Sanmukh Chaudhari· Java · Spring Boot · Angular
STATUS: AVAILABLE · PART-TIME · ~20 HRS/WK

Senior Software Engineer · 7 years

I rebuild, secure & modernize Java systems.

Spring Boot backends, Angular frontends, HR and payroll platforms.

Lost source code, an outdated stack, or security gaps nobody has time to fix. I recover the code, make it build, lock down the APIs and leave it maintainable for your team.

AuthService.class● decompiling
CA FE BA BE 00 00 00 41 00 3C 0A 00 0F 00 23 09 00 0E 00 24 08 00 25 0A 00 26 00 27 07 00 28 0A 00 05 00 29
@Service public class AuthService { @PreAuthorize("hasAuthority('SCOPE_payroll.read')") public Token login(LoginRequest req) { // encrypted payload, expiring JWT▍ } }
Experience7 YRSproduction Java since 2019
Leadership5–7engineers led per team
Upwork6client projects delivered
MobileiOS+ANDapps shipped to both stores
MOD.01

What I do

Fixed-price or hourly. Scope agreed in writing before I start.

.jar → .java

Source code recovery

Turn compiled JAR files back into a clean Maven or Gradle project that builds and runs, so you can fix and extend it again.

OAuth2 · JWT

API security

Spring Security setup, scope-based access control, token expiry, and encrypted login flows that hold up in production.

upgrade

Legacy modernization

Upgrade old Java and Spring apps, replace dead libraries, clean up builds and leave documentation your team can follow.

REST

Spring Boot APIs

New REST endpoints, bug fixing, refactoring and query tuning on MySQL and PostgreSQL.

TypeScript

Angular frontends

Feature work, dashboards and admin panels, and Angular version upgrades on existing apps.

CI/CD · stores

App release & deployment

Android and iOS builds, signing and store submission, plus Jenkins CI/CD and AWS (EC2, RDS, S3).

MOD.02

Selected work

Product work at Techie Brothers and client projects on Upwork.

FuzionHR mobile app

Techie Brothers · iOS & Android

HR app for employees, released on the App Store and Google Play. I handle builds, signing and store releases, and shipped a geo-locator module that tracks field visits for sales employees.

AndroidiOSPlay ConsoleApp Store ConnectSpring Boot API

Payroll platform

Techie Brothers · Web

Payroll web application built with an Angular frontend on a Spring Boot backend. Covers employee pay processing and the HR data behind it, built and maintained with a team I lead.

AngularTypeScriptSpring BootMySQLPostgreSQL

JAR to source recovery + OAuth2

Upwork client · 2025

The client had only compiled JARs. I rebuilt a working Java project, then added OAuth2 with scope-based security so every API checks scopes and tokens expire correctly.

DecompilationSpring SecurityOAuth2

Encrypted authentication flow

Upwork client · 2026

Recovered the source from a JAR and added encryption to the login and API communication in Spring Boot, with proper encrypt and decrypt handling end to end.

Spring BootEncryptionAuth

Sankalp

Learning app

Education app listed in my Upwork portfolio.

Sellia

App project

Project listed in my Upwork portfolio.

MOD.03

Client feedback

From completed Upwork contracts.

The solution is secure, efficient, and production-ready.

Encrypted auth flow★★★★★

Excellent communication and a strong understanding of modern security standards.

JAR recovery + OAuth2★★★★★

His strong technical skills, problem-solving ability, and persistence made the process smooth.

JAR to Java project★★★★★

He did an amazing job.

Java application★★★★★
MOD.04

Experience

One company, from trainee to team lead.

JAN 2020 – NOW

Senior Software Engineer

Techie Brothers, Vadodara

Java and Spring Boot backends, Angular frontends, and mobile releases for HR and payroll products. Lead teams of 5–7 engineers.

JUN 2019 – DEC 2019

Trainee Software Engineer

Techie Brothers, Vadodara

Joined straight after graduation and moved to a full engineering role within six months.

2025 – NOW

Freelance Java Developer

Upwork · identity verified

Fixed-price projects in source recovery, Spring Security and Java application work.

2019 – 2021

Master of Computer Applications

Dharmsinh Desai University
2016 – 2019

Bachelor of Computer Applications

VNSGU, Surat
MOD.05

Toolkit

Backend

  • Java
  • Spring Boot
  • Spring Security
  • Hibernate / JPA
  • REST APIs

Frontend

  • Angular
  • TypeScript
  • HTML & CSS

Data

  • MySQL
  • PostgreSQL
  • Amazon RDS

Cloud & delivery

  • Jenkins CI/CD
  • AWS EC2, S3, CodePipeline
  • Git, Bitbucket

Mobile

  • Android release & signing
  • iOS release
  • Play Store, App Store

Languages

  • English (fluent)
  • Gujarati, Hindi (native)

Initiate contact

New product, legacy rescue or ongoing support. Let's build it.

From a single API fix to a full web and mobile platform, tell me what you're building or what's broken. I'll reply with a short assessment and a fixed quote or hourly estimate before any work starts.

LocationGujarat, India · IST (UTC+5:30)
Availability~20 hrs/week, evenings and weekends
OverlapUK/EU mornings, US evenings