Backend Developer

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

Job Summary:

We are looking for a highly skilled and experienced Java Backend Developer with 4.5+ years of hands-on experience in backend development, system design, and API integration. You’ll play a key role in designing and building high-performance backend systems that are scalable, secure, and reliable. As a core member of the engineering team, you’ll collaborate closely with product owners, architects, and other developers to deliver quality solutions.

Responsibilities:

• Design and develop backend components, REST APIs, and microservices using Java and Spring Boot.
• Contribute to the architectural decisions and system design discussions.
• Write clean, efficient, and testable code following best practices.
• Optimize application performance, scalability, and reliability.
• Integrate third-party APIs and work with external systems.
• Participate in code reviews, mentor junior developers, and support the team’s technical growth.
• Work closely with DevOps to support CI/CD pipelines and deployments.
• Troubleshoot and resolve complex issues in production and non-production environments.
• Keep up with industry trends and advocate for best practices in backend development.
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Required Skills:

• 4.5+ years of hands-on experience in backend development with Java (Java 8 or above).
• Strong expertise in Spring Framework (Spring Boot, Spring MVC, Spring Data).
• Experience designing and consuming RESTful APIs and working with microservices architecture.
• Solid understanding of relational and NoSQL databases (e.g., MySQL, PostgreSQL, MongoDB).
• Proficient with version control systems like Git and tools like Maven or Gradle.
• Familiarity with Docker, containerization, and cloud platforms (AWS/GCP/Azure).
• Experience with unit testing and integration testing (JUnit, Mockito, etc.).
• Good knowledge of software design principles, data structures, and algorithms.
• Excellent problem-solving skills and attention to detail.

Job Responsibilities:

* Design, build, and maintain efficient, reusable, and reliable Java code

* Ensure the best possible performance, quality, and responsiveness of the applications

* Identify bottlenecks and bugs, and devise solutions to these problems

* Help maintain code quality, organization, and automatization

* Prepare the technical design of complex technology components

Mandatory Skills:

* Proficient in Java (JDK 1.7) or above JDK 8 preferable, with a good knowledge of its ecosystems with a knack for writing clean, readable Java code, writing reusable Java libraries along with knowledge of concurrency patterns in Java

* Solid understanding of object-oriented programming along with various design and architectural patterns

* Hands on experience with Spring, Spring Boot, JUnit

* Familiarity with concepts of MVC, Microservices, RESTful

• Design, develop, test, debug and maintain components of a feature-rich management and orchestration product
• Manage one or more project priorities and deadlines
• The programming languages are mainly Python and Java
• Understand the infrastructure details of public clouds and use DevOps best practices to implement provisioning

You'll Need:

• Strong software design and implementation skills in building infrastructure frameworks.
• Experience building and operating extensible, scalable resilient systems.
• Working knowledge of Java and Python.
• Solid understanding of basic systems operations (disk, network, etc).
• Willingness and ability to learn new languages and concepts.
• 8+ years of experience and a BS/MS degree in Computer Science -or- a related field.

Nice to have:

• Cloud infrastructure systems engineering experience.
• Experience in building control planes.
• Experience building RESTful APIs.
• Experience with containers and cluster managers like Kubernetes.
• Experience in App deployment and config management frameworks such as Ansible, Terraform, Chef, Puppet, etc.

EmptyCup is an interior design platform. Our goal is to make good interior design accessible.

To know more about our vision, checkout this https://drive.google.com/file/d/1_PBkSaHLep-QsZzRWdKMI3amc-KFe99z/view">intro presentation.

You can also checkout our https://emptycup.in/">website here to know more about the product offering.

Senior Backend Engineer (Platform) Full Time Bangalore (Potentially Remote)

What you’ll be doing:

• Design and develop core systems that will be power teams to build services and apps
• Ensure and constantly improve reliability, scalability, security and performance of core apis and infrastructure
• Be proactive in technical decision making and a sound influence in technical discussions
• Work with the product teams to help shape product direction by communicating limitations and possibilities
• Adopt and advocate best practices and guidelines in architecture, code conventions, development practice

Who we are looking for:

• 5+ years of experience building web services in Python/Go/Java, preferably in Python with excellent debugging and analytical skills
• Strong understanding of software engineering principles, computer science fundamentals - data structures, algorithms and operating systems
• Proven experience in building, deploying and maintaining highly scalable RESTful web services
• Excellent written and oral communication ability in both technical and non tech. aspects
• Good understanding of benchmarking and performance monitoring - concurrency, multi-threading, logging, database optimisations
• Decent knowledge of CI/CD pipelines and familiarity with shipping code quickly and reliably.

What we offer:

• Ownership of the platform core with a clear roadmap.
• A small cool meritocratic team that's driven by passion.
• An inspiring culture that balances creative exploration & heads down execution.
• Cash compensation upto 20L and negotiable stock in a gold mine.