Backend Engineer with 9 months of software engineering experience (currently architecting high-concurrency crypto copy-trading engines and previously delivered client compliance portals ). Specializing in Java 17, Spring Boot 3.3, and Spring Cloud Microservices — designing resilient distributed systems, client-side load balancing, thread pools, pessimistic concurrency control, and cryptographically verified financial ledgers.

• 🎯 Core Expertise: Spring Cloud Microservices (Eureka, API Gateway, LoadBalancer, OpenFeign, Resilience4j), High-Throughput REST APIs, Multithreading & Concurrency, Pessimistic Locking (SELECT FOR UPDATE), Redis Caching, PostgreSQL, Docker & Linux VPS.
• 🔭 Current Role: Backend Developer — high-concurrency trading & multi-wallet ledger platforms.
• 🌱 Currently Deepening: Apache Kafka for distributed event streaming and Saga pattern for distributed transactions.
• 👨💻 Portfolio: ankitgurjar.netlify.app
• 📄 Resume: View Latest Resume
• 📫 Contact: ankitdoi82@gmail.com

An enterprise-grade, distributed healthcare architecture migrated from a high-throughput modular monolith into a resilient Spring Cloud microservices ecosystem.

• 🌐 Service Registry & Discovery: Implemented Netflix Eureka Server (port: 8761) enabling dynamic zero-hardcoding service registration and self-healing health tracking via 30s heartbeats.
• 🚪 API Gateway & Routing: Configured Spring Cloud Gateway (port: 8080) built on reactive Netty/WebFlux as the single ingress point, managing route predicates, security token relay, and global CORS policies.
• ⚖️ Client-Side Load Balancing: Integrated Spring Cloud LoadBalancer operating within Gateway and OpenFeign clients, distributing traffic across multi-replica service instances using Round-Robin scheduling.
• 🔗 Declarative Inter-Service RPC: Built clean inter-service communication using Spring Cloud OpenFeign — decoupling downstream endpoints and resolving dynamic URLs via Eureka.
• 🛡️ Fault Tolerance & Circuit Breaking: Guarded remote service invocations with Resilience4j Circuit Breakers, automatically tripping on failure spikes (CLOSED ➔ OPEN ➔ HALF-OPEN) with graceful UserClientFallback mechanisms to prevent cascading crashes.
• 🗄️ Database-per-Service Decoupling: Migrated tightly-coupled monolithic @ManyToOne cross-boundary JPA relationships to discrete numeric foreign keys (patientId, doctorId), preserving boundary integrity across independent schemas.
• 🔐 Enterprise Security: Stateless JWT authentication with server-side token revocation via Redis Blacklisting, Google OAuth2 integration, and role-based access control (Admin, Doctor, Patient).
• 💳 Cryptographic Payment Integrity: End-to-end Razorpay gateway integration with server-side HMAC-SHA256 signature verification ensuring zero-tamper financial transactions.
• 🤖 AI Health Assistant: Guardrailed medical chatbot powered by Groq LLM (Llama 3.3) with strict prompt boundaries and 503 circuit-breaker fallbacks.
• 🐳 Containerized Deployment: Multi-stage Dockerized build orchestrated with Docker Compose (Spring Boot + MySQL + Redis) deployed to a Hostinger VPS.

🔗 Code Repositories: Backend Repo (with Microservices Suite) · Frontend Repo (React 19) · Architecture Guide

🗓️ Jul 2026 – Present | 📍 Jaipur, Rajasthan
Java 17 · Spring Boot 3.3 · PostgreSQL · Web3j (BSC/BEP-20) · Binance Futures API · Concurrency / Thread Pools · Flyway · Docker

• Sole Backend Architect (Crypto Copy-Trading): Built the complete backend for a high-concurrency crypto copy-trading & multi-wallet platform (Spring Boot 3.3, Java 17, PostgreSQL) integrating with Binance Futures and an external AI signal engine.
• ~55% Latency Reduction (1.9s ➔ 0.85s): Slashed order execution latency by ~55% (verified via application logs) by eliminating redundant per-order leverage/hedge-mode API calls and persisting them at the exchange account level.
• Financial Ledger & Anti-Double-Debit Engine: Engineered a multi-wallet ledger and withdrawal flow utilizing PostgreSQL pessimistic locking (SELECT ... FOR UPDATE), idempotency keys, and before/after balance audit logs to prevent duplicate debits under concurrent requests.
• On-Chain Blockchain Verification (Web3j): Integrated Web3j to verify on-chain BEP-20 USDT transactions on Binance Smart Chain (tx hash, recipient, amount) before wallet debits, enforcing unique transaction hash constraints to prevent replay attacks.
• Non-Blocking Asynchronous Trade Fan-Out: Implemented event-driven trade propagation using @TransactionalEventListener(AFTER_COMMIT) paired with dedicated thread pools and explicit rejection policies, preventing slow exchange network calls from blocking the live price-feed thread.
• Pluggable Exchange Strategy: Designed an extensible Strategy/Registry pattern supporting Binance, Bybit, and BingX; secured stored user API keys using AES-256-GCM encryption.
• Recursive Hierarchies & Schema Evolution: Authored native PostgreSQL recursive CTEs for binary-tree placement and upline trading volume propagation; managed database lifecycle across 60+ Flyway migrations.
• Production VPS Deployment: Containerized the backend service and PostgreSQL with Docker behind an Nginx reverse proxy with SSL termination on a Linux VPS.

🗓️ Dec 2025 – Feb 2026 | 📍 Jaipur, Rajasthan
Spring Boot · Angular · MySQL · Blob Serialization · Payment Gateways · REST APIs

• CA Compliance Portals: Developed and deployed 3 full-stack CA-firm portals (Spring Boot + Angular) handling automated tax computation and GST filing workflows.
• Stream Serialization & Storage: Engineered multi-file upload pipelines with backend file storage and binary stream serialization.
• Production Debugging: Diagnosed and resolved 10+ critical production issues across form data mapping, blob serialization, file-handling APIs, and date format synchronization.