging, scaling, improving the response time, and providing support for regulatory compliance.
- Contributed to different analytics platform integrations like the Facebook pixel, Mixpanel, Google Analytics, and AppsFlyer.
Lead Software Engineer
Appointy
- Led the development of SaaStack, a SaaS platform, including designing the plug-and-play architecture for the back end with inbuilt scaling, security, and regulatory compliance handling.
- Contributed to core architecture layers, including authentication, roles and rights, licensing, logging, tracing, and scalability.
- Developed new features for SaaStack to support people, account, client billing, and enterprise management using Go, GraphQL, gRPC, and PostgreSQL.
- Enhanced performance, reducing the API response times from two seconds to less than 150 milliseconds.
- Assisted with the scaffolding app's command-line interface tools by leveraging Relay as a GraphQL client to eliminate the codebase set-up time and leveraging a protocol buffer to generate the Go service codebase.
- Decreased development time and maximized development flexibility by developing a set of code generation tools based on easy-to-use annotations and reduced the development time by 80% of code generation.
- Created guides and checklists for developers, worked on improving developer experience, and mentored developers to increase their efficiency.
Product Developer
Appointy
- Developed Appointy's small-to-large business scheduling tool based on microservice architecture. The tool is used by one million people.
- Evaluated integration libraries and tools to shorten the development time from one year to one month. Designed microservices and the micro front-end architecture to help further optimize development.
- Advised and oversaw client development by creating user flows, product roadmaps, and features with a team of eight back-end developers.
- Created a new product that coordinated fitness classes, restaurants, and spa scheduling for Google.
- Built a room conference scheduling system for Telefonica, one of Spain's largest telecom companies, with features for managing rooms, scheduling calendars, staffing, and CMS and TMS integrations.
Associate Product Developer
Appointy
- Integrated a stripe payment system for accepting recurring and one-time payments and created a payment monitoring system to track and manage payments.
- Worked on the spam email checker script, which verified the existence of emails and reduced the email bounce rate by 99.9%.
- Reviewed system implementation for getting more reviews from the customers and increased the review ratio by 40%.
Experience
Conferencing Portal for Telefonica
GrowthDay App
http://www.growthday.comAppointy X
SaaStack
https://saastack.ioAppointy 9
Brendon AI — RAG Coaching Avatar (Growthday.com)
I owned retrieval design, grounding, and the evaluation loop, serving 400,000+ users.
Crash-triage AI Agent
memory-blackbox
https://github.com/lavkumarv/memory-blackboxEducation
Master's Degree in Cyber Security
Rajiv Gandhi Proudyogiki Vishwavidyalaya - India
Bachelor's Degree in Computer Science
University Institute of Technology, RGPV - Bhopal, India
Certifications
Claude Certified Architect - Foundations (CCA-F)
Anthropic
Certified Ethical Hacker (CEH)
EC-Council
Skills
Libraries/APIs
Protobuf, Stripe, Stripe API, Node.js, Authorize.net, Mixpanel API, Twilio API, Pushwoosh, Web API 2, Claude API, OpenAI API, Google Analytics API
Tools
GoLand, Git, Jira, IntelliJ IDEA, Sentry, Zapier, Microsoft Excel, RabbitMQ, NGINX, Miro, Keycloak, OneSignal, Jenkins, Google Analytics, ChatGPT, Istio, Amazon Elastic Container Service (ECS), BigQuery, Adobe, Adobe Analytics
Languages
Go, Java, GraphQL, HTML, SQL, C#, CSS, JavaScript, Bash Script, Python
Frameworks
OAuth 2, gRPC, JSON Web Tokens (JWT), Spring Boot, Express.js, Hydra, .NET 5, .NET Core, LangGraph
Paradigms
REST, Microservices, Serverless Architecture, Web Architecture
Platforms
Google Cloud Platform (GCP), Software Design Patterns, Docker, Azure, Amazon Web Services (AWS), Windows Server, Linux, Zoho CRM, LearnWorlds, Kubernetes, Kajabi, Mixpanel, MacOS, Salesforce
Storage
PostgreSQL, SQL Server 2017, MongoDB, Redis, MySQL, Memcached, Elasticsearch, Azure Active Directory, SQL Server 2016
Other
Software Development, Web Security, WebSockets, NATS, Server Security, Cloud Security, Development, Architecture, Documentation, Payment APIs, Web Server (IIS), Software as a Service (SaaS), Identity Server, Back-end, Zoho, APIs, Back-end Development, Cloud Services, Sharding, LDAP, Domain-driven Design (DDD), Telemetry, Load Balancers, Square, Apple Pay, TMS, Analytics, SAML-auth, Scalable Architecture, Maps, Airtable, Customer Relationship Management (CRM), Infrastructure Security, IIS 7, ECS, IIS, OAuth, PayPal, System Implementation, Security, AI Agents, Agentic AI, LLM Integration, RAG Pipelines, Google Tag Manager, Marketing Automation, CRM, Dashboard Development, AI Security
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