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

As a Node.js Developer, you will be responsible for:

Designing, developing, and maintaining server-side applications and systems using Node.js, a JavaScript runtime environment. Your expertise in backend development, JavaScript, TypeScript, and REST APIs will play an essential role in creating efficient and powerful server-side applications.

Responsibilities:

● Design and implement efficient, secure, and maintainable server-side code using Node.js.

● Collaborate with the front-end development team to integrate user-facing elements with server-side logic.

● Develop APIs for seamless data flow between the front-end and back-end.

● Optimize application performance and ensure high availability and scalability.

To succeed in this role – you should have the following:

● Minimum of 3-4 years of experience as a backend developer.

● Must have proven experience as a Back-End Developer, with a focus on Node.js.

● Proficiency in JavaScript, TypeScript, and related frameworks (Express.js, Hapi.js, etc.).

● Experience with RESTful API design principles.

● Experience with agile development methodologies.

● Familiarity with working with at least one of PostgreSQL or MongoDB.

● Familiarity with version control systems (Git)

● Strong communication skills and ability to work collaboratively in a team.

● Strong problem-solving skills and attention to detail.

Added bonus:

● Familiarity with frontend development technologies like HTML and CSS.

● Experience working with Docker, Github Actions, and other common CI/CD pipelines

● Knowledge about AWS components (S3, EC2, Cloudfront, Redis Clusters, etc.)

Education:

Bachelor's degree in Computer Science, Information Technology, or a related field

• Bachelor's or Master’s degree in Computer Science or equivalent area
• 10 to 20 years of experience in software development
• Hands-on experience designing and building B2B or B2C products
• 3+ years architecting SaaS/Web based customer facing products, leading engineering teams as software/technical architect
• Experiences of engineering practices such as code refactoring, microservices, design and enterprise integration patterns, test and design-driven development, continuous integration, building highly scalable applications, application and infrastructure security
• Strong cloud infrastructure experience with AWS and/or Azure
• Experience building event driven systems and working with message queues/topics
• Broad working experience across multiple programming languages and frameworks with in-depth experience in one or more of the following: .Net, Java, Scala or Go-lang
• Hands-on experience with relational databases like SQL Server, PostgreSQL and document stores like Elasticsearch or MongoDB
• Hands-on experience with Big Data processing technologies like Hadoop/Spark is a plus
• Hands-on experience with container technologies like Docker, Kubernetes
• Knowledge of Agile software development process

Fusion Softtech is one of the best offshore development companies based in Ahmedabad, India. We are a bunch of tech-savvy individuals who together as a teamwork to have great expertise in the latest technologies and developments so as to be able to cater the best of the services in the domain of Technology.

We, ensure being the hard core Technoids that our clients around the globe are given the best of our facilities through advancements in technologies which would actually help to make their lives a better place. What we do? We are specialized in creating user-friendly web-designs and applications with a primary goal to be simple and effective for use. We work hand-in-hand with your visions and goals to optimize your business/product. We provide you an end-to-end solution.

• Lead a team, handle client, conduct technical interview, and provide training to new joiners.
• Design, implement, and maintain web application phases.
• Conduct software analysis, programming, testing, and debugging
• Identifying production and non-production application issues
• Transforming requirements into stipulations.
• Should have knowledge of Data structures
• Develop, test, implement and maintain application software
• Recommend changes to improve established software application processes
• Ability to develop logical and high-quality code which meets functional specifications along with technical requirements for reusability, maintainability and scalability when appropriate application code for java programs.
• Ability to perform technical analysis based on requirements to establish architecture approach and create detailed design in support of the requirements.
• Excellent written and verbal communication skills, worked for foreign client would be an added advantage.

Technical Skills:
OOPS, Java, J2EE, Spring MVC, Spring Boot , Spring security and Spring Batch SOAP, REST API, Logging Framework, Hibernate, XML, JEE (Servlets/JSP/JMS), web services experience, microservices, AWS, Kubernetes, ELK Stack, Multithreading, GIT

Key Skills and Experience:

• Min 5+ years of experience in the JAVA/J2EE.
• Experience with RESTFUL Web services.
• Experience in portal & web content management
• Hands-on experience on Javascript frameworks Alloy UI and JQuery.
• Hands-on experience in software development using J2EE Frameworks Spring, Spring Boot, Struts, Hibernate.
• Basic knowledge of Javascript, HTML5, and CSS3.
• Good to have experience or Knowledge in AngularJS, ReactJS, different AWS services like S3, EC2, DynamoDB, Lambda function.
• Exposure in any of the Databases -MySQL/Postgres/Oracle/DB2 etc.

Perks and Benefits:

• Flexible working hours.
• 5 days working
• Fun loving environment with ample scope for flexibility.
• Exposure to work for foreign clients
• Employee friendly leave & Company Policies.
• Best working culture

Come and Join the future.

This is an opportunity to work directly with Industry experts having 20+ years of experience in Technology and product development.

Roles and Responsibilities 

• Developing front end website architecture.
• Designing user interactions on web pages.
• Developing back end website applications.
• Creating servers and databases for functionality.
• Ensuring cross-platform optimization for mobile phones.
• Ensuring responsiveness of applications.
• Working alongside graphic designers for web design features.
• Seeing through a project from conception to finished product.
• Designing and developing APIs.
• Meeting both technical and consumer needs.
• Staying abreast of developments in web applications

Desired Candidate Profile

• Strong organizational and project management skills.
• Proficiency with fundamental front end languages such as HTML, CSS and JavaScript.
• Familiarity with JavaScript frameworks such as Angular JS, and React JS.
• Proficiency with server-side languages like Nodejs, and Expressjs.
• Familiarity with database technology such as MySQL, Postgresql or MongoDB.
• Excellent verbal communication skills.
• Good problem-solving skills.
• Attention to detail.

Responsibilities:

• Writes high quality code & unit tests, builds, tests as per agreed timelines
• Participates in technical design and provides estimation
• Owns one or more small to medium features
• Becomes a go-to person in at least one area
• Communicates clearly and gets clarification upfront to minimize rework. Knows when to ask for help to unblock.
• Consistently follows and promotes SDLC best practices: Coding standard, testing, code reviews, code comments etc.
• Exhibit strong problem solving skills, helps other developers and demonstrates teamwork

Requirements:

• Understands detailed requirements and demonstrates excellent problem solving skills
• Deep understanding of software engineering practices, Design Patterns, Data Structures, Algorithms
• Excellent programming skills in ROR, Golang, NodeJS, Python
• Strong communication skills
• Strong sense of ownership, drive and ability to deliver results
• 4+ years of experience in product driven organization
• A Bachelors or Masters degree in engineering from a reputed institute
• Experience in Golang, RoR, Unity, ML or Python will be an added advantage