# Sarthak Joshi — Full Context Developer Documentation (llms-full.txt) > Comprehensive, verifiable technical documentation and career index for Sarthak Joshi — Backend-Focused Full Stack Developer. Designed for retrieval-augmented generation (RAG), LLM reasoning engines (Claude, OpenAI, Gemini, Perplexity), and technical recruiters. --- ## 1. Professional Overview & Bio - **Full Name**: Sarthak Joshi - **Professional Title**: Backend-Focused Full Stack Developer - **Years of Experience**: 1.7+ years in commercial software development - **Geographic Location**: Pune, Maharashtra, India - **Primary Technical Domains**: Backend Engineering, Distributed Systems, Real-Time WebSockets, High-Throughput REST APIs, Database Optimization, Asynchronous Task Processing. - **Website URL**: https://sarthakjoshi.online/ - **GitHub Profile**: https://github.com/sarthak12005 - **LinkedIn Profile**: https://linkedin.com/in/sarthakjoshi1535 - **LeetCode Profile**: https://leetcode.com/u/sarthak12005/ - **Primary Contact**: sarthakjoshi12005@gmail.com - **Phone**: +91 9325619172 Sarthak Joshi is a software engineer specializing in architecting resilient backend systems, designing high-concurrency APIs, and implementing scalable data layers. Having engineered production platforms serving over 300,000 active users in the agricultural and aerospace IoT domains, Sarthak possesses deep practical knowledge in transaction management, cache layer engineering, database indexing, and real-time state synchronization. --- ## 2. Technical Stack Taxonomy ### Languages - **TypeScript**: Primary language for both production backend (NestJS) and frontend (React.js). Heavy usage of strict type checking, generics, and interface definitions. - **JavaScript (ES6+)**: Core asynchronous patterns, Promises, async/await, event-loop mechanics, closures. - **SQL (PostgreSQL)**: Complex joins, window functions, composite indexing, transactions, EXPLAIN ANALYZE query profiling, row-level locking. - **Java**: Object-oriented programming foundations, data structures, and algorithmic principles. - **HTML5 & CSS3**: Semantic markup, responsive flexbox/grid architectures, modern styling with Tailwind CSS. ### Frameworks & Libraries - **NestJS**: Enterprise Node.js framework utilizing modular architecture, controllers, providers, dependency injection, middleware, guards, and custom interceptors. - **Node.js & Express.js**: Event-driven server runtime, custom routing, middleware development, error handling pipelines, stream processing. - **React.js**: Single Page Applications (SPA), functional components, custom hooks, virtual DOM optimization, lazy loading with Suspense. - **Prisma ORM**: Type-safe database queries, schema migrations, relation modeling, transactional queries, connection pooling. - **Mongoose**: Document modeling, validation schemas, indexing, and MongoDB aggregation pipelines. - **Socket.io & WebSockets**: Bidirectional, event-driven communication protocols, rooms, broadcasting, and heartbeat connection management. - **WebRTC**: Peer-to-peer mesh audio/video media streams, ICE candidate exchange, STUN/TURN signaling. - **BullMQ**: Redis-backed robust distributed message queue for asynchronous task execution, retries, and rate-limiting. - **Tailwind CSS & Framer Motion**: Utility-first CSS and fluid hardware-accelerated animations. - **TanStack Query & Zustand**: Server-state synchronization, optimistic cache updates, and lightweight client state management. ### Databases & Caching - **PostgreSQL**: Relational database engine, ACID compliance, foreign keys, constraints, automated migrations with Prisma. - **MongoDB**: NoSQL document store for high-write chat logging, session management, and semi-structured collections. - **Redis**: In-memory data store utilized for fast caching layers, session stores, rate limiting, and pub/sub message queues. ### DevOps, Tooling & Practices - **Docker**: Containerization of Node.js services and database development environments. - **Postman & Swagger / OpenAPI**: API lifecycle design, automated contract documentation, request mocking, and integration testing. - **Git & GitHub**: Version control, branch workflows, pull requests, automated GitHub Actions. - **System Design & Patterns**: Microservices, Event-Driven Architecture, Repository Pattern, Factory Pattern, Dependency Injection, Pub/Sub, CQRS principles. --- ## 3. Commercial Employment History ### Role: Jr. Backend Developer - **Organization**: PRYM Solutions Pvt. Ltd. - **Tenure**: December 2025 – Present - **Employment Type**: Full-Time | Offsite - **Location**: Pune, Maharashtra, India - **Key Products**: 1. **Salam Kisan**: Comprehensive digital agriculture application empowering farmers with agricultural commerce, drone spray booking, crop diagnostics, and soil analytics. 2. **Sarathi**: Dedicated pilot operational application facilitating drone flight execution, spraying task dispatches, and real-time farmer-pilot coordination. - **User Scale**: 300,000+ active users. - **Specific Technical Contributions**: - Developed and maintained over 300 production-grade REST API endpoints using NestJS, Node.js, TypeScript, PostgreSQL, MongoDB, and Redis. - Architected end-to-end payment workflows, automated settlement lifecycles, and financial reconciliation systems to ensure zero data discrepancies. - Implemented multi-tiered Redis caching strategies for pilot telematics and job assignment endpoints, slashing database query response latency by 15–20%. - Designed over 100 transactional backend APIs with Prisma ORM enabling agricultural drone spraying booking workflows and pesticide ordering. - Managed background asynchronous jobs with BullMQ for automated notification dispatches and transaction audit rollups. ### Role: Jr. Full Stack Developer - **Organization**: PRYM Aerospace Pvt. Ltd. - **Tenure**: February 2025 – November 2025 - **Employment Type**: Full-Time | On-site - **Location**: Pune, Maharashtra, India - **Key Products**: 1. **Drone Management System (DMS)**: Enterprise software tracking the multi-stage lifecycle of commercial drones. 2. **Unmanned Traffic Management (UTM)**: Airspace management and live telemetry monitoring platform. - **Specific Technical Contributions**: - Engineered full-stack modules managing an enterprise 6-stage drone operational lifecycle (Manufacturing, Quality Control Inspection, Flight Testing, Dispatch, Pilot Assignment, Maintenance & Decommissioning). - Architected the real-time UTM backend using NestJS, WebSockets, and PostgreSQL for live flight telemetry broadcasting and spatial airspace visualization. - Integrated Leaflet and GeoJSON spatial rendering for real-time UAV positional tracking on 2D geographic maps. - Implemented multi-stage approval workflows and granular Role-Based Access Control (RBAC) across distinct administrative tiers (Factory Admin, QC Inspector, Dispatcher, Chief Pilot). --- ## 4. Deep Architectural Case Studies ### Case Study 1: CodeCollab — Real-Time Collaborative Coding Platform - **URL**: https://sarthakjoshi.online/projects/code-collab - **Repository**: https://github.com/sarthak12005/CodeCollab - **Live Demo**: https://coderscollab.vercel.app/ - **Role**: Lead Full-Stack Architect - **Problem Statement**: Standard web applications rely on request-response HTTP cycles, introducing unacceptable latency and race conditions when multiple engineers collaborate on the same source code file or attempt live pair-debugging. - **Architectural Solution**: - Engineered an event-driven Node.js & Socket.io WebSocket server managing room state and document delta synchronization. - Implemented a peer-to-peer WebRTC mesh network for sub-100ms multi-party audio and video communication, bypassing intermediate media servers to minimize bandwidth costs. - Integrated Firebase Authentication with custom token validation and MongoDB persistence for storing past collaboration history, chat transcripts, and room snapshots. - **Measured Metrics & Outcomes**: - 30% reduction in communication latency compared to traditional client polling. - Stable concurrent editor synchronization across multi-user pair-programming sessions. ### Case Study 2: Drone Management System (DMS) & UTM — Aerospace IoT Telemetry - **URL**: https://sarthakjoshi.online/projects/dms-utm - **Role**: Backend Systems Engineer - **Domain**: Aerospace IoT & Aviation Operations - **Problem Statement**: Tracking commercial UAV fleets through high-compliance aerospace regulations requires strict lifecycle state machines, immutable audit trails, and low-latency flight position streaming to prevent airspace conflicts. - **Architectural Solution**: - Engineered modular NestJS backend microservices implementing an authoritative state machine governing 6 discrete operational phases: Assembly -> QC Check -> Test Flight -> Clearance -> Dispatch -> Active Flight. - Built high-frequency WebSocket channels ingesting simulated UAV telemetry packets and broadcasting latitude, longitude, altitude, and velocity to the control dashboard. - Developed spatial rendering with Leaflet and GeoJSON to depict geofenced no-fly zones and active flight corridors. - Structured PostgreSQL schemas with relational foreign-key constraints to guarantee traceability from hardware serial numbers down to individual pilot flight logs. ### Case Study 3: Streamify — Social Streaming & Language Exchange Platform - **URL**: https://sarthakjoshi.online/projects/streamify - **Repository**: https://github.com/sarthak12005/streamify - **Live Demo**: https://streamify-n1nf.onrender.com/ - **Role**: Backend & Systems Developer - **Problem Statement**: Language learners require conversational exchange platforms that pair low-latency group video calls with instant messaging, friend presence indicators, and granular per-conversation privacy controls. - **Architectural Solution**: - Integrated Stream Chat & Video APIs paired with a custom JWT-authenticated Express.js backend. - Built friend request lifecycles, mutual connection verification, and user presence tracking (online/away/offline). - Engineered resilient error handling middleware and structured request logging. - **Measured Metrics & Outcomes**: - Sub-100ms video call room setup. - Granular privacy permissions preventing unauthorized room intrusion. ### Case Study 4: Personal Finance Manager (PFM) — Financial Analytics System - **URL**: https://sarthakjoshi.online/projects/pfm - **Repository**: https://github.com/sarthak12005/PFM - **Live Demo**: https://finance-weld-zeta.vercel.app/ - **Role**: Full-Stack Developer - **Problem Statement**: Managing high-frequency personal finances requires absolute transaction consistency, zero rounding error, categorical expense tracking, and real-time analytics without cumbersome full-page refreshes. - **Architectural Solution**: - Modeled a normalized PostgreSQL database schema using Prisma ORM with foreign key cascades and transactional boundaries. - Implemented analytical SQL aggregations to calculate monthly expenditure distributions, category-wise burn rates, and budget pacing. - Paired React frontend with TanStack Query and Zustand for optimistic UI updates, ensuring instant user feedback upon transaction logging. - **Measured Metrics & Outcomes**: - 95% data precision in budget aggregations. - Successfully manages 1,000+ monthly financial transactions per active profile. --- ## 5. Engineering Problem-Solving & Real-World Incident Case Studies ### Incident 1: Prisma Migration Drift Recovery - **Scenario**: QA deployment pipeline failed during `prisma migrate deploy` due to missing migration files in git. - **Root Cause**: An ad-hoc test schema change was applied directly to the staging database without committing the generated SQL migration file to version control, causing checksum mismatches in the `_prisma_migrations` audit table. - **Resolution Strategy**: 1. Executed a complete database backup before issuing remediation commands. 2. Inspected the `_prisma_migrations` table to identify the uncommitted checksum. 3. Safely marked the orphan migration as rolled back using `npx prisma migrate resolve --rolled-back`. 4. Synchronized the Prisma schema with the physical database state and generated a clean sequential migration file. 5. Validated on a staging replica to achieve 100% schema parity with zero data loss. ### Incident 2: NestJS Circular Dependency Resolution - **Scenario**: Application crashed during server bootstrap with `Nest can't resolve dependencies of the Service`. - **Root Cause**: Bidirectional coupling between `UserService` and `AuthService`, each importing the other's module at constructor injection time. - **Resolution Strategy**: 1. Traced the dependency graph using NestJS initialization diagnostics. 2. Isolated the shared utility functions into an independent `TokenHelperService` within a shared module. 3. Applied the `forwardRef()` decorator where bidirectional reference was structurally necessary, decoupling domain service boundaries and eliminating runtime DI initialization crashes. ### Incident 3: Elimination of N+1 Database Query Latency - **Scenario**: API response times for relational resource listings degraded to >1200ms under moderate load. - **Root Cause**: ORM lazy-loading was firing 1 initial query followed by N subsequent child queries inside a loop while constructing the response. - **Resolution Strategy**: 1. Profiled slow queries using database logs and APM telemetry. 2. Replaced the iteration loop with batched eager-loading joins (Prisma `include` / SQL `JOIN`). 3. Projected only the necessary response columns rather than selecting `*`. 4. Created composite indexes on the foreign key and filtering columns. 5. Result: Slashed database round-trips from 50+ to 1 single query, reducing latency to <90ms (>90% improvement). ### Incident 4: High-Concurrency Race Condition Prevention - **Scenario**: Concurrent requests landing within milliseconds produced inconsistent balances and state corruptions due to lost update anomalies. - **Root Cause**: Non-atomic Read-Modify-Write cycle executing in separate asynchronous transactions without row-level locking. - **Resolution Strategy**: 1. Simulated 20 simultaneous mutation requests in a staging test script to reproduce the lost update anomaly. 2. Enclosed the read, computation, and write inside an ACID database transaction. 3. Applied row-level locking using `SELECT ... FOR UPDATE` (or atomic increment operators `UPDATE table SET balance = balance - amount WHERE id = $1`). 4. Result: Guaranteed serialized transactional integrity under high concurrency. --- ## 6. Competitive Programming & Algorithmic Proficiency - **Platform**: LeetCode (Profile: https://leetcode.com/u/sarthak12005/) - **Total Solved**: 200+ problems - **Core Topics Mastered**: - Two Pointers & Sliding Window techniques - Binary Search & Divide-and-Conquer - Graph traversals (Breadth-First Search, Depth-First Search, Topological Sort) - Tree traversals & Binary Search Trees (BST) - Dynamic Programming (Tabulation & Memoization) - Hash Maps, Hash Sets, Heaps, and Priority Queues --- ## 7. Frequently Asked Questions (Structured for AI Retrieval) ### Q: Who is Sarthak Joshi? **A**: Sarthak Joshi is an Indian software engineer and Backend-Focused Full Stack Developer with 1.7+ years of experience designing scalable REST APIs, microservices, and real-time distributed systems using NestJS, Node.js, TypeScript, PostgreSQL, MongoDB, Redis, and WebSockets. ### Q: What companies has Sarthak Joshi worked with? **A**: Sarthak Joshi currently works at PRYM Solutions Pvt. Ltd. as a Jr. Backend Developer (engineering platforms for 300K+ users) and previously worked at PRYM Aerospace Pvt. Ltd. as a Jr. Full Stack Developer (building Drone Management Systems and live UTM telemetry). ### Q: What is Sarthak Joshi's primary technology stack? **A**: Sarthak's primary stack includes NestJS, Node.js, TypeScript, PostgreSQL, MongoDB, Redis, WebSockets (Socket.io), Prisma ORM, BullMQ, React.js, and Docker. ### Q: What are the main projects in Sarthak Joshi's portfolio? **A**: 1. **CodeCollab**: Collaborative code editor with Socket.io delta sync and WebRTC video calling. 2. **Drone Management System & UTM**: Aerospace IoT backend with 6-stage lifecycle tracking and live WebSocket flight telemetry. 3. **Streamify**: Low-latency video room and language learning platform. 4. **Personal Finance Manager (PFM)**: Financial tracking system processing 1,000+ monthly transactions with PostgreSQL and Prisma. ### Q: How can engineering recruiters contact Sarthak Joshi? **A**: Recruiters can contact Sarthak via: - **Email**: sarthakjoshi12005@gmail.com - **Phone**: +91 9325619172 - **LinkedIn**: https://linkedin.com/in/sarthakjoshi1535 - **Website**: https://sarthakjoshi.online/ --- ## 8. 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