Java · Spring Boot · ReactJS · Cloud

Java Backend & Full-Stack Engineer

Java-focused backend and full-stack engineer with 3.8+ years building secure healthcare and E-commerce systems on Spring Boot, ReactJS and AWS / Oracle Cloud.

I build backend‑heavy web applications that are secure, predictable, and easy to evolve. Over the last 3.8+ years I’ve worked on healthcare, MedTech, and E‑commerce systems using Java, Spring Boot, ReactJS and cloud platforms like AWS and Oracle Cloud.

Pune, Maharashtra, India · Open to Java Backend / Full‑Stack Engineer roles

Java 8/11Spring BootReactJSREST APIsAWSOracle Cloud (OCI)PostgreSQLHealthcareE‑commerce
OCI Architect CertifiedOCI Architect Certified
OCI Developer CertifiedOCI Developer Certified
MTA DeveloperMTA Developer
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Snapshot

Sagar Lahade

Java Backend & Full-Stack Engineer

Experience

3.8+ years

Focus

Backend-heavy full-stack

Domains

Healthcare · MedTech · E-commerce

Open to

Java Backend / Full-Stack

Find me on

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About Me

Backend-leaning full-stack engineer · Java / Spring Boot · React · Cloud

I enjoy taking messy, domain-heavy problems and turning them into clear, well-structured services. On some projects that meant sitting with doctors to understand diagnostic flows; on others it meant walking through payment edge cases with business teams before writing a single line of code.

I lean towards simple designs that can be explained on a whiteboard in a few minutes. Once the basics are right—data model, API boundaries, security, tests—then I worry about performance and polish.

Backend-first

Comfortable owning Java/Spring Boot services end-to-end and exposing them via clean REST APIs.

Applied in MediMart, CerviTester and HealthHub, from data model to deployment.

Cloud-aware

Design services to run on AWS and Oracle Cloud using Docker and externalised configuration.

Used for MediMart Cloud deployments on AWS (EC2, S3, RDS) and OCI compute/networking.

Quality-driven

Use tests, code reviews and static analysis to keep codebases maintainable over time.

Backed by JUnit, SonarQube, JaCoCo and Postman suites across major services.

Skills

Strongest in Java/Spring backend, comfortable in ReactJS, and confident deploying services on AWS and Oracle Cloud. Everything listed below has been used in real projects, not just tutorials.

Backend

Java 8/11coreSpring BootcoreSpring MVCREST APIscoreJPA/HibernateSpring SecuritycoreJWT / OAuth 2.0Validation & error handling

Used in: MediMart, CerviTester, HealthHub

Frontend (ReactJS)

ReactJScoreReact HooksReact Routerfetch/axios API callsHTML5, CSS3, JavaScriptResponsive layouts

Used in: MediMart UI, LahadeMart React, JobPortal

Cloud & Platform

AWS (EC2, S3, RDS basics)coreOracle Cloud (OCI compute, networking, storage, IAM)coreDockerKubernetes / OpenShift basicsMicroservices fundamentals

Used in: MediMart Cloud on AWS/OCI

Databases

PostgreSQLcoreMySQLSchema designIndexing & query optimisationTransactions

Used in: All major backend projects

Quality & Delivery

MavenGit / GitHub / BitbucketGitHub Actions / Jenkins-style CI/CDPostmanJUnitcoreSonarQubecoreJaCoCocoreAgile (Scrum), Jira

Used in: MediMart, CerviTester, HealthHub

AI / Data & Fundamentals

PythonTensorFlow integrationcoreImage-based disease detectionImage processing basicsDSA in JavaSoftware design fundamentals (MTA)

Used in: CerviTester, internships, personal learning

Experience

Java Developer

Config Server LLP · MediMart Cloud

Feb 2024 – Present

Pune, Maharashtra (Remote-first)

  • Designed and developed Spring Boot REST APIs for MediMart Cloud – a healthcare E-commerce platform for browsing medical products, carts, orders, and user workflows.
  • Implemented payment-gateway integration and secured APIs with Spring Security, JWT, and OAuth 2.0, enforcing role-based access for admin, doctor, and operations users.
  • Integrated HashiCorp Vault with Spring Boot and externalized environment config so services can run safely on AWS/OCI with secrets outside code and property files.
  • Added JUnit tests and SonarQube/JaCoCo checks for core modules, reducing regressions and making refactors safer across MediMart and legal/case-management services.
Java 11Spring BootSpring MVCREST APIsSpring Security (JWT/OAuth2)PostgreSQLEhcacheHashiCorp VaultGitJUnitSonarQubeJaCoCo

Java Developer

Polymorphism Infotech

Jun 2023 – Feb 2024

Pune, India

  • Used Maven for build automation and dependency management
  • Optimized performance and fixed critical bugs, enhancing user experience
  • Followed Agile methodologies with tools like Jira and Git for source control and task tracking
  • Integrated TensorFlow deep learning models into Java to enable real-time predictions
  • Crafted DL models on MRI brain scans to identify brain tumor regions
  • Created server-rendered UIs with Thymeleaf and collaborated with frontend teams on React/JS screens and API contracts.
  • Used Ehcache and query optimization to improve latency on read-heavy endpoints.
Java 8/11Spring BootSpring MVCJPA/HibernateREST APIsPostgreSQLMySQLThymeleafEhcacheMavenGitJira

Trainee Technical Consultant

Ohum Healthcare Solutions · HealthHub

Aug 2019 – Feb 2020

Pune, India

  • Implemented Spring MVC / Spring Boot flows for hospital-management features.
  • Used Java 8 features and PostgreSQL query tuning on hospital-scale datasets.
  • Built Thymeleaf UIs and participated in Agile ceremonies using Git.
Java 8Spring BootSpring MVCREST APIsPostgreSQLThymeleafGitAgile

Engineer Trainee

WinJit Technologies

Sep 2018 – Apr 2019

Hybrid Client Engagement

  • Engineered Java-based edge and backend components to ingest press machine telemetry over MQTT and custom industrial protocols
  • Built and hardened Spring Boot REST APIs with validation and logging to stream real-time IoT data into monitoring dashboards.
  • Implemented data-driven monitoring to optimize machine health visibility and cut productivity losses from downtime
  • Designed PostgreSQL schemas and tuned queries to keep inference latency within real-world limits.
Java 8Spring BootREST APIsPostgreSQLTensorFlow (integration)Python (ML pipeline)Git

System Design & Impact

For systems like MediMart, InfuCare, HealthHub and CerviTester, the starting point is always use cases and data: catalog, orders, billing, users, diagnostics, telemetry, and so on. Each domain becomes a Spring Boot service with its own data model and a small, consistent REST API surface.

Implementations follow a layered pattern (controller → service → repository) with strong validation at the edges, clear domain methods in the middle, and straightforward persistence logic at the bottom. Read-heavy paths get caching and pagination; write-heavy or critical flows prioritise transactional integrity, idempotency, and logging so issues are observable and easy to debug.

Design practices used in projects

  • Domain-based service separation for product, order, billing, user, telemetry, and ML inference in MediMart, InfuCare, HealthHub, and CerviTester.
  • Versioned REST APIs, pagination and filtering for lists, and consistent error envelopes across services.
  • Ehcache and tuned JPA/Hibernate queries with proper indices on read-heavy catalog, patient, and telemetry endpoints.
  • Design for failure: timeouts, defensive coding, and explicit fallback or queue-based flows where downstream systems may be slow or unavailable.
  • Security by design: JWT/OAuth 2.0, RBAC, and secret management via Vault/OCI Vault for cloud-ready deployments on AWS and OCI.

Metrics & impact (indicative)

  • • Systems in roughly the 5K–20K record range and 100–500 daily active users for MediMart, InfuCare, and HealthHub.
  • • Catalog/read APIs improved by an estimated 20–30% after adding caching and query/index tuning on key endpoints.
  • • Fewer regressions reaching staging/production after adding JUnit tests plus SonarQube/JaCoCo into the build.
  • • Manual reporting and lookups replaced with web workflows, reducing repetitive operational work for hospital/E-commerce teams.

Latency before vs after optimisation (illustration only)

Before

After

Bars are illustrative, not exact numbers; they represent the effect of caching, indexing, and simpler queries on read-heavy endpoints.

Cloud & Containers

Oracle Cloud Infrastructure

Oracle Cloud Infrastructure 2025 Architect Associate and Developer Professional. Design and implement secure, scalable architectures on OCI.

  • Compute, networking, storage and IAM.
  • Containers with OKE, Functions and API Gateway.
  • OCI Logging, Monitoring and DevOps tooling.

AWS

Comfortable deploying Spring Boot services on AWS and wiring them into CI/CD pipelines.

  • EC2 for application servers.
  • RDS (PostgreSQL/MySQL) for managed relational databases.
  • S3 + CloudFront for static React assets and images.
  • Externalised configuration and environment-specific profiles.

Containers & Platform

IBM “Introduction to Containers with Docker, Kubernetes & OpenShift”.

  • Containerising Spring Boot services with Docker.
  • Image structure, health checks and environment variables.
  • Basics of Kubernetes/OKD: pods, services, deployments.

Flagship Full-Stack Project · MediMart Cloud

MediMart Cloud is a healthcare-oriented E-commerce platform where hospitals and individuals can browse medical products, manage carts and orders and pay securely online.

Tech stack

  • ReactJS SPA for products, cart, checkout and order history.
  • Spring Boot APIs for catalog, cart, orders and users with Spring Security (JWT/OAuth 2.0) and Ehcache.
  • PostgreSQL/MySQL for relational data.
  • Containerised Spring Boot app on AWS EC2 or OCI compute; DB on RDS/OCI DB; React app on S3/OCI Object Storage + CDN.
  • Secrets managed via Vault/OCI Vault.

What it shows

  • Ability to design and ship features end-to-end: data model, API, security, UI and deployment.
  • Cloud-ready patterns like externalised config, health endpoints and useful logging.
  • Focus on security, caching, observability and tests so the system behaves well in production.

High-level architecture

  • ReactJS SPA in browser.
  • API Gateway / Load balancer.
  • Spring Boot service (catalog/cart/orders/users).
  • PostgreSQL/MySQL database.
  • Object Storage (product images, static assets).
  • Logging/monitoring in cloud-native tools.

Projects

MediMart Cloud preview
Professional

MediMart Cloud

Healthcare-focused E-commerce app where hospitals and individuals can browse products, manage carts and place orders securely.

ReactJSJavaSpring BootSpring SecurityPostgreSQL/MySQLDockerAWS/OCI
CerviTester – Screening Backend preview
Professional

CerviTester – Screening Backend

Backend for an AI-assisted cervical cancer screening system with patient and image APIs and ML-backed predictions.

Java 8Spring BootPostgreSQLTensorFlow
InfuCare – Infusion Pump Monitoring preview
Professional

InfuCare – Infusion Pump Monitoring

Telemetry APIs and reporting to detect infusion pump anomalies and generate alerts.

JavaSpring BootPostgreSQL
HealthHub – Hospital Management System preview
Professional

HealthHub – Hospital Management System

Hospital workflows for patients, doctors, appointments, billing and records with role-based access.

JavaSpring BootSpring MVCPostgreSQLThymeleaf

How I Think

Designing JWT auth in Spring Boot

Start from threats like token theft and over-privileged users, then design short-lived access tokens, refresh tokens and a clear rotation story instead of scattering checks everywhere.

These are the kinds of trade-offs I like to discuss in design reviews and interviews.

Integrating TensorFlow models from Java

Treat the ML model as a dependency with latency and failure modes: define timeouts, input/output contracts and safe fallbacks when inference is slow or unavailable.

These are the kinds of trade-offs I like to discuss in design reviews and interviews.

Running MediMart on AWS vs OCI

Map the same architecture to EC2/RDS/S3 or OCI compute/DB/Object Storage and pick based on team skills, managed services and operational effort, not just brand.

These are the kinds of trade-offs I like to discuss in design reviews and interviews.

Education & Certifications

Education

Master of Technology (M.Tech), Computer Engineering

Pimpri Chinchwad College of Engineering (PCCOE), Pune

Dec 2021 – Nov 2023 · 89%

Software Development Life Cycle (SDLC)Data AnalyticsArtificial IntelligenceMachine LearningImage ProcessingPython ProgrammingR Programming

B.Tech, Computer Engineering

D. Y. Patil Institute of Engineering & Technology, Pune

Aug 2014 – Apr 2018 · 63%

Data StructuresAlgorithmsDBMSSDLCJava ProgrammingSoftware Engineering

Professional Certifications

  • Oracle

    Oracle Cloud Infrastructure 2025 Architect Associate

    Oracle

    Verify
  • Oracle

    Oracle Cloud Infrastructure 2025 Developer Professional

    Oracle

    Verify
  • IBM / Coursera

    Introduction to Containers with Docker, Kubernetes & OpenShift

    IBM / Coursera

    Verify
  • Pantech Solutions

    Machine Learning & AI Internship (30 days)AI

    Pantech Solutions

    Verify
  • Microsoft

    MTA: Software Development Fundamentals

    Microsoft

    Verify
  • Java, Problem Solving

    HackerRank Skill Certifications

    Java, Problem Solving

    Verify

Additional learning & coursework

Spring Boot 3, Spring 6 & Hibernate – UdemyJava 8 New Features – UdemyJava DSA Course – ScalerImage Processing Onramp – MathWorks

Awards & Achievements

Academic · AI / Deep Learning

Research Excellence Award

Pimpri Chinchwad College of Engineering (PCCOE)

Received a cash award for research on deep learning–based cervical cancer detection, recognising innovation and applied AI research in healthcare.

Innovation · Sustainability

Innovation & Sustainability Project (Patent Pending)

Academic / Social Impact Project

Developed a Ganesh Idol Management System with sponsorship to mitigate water contamination risks caused by traditional immersion practices; patent filing in progress.

Algorithms · Performance

Published Research Contribution

Scopus-Indexed Research

Designed an enhanced Apriori Algorithm improving system performance by ~15%, leading to a published research paper in a peer-reviewed journal.

Industry · Architecture

Strategic Mind Award

Config Server LLP

Awarded for impactful backend architecture decisions, strong technology–business alignment, and data-driven problem solving in Java microservices.

Research Papers

Scopus

DeepCerviCancer – Deep Learning-Based Cervical Image Classification using Colposcopy and Cytology Images

EAI Endorsed Transactions on Pervasive Health and Technology

Open Paper →
Scopus

Analyze the Novel Apriori Algorithm for Frequent Pattern Generation and Improving the Performance by Generating Powersets for Unique Records

Communications in Mathematics and Applications

Open Paper →
Scopus / Springer

Tea Leaf Disease Classification Using an Encoder-Decoder Convolutional Neural Network with Skip Connections

International Conference on Image Processing and Capsule Networks (Springer)

Open Paper →

Contact

Interested in a Java/React engineer who can own the backend and work comfortably with cloud and frontend? Let’s talk.

Pune, Maharashtra, India

Email: lahade.sb@gmail.com

Phone: +91 9766180110 / +91 8381037829 / +91 9270506146