Backend Developer

Role

We are looking for a Full Stack Engineer who can own the entire technical stack, design systems that scale, and ship products fast. You will work across frontend, backend, and AI systems, making key architectural decisions while building a product used by real users.

This role offers high ownership, where engineers move ideas to production quickly and take responsibility for both technical decisions and product impact.

What would you do?

• Build and own the end-to-end platform using React, Node.js microservices, Python AI agents, and AWS.
• Design and implement scalable system architecture, including caching, databases, and state management between AI and UI.
• Develop AI-powered backend services and orchestrate LLM workflows using modern frameworks.
• Build highly interactive front-end experiences using modern React and real-time communication tools.
• Define and maintain engineering best practices, including CI/CD pipelines, monorepo structures, and development workflows.
• Collaborate closely with users and product teams to identify problems and ship impactful solutions.
• Continuously simplify systems by removing unnecessary complexity and keeping architecture clean.

Who should apply?

• Engineers with 4+ years of experience building and shipping production-grade products.
• Strong understanding of system design, architecture, and scalable backend systems.
• Hands-on experience with Python (FastAPI, async systems) and LLM-based applications.
• Proficiency in JavaScript / TypeScript with Node.js and modern backend frameworks.
• Experience building modern frontend applications using React (React 18+).
• Familiarity with databases such as Redis, PostgreSQL, or MongoDB, and designing scalable APIs.
• Engineers comfortable working in fast-paced environments with high ownership and minimal process overhead.

Technical Skills

• Backend: Node.js, Express, Python, FastAPI
• Frontend: React (React 18+), interactive UI development
• AI/LLM Systems: LLM orchestration, multi-model integrations
• Databases: Redis, PostgreSQL, MongoDB
• Infrastructure: AWS, CI/CD pipelines, microservices architecture
• Real-time Systems: Socket.IO, Server-Sent Events (SSE)

• Experience in Python
• Experience in any Framework like Django, and Flask.
• Primary and Secondary skills - Python, OOPs and Data Structure
• Good understanding of Rest Api 
• Familiarity with event-driven programming in Python 
• Good analytical and troubleshooting skills

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

About Our Client

It is a last-mile tech-logistics solution provider for intra-state deliveries based in Bangalore. It offers reliable, affordable, and professional services, structured to serve enterprises.

Our Client aggregates light commercial vehicles for urban logistics and has onboarded 55,000+ truckers on its platform across 14 cities. Our Client works across industry sectors like organized retail, FMCG and e-commerce, distribution and 3PL companies. Some of its clients include Amazon, Flipkart, Bisleri, Vishal Mega Mart, Future Supply Chain, Coca-Cola, Delhivery, and Udaan.

The company offers customized logistics solutions for clients, along with other value-added services such as screened drivers, audited and GPS-enabled vehicles, point-to-point billing, status updates, 24x7 service, and greater efficiency, all at transparent and economical pricing.

Our Client, as a brand, is known as one of the market leaders in the enterprise segment, and first movers to identify and empathize with the underserved urban trucker community, playing a huge role in making them a part of the mainstream economy. This series-B funded tech-logistics company aims to disrupt the primitive $35bn+ urban-logistics industry by leveraging technology and help enterprises to reach consumers faster.

Our Client is India's largest enterprise urban-logistics provider in India, with 55,000+ Light Commercial Vehicles on its platform.

Why Our Client?

1) Young Startup growing and well funded.

What will I do?

- Designing user flows and converting them into logical entities in the code.

- Integration of user-facing elements developed by front-end developers with server-side logic.

- Designing Database schemas.

- Building reusable code and libraries for future use

- Optimization of the application for maximum speed and scalability

- Implementation of security and data protection

- Design and implementation of data storage solutions

What skills should I have?

- 3+ years of experience in Backend Development.
- Language: NodeJs
- Additional knowledge of Python will be a plus
- Understanding of microservices architecture.
- User authentication and authorization between multiple systems, servers, and environments
- Integration of multiple data sources and databases into one system

- Management of hosting environment, including database administration and scaling an application to support load changes

- Data migration, transformation, and scripting

- Understanding differences between multiple delivery platforms such as mobile vs desktop, and optimizing output to match the specific platform
- Creating database schemas that represent and support business processes
- Implementing automated testing platforms and unit tests
- Proficient understanding of code versioning tools, such as Git

Key Skills Required :

1. Proficiency in Python 3.x based web and backend development
2. Solid understanding of Python concepts
3. Strong experience in building web applications using Django
4. Experience building REST APIs using DRF or Flask
5. Experience with some form of Machine Learning (ML)
6. Experience in using libraries such as Numpy and Pandas
7. Hands on experience with RDBMS such as Postgres or MySQL including querying
8. Comfort with Git repositories, branching and deployment using Git
9. Working experience with Docker
10. Basic working knowledge of ReactJs
11. Experience in deploying Django applications to AWS,Digital Ocean or Heroku

Responsibilities :

1. Understanding requirement and congributing to engineering solutions at a conceptual stage to provide the best possible solution to the task/challenge
2. Building high quality code using coding standards based on the SRS/Documentation
3. Building component based, maintainable, scalable and reusable backend libraries/modules.
4. Building & documenting scalable APIs on the Open Spec standard
5. Unit testing development modules and APIs
6. Conducting code reviews to ensure that the highest quality standard are maintained
7. Securing backend applications and APIs using industry best practices
8. Troubleshooting issues and fixing bugs raised by the QA team efficiently.
9. Optimizing code
10. Building and deploying the applications