Java Developer

Key Responsibilities

• Design, develop, and maintain scalable backend applications using Java and Spring Boot.
• Develop and maintain RESTful APIs following best practices.
• Implement API versioning strategies to support backward compatibility.
• Create and maintain API documentation using Swagger/OpenAPI.
• Implement Spring Transaction Management to ensure data integrity
• Use Spring Data JPA for database interactions and ORM mapping
• Write efficient SQL queries and optimize database performance
• Implement CQRS (Command Query Responsibility Segregation) where applicable.
• Develop systems based on event-driven architecture patterns.
• Write unit tests using JUnit and Mockito.
• Build and manage projects using Maven or Gradle build scripts.
• Use AI coding assistants such as Gemini Code Assist or similar tools to improve development efficiency.
• Participate in code reviews, design discussions, and architecture decisions.
• Collaborate with frontend teams, DevOps engineers, and product stakeholders.
• Strong problem-solving and debugging abilities
• Ability to design highly scalable backend systems
• Experience working in Agile/Scrum environments
• Good communication and collaboration skills
• Strong code quality and clean architecture mindset

Optional / Good to Have Skills

• Experience with Docker
• Knowledge of Kubernetes
• Experience with GraphQL API development
• Experience with cloud platforms (GCP / AWS / Azure)

Candidates from Supply Chain , Retail preferred

About ZYSYGY

ZYSYGY is building Germany's zero-fee payment network. Merchants pay zero transaction fees. We route payments directly over SEPA Instant, bypassing Visa, Mastercard, and the entire card network chain. No hardware. No card reader. Just a phone.

We are building the first company to combine a fully software-based merchant POS with a consumer super-app for everyday financial life: payments, transport, utilities, government services, all in one place. Think what UPI did for India. We are doing it for Germany, from the ground up, on banking rails.

Role Overview

You will join the core engineering team as a founding engineer. You will own the backend payment engine end to end: transaction flows, wallet management, SEPA Instant settlement, KYB/KYC integration, recurring mandates, refund logic, and the compliance export layer (DATEV, Kassenbuch, GoBD, fiskaltrust). On mobile, you will contribute to the React Native consumer and merchant apps alongside our mobile engineer.

You will own what you build from development through deployment, monitoring, and production reliability. The architecture decisions you make in the first six months will run in production for years.

What you will do

Design and build the backend payment engine: transaction flows, wallet management, SEPA Instant settlement, offline payment authorization, and recurring mandate billing.

Own KYB/KYC integration and the compliance export layer: DATEV, Kassenbuch, GoBD, and fiskaltrust for KassenSichV.

Build REST APIs for financial-grade reliability and high-throughput transaction processing, including full R-transaction handling and reconciliation pipelines.

Contribute to the React Native consumer and merchant mobile apps alongside our mobile engineer.

Own the full lifecycle of what you build, from development through deployment, monitoring, and continuous improvement.

Integrate AI tooling into your development workflow as a matter of course: code generation, automated testing, and intelligent review.

Who you are

Meaningful hands-on experience building payment systems, fintech infrastructure, or financial APIs.

You have designed a ledger. You understand double-entry bookkeeping, immutable transaction records, and why you never update a financial row.

You have solved the partial failure. Money left one wallet and did not arrive in the other. You know how to detect it, resolve it, and make sure it does not happen again.

You understand idempotency at a design level. You have built systems that survive client retries, duplicate webhooks, and network drops without double-charging anyone.

You have built or reasoned about reconciliation: detecting discrepancies between your internal ledger and an external settlement file, and resolving them reliably at scale.

You understand KYC and KYB state machines, what happens when verification status changes mid-transaction, and what a regulator expects from your audit trail.

You are comfortable with SQL databases and own the full lifecycle of your code from development through deployment.

You can communicate technical decisions clearly to non-technical stakeholders. At this stage of the company, that matters.

You are a continuous learner. Payments infrastructure is a deep domain and you treat it that way.

You are comfortable with ambiguity and early-stage risk. There is no playbook yet. You will help write it.

Strong academic background preferred. Demonstrated engineering ability matters more than institution.

Relocation

Relocation to Munich, Germany, is on the table for the right candidate, including visa support.

Connect with the Founder

You can also connect with me on LinkedIn at www.linkedin.com/in/shabbir-maimoon

Company: Billion-dollar US-based Retail

About the Role:

We are seeking a talented and experienced Fullstack Engineer with a strong focus on frontend development to join our dynamic team. You will work with modern web technologies to design and implement highly scalable and user-friendly interfaces for our global e-commerce platform. This is a hybrid role requiring 3 days a week from the office and 2 days remote.

Key Responsibilities:

Develop and maintain high-performance web applications with a primary focus on frontend features.

Collaborate with designers, backend engineers, and product managers to deliver seamless user experiences.

Write clean, maintainable, and scalable code using React.js, Vue.js, and other modern frameworks.

Integrate and optimize backend services using Node.js and PostgreSQL.

Participate in code reviews, mentoring sessions, and team discussions to uphold engineering excellence.

Stay up-to-date with emerging trends and technologies in fullstack and frontend development.

Required Skills and Experience:

8+ years of professional experience in software development, focusing on fullstack engineering.

Strong proficiency in React.js and/or Vue.js for frontend development.

Solid understanding of Node.js for backend services.

Experience with relational databases like PostgreSQL.

Proficiency in building responsive, cross-browser-compatible, and accessible user interfaces.

Familiarity with agile development methodologies and version control systems like Git.

Excellent problem-solving skills and the ability to work effectively in a team-oriented environment.

Preferred Qualifications:

Previous experience in the retail/ E-commerce / and finance domain a plus.

We are seeking an Electron + Angular Full-Stack Developer to build and maintain cross-

platform desktop applications with strong offline-first capabilities. The ideal candidate will

have hands-on experience with Angular, Electron, and at least one backend technology, with

a focus on performance, data synchronization, and security.

Key Responsibilities

 Develop cross-platform desktop applications using Angular and Electron

 Implement offline-first architecture with seamless online/offline synchronization

 Securely store local data and sync with backend services when online

 Implement IPC communication between Electron main and renderer processes

 Design and integrate REST APIs

 Handle conflict resolution, retry mechanisms, and data integrity

 Optimize desktop UI/UX and application performance

 Ensure stability during crashes or forced shutdowns

 Apply Electron security best practices

 Collaborate with design, backend, and product teams

Required Skills

 Strong experience with Angular (latest versions)

 Hands-on experience with Electron.js (Windows, macOS, Linux)

 Proficiency in TypeScript, HTML, SCSS

 Experience with Angular Material / Bootstrap

 Good knowledge of RxJS and state management

 Backend experience with .NET Core / C# or Node.js + Express

 REST APIs, JSON handling, authentication, and role management

 Database experience: SQLite / MySQL / PostgreSQL / MongoDB

 Local file system handling for desktop applications

Must-Have Experience

 Offline and online synchronization logic

 Secure local storage using SQLite / IndexedDB / filesystem

 Auto-update handling in Electron

 Build and packaging using electron-builder / electron-forge

 Git version control

 Electron application security best practices

Nice to Have

 Experience with large-scale offline applications

 Exposure to kiosk or enterprise desktop systems

 Performance optimization and crash recovery experience

Job Description:

Technical Lead – Full Stack

Experience: 8–12 years (Strong candidates Java 50% - React 50%)

Location – Bangalore/Hyderabad

Interview Levels – 3 Rounds

Tech Stack: Java, Spring Boot, Microservices, React, SQL

Focus: Hands-on coding, solution design, team leadership, delivery ownership

Must-Have Skills (Depth)

Java (8+): Streams, concurrency, collections, JVM internals (GC), exception handling.

Spring Boot: Security, Actuator, Data/JPA, Feign/RestTemplate, validation, profiles, configuration management.

Microservices: API design, service discovery, resilience patterns (Hystrix/Resilience4j), messaging (Kafka/RabbitMQ) optional.

React: Hooks, component lifecycle, state management, error boundaries, testing (Jest/RTL).

SQL: Joins, aggregations, indexing, query optimization, transaction isolation, schema design.

Testing: JUnit/Mockito for backend; Jest/RTL/Cypress for frontend.

DevOps: Git, CI/CD, containers (Docker), familiarity with deployment environments.

Required Skills and Experience:

Proficient in Java (Java 8 and above), with a strong understanding of object-oriented programming.

Knowledge in the trading domain, including familiarity with trading systems and protocols.

Strong skills in SQL and PL/SQL for database management and query optimization.

Hands-on experience with Linux and Windows operating systems for application deployment and maintenance.

Proficiency in scripting languages (e.g., Bash, PowerShell, or similar).

Knowledge of Python programming for auxiliary development and analytics tasks.

Familiarity with multithreading, concurrency, and low-latency application development.

Experience with CI/CD pipelines, version control systems (e.g., Git), and deployment workflows.