Backend Developer intern

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 the Role

We are seeking a highly skilled and motivated Senior Backend Developer with strong expertise in Node.js and AWS to join our dynamic team. The ideal candidate will have solid backend development experience, with additional working knowledge of PHP and Python. Exposure to frontend frameworks like React.js and Angular will be considered a strong advantage.

Key Responsibilities

• Design, develop, and maintain scalable backend systems and APIs using Node.js.

• Deploy, manage, and optimize applications on AWS cloud infrastructure.

• Collaborate with cross-functional teams (frontend, product, QA) to deliver end-to-end solutions.

• Ensure application performance, security, and scalability.

• Write clean, maintainable, and testable code following industry best practices.

• Work with databases (SQL/NoSQL) to design efficient data models and queries.

• Integrate third-party services and APIs when required.

• Contribute to code reviews, technical discussions, and mentoring of junior developers.

• Support continuous integration and deployment pipelines.

• Troubleshoot, debug, and optimize existing applications.

Requirements

• 4+ years of backend development experience.

• Strong expertise in Node.js and hands-on experience with AWS services (EC2, S3, Lambda, etc.).

• Good working knowledge of PHP and Python.

• Strong understanding of RESTful API design, microservices architecture, and databases (MySQL, PostgreSQL, or MongoDB).

• Working knowledge of React.js and Angular is preferred.

We're seeking passionate, next-gen minded engineers who are excited about solving complex technical challenges and building innovative, first-of-its-kind products which make a tangible difference for our customers. As a Backend SDE-1, you will play a key role in driving strategic initiatives, collaborating with cross-functional teams across business, product, and operations to solve exciting problems. This role demands strong technical acumen, leadership capabilities, and a mindset focused on innovation and operational excellence.

We value individuals who think independently, challenge the status quo, and bring creativity and curiosity to the table—not those who simply follow instructions. If you're passionate about solving problems and making an impact, we'd love to hear from you.

Key Responsibilities

• Strategic Planning: Work closely with senior leadership to develop and implement engineering strategies that support business objectives. Understand broader organization goals and constantly prioritise your own work.
• Technical Excellence: Understand the onground problems, explore and design various possible solutions to conclude and implement scalable, extensible and secure software systems. Implement and learn best practices in technical architecture, coding standards, and software testing to ensure product delivery with highest speed AND quality.
• Project and Program Management: Setting up aggressive as well as realistic timelines with all the stakeholders, ensure the successful delivery of engineering projects as per the defined timelines with best quality standards ensuring budget constraints are met. Use agile methodologies to manage the development process and resolve bottlenecks.
• Cross-functional collaboration: Collaborate with Product Managers, Design, Business, and Operations teams to define project requirements and deliverables. Ensure the smooth integration of engineering efforts across the organization.
• Risk Management: Anticipate and mitigate technical risks and roadblocks. Proactively identify areas of technical debt and drive initiatives to reduce it.

Required Qualifications

• Bachelor's or Master's degree in Computer Science, Information Technology, or a related field.
• 1+ years of experience in software engineering
• Excellent problem-solving skills, with the ability to diagnose and resolve complex technical challenges.
• Strong understanding of software design principles and patterns.
• Hands on with multiple programming languages and modern development frameworks.
• Understanding of relational and non-relational databases.
• Experience with Redis, ElasticSearch.
• Strong communication and interpersonal skills, with the ability to influence and inspire teams and stakeholders at all levels.

Skills:- MySQL, Python, Django, AWS, NoSQL, Kafka, Redis, ElasticSearch

Node.js Developer Responsibilities:

• Developing and maintaining all server-side network components.
• Ensuring optimal performance of the central database and responsiveness to front-end requests.
• Collaborating with front-end developers on the integration of elements.
• Designing customer-facing UI and back-end services for various business processes.
• Developing high-performance applications by writing testable, reusable, and efficient code.
• Implementing effective security protocols, data protection measures, and storage solutions.
• Running diagnostic tests, repairing defects, and providing technical support.
• Documenting Node.js processes, including database schemas, as well as preparing reports.
• Recommending and implementing improvements to processes and technologies.
• Keeping informed of advancements in the field of Node.js development.

Node.js Developer Requirements:

• Bachelor's degree in computer science, information science, or similar.
• At least 4 years' experience as a Node.js developer.
• Extensive knowledge of JavaScript, web stacks, libraries, and frameworks.
• Knowledge of front-end technologies such as HTML5 and CSS3.
• Superb interpersonal, communication, and collaboration skills.
• Exceptional analytical and problem-solving aptitude.
• Great organizational and time management skills.
• Availability to resolve urgent web application issues outside of business hours.

About us:
Equal parts creative agency, engineering firm, and consultancy, Grappus has a reputation of doing things differently. We work with brands big and small, far and wide, helping them understand, prototype and deploy a broad range of custom tech. We value design and we cringe at bad UX. Each project is a clean slate, we don’t have frameworks, or any pre-made formulas. We’re not here to just grow big, make money and win awards. We’re here to crack the process of building truly innovative products from scratch. Products that make people say ‘damn’.

People at Grappus usually experience a highly accelerated career growth well beyond the narrow constraints of their ‘job description’. Here, the growth ladder is tailored to you. It operates exactly as fast as you can manage to grow. We think it's a waste when smart people are unable to make an impact. Our aim is to unleash your potential by giving you massive challenges and the freedom to solve them.

We’re in a fluid world, where we don’t know what technologies we’ll use next, or the projects we’ll work on. We’re actively searching for ways to shine a light on our blind spots, whether it is in the products we want to build, the problems we like to solve, or the company culture we try to create. That’s what makes life at Grappus so exciting. Grappus is an ongoing experiment and you are a part of it. We'll be a different company a few years from now because you are going to change it for the better. We can’t wait to see where you take us.

About the role:
We are seeking a Senior Backend Developer who has a knack for coming up with creative solutions to unique problems, planning development cycles and writing technical documentation while leading a team of developers. You should have experience with different design pattern implementation and be quick in making architectural decisions. You can get in where needed to write clean, reusable, and performant code, with creative sensibilities to push projects towards perfection. You should have good time management skills and be able to work both autonomously and collaboratively with a cross-discipline team of product managers, strategists, UX designers, art directors, and developers.

What we’d like to see:
● Ability to write elegant and readable code
● Excellent problem solving skills and love technical challenges
● Comfortable working in a team-oriented and collaborative environment
● Strong understanding of Agile and Lean software development processes and practices
● Stays plugged into emerging technologies/industry trends and applies them proactively
● Taking leads on projects as needed
● Knowledge of software best practices, like test driven development and continuous integration
● Directing the development team in the design, development, coding, testing and debugging of applications

Must have:
● BE/ BTech in Computer Science or a related field or equivalent practical experience
● 4+ years of professional backend development experience
● Experience coaching and mentoring junior developers
● Aggressive problem diagnosis and creative problem solving skills and client handling      skills
● Ability to work and thrive in a fast-paced environment, learn rapidly and master diverse web technologies and techniques
● Experience working with Python/Django or NodeJS
● Knowledge of DRF, Redis, Celery, RabbitMQ, Jenkins, MongoDB and PostgreSQL
● Implemented CI/CD in any of the projects done
● Strong understanding of the full web technology stack (i.e. HTTP, caching, headers, cookies, etc)
● Proficiency in working with API’s and third party integrations
● Demonstrated ability to learn new technologies
● Experience with multi-tenant architectures (SaaS)
● Experience with Test Driven Development
● Excellent project and time management skills

Nice to have:
● Familiarity and experience using a variety of architectural Design Patterns
● Knowledge of Kubernetes/Docker and Devops
● Personal projects or contributions to the open source community
● Strong organizational skills to juggle multiple tasks within the constraints of timelines
● Team player (those great personality types that people love to work with)
● Great communication skills

Why you’ll love it here:
(Besides working with our team with infinite charm)

● We have no fixed work timings or leave policy, you can take unlimited leaves and start your day whenever you want. (Just make sure others in your team don’t suffer)
● We don’t track these hours you put in or ask you to fill time sheets. We don’t believe in
micromanaging, if you’re struggling, ask for help. If someone else is, offer some support.
● We never mind if people make mistakes or screw up in any way, and offer full encouragement to help people learn fast by failing fast.
● We always encourage people to be completely candid, raise alarms, or log complaints
anonymously in our feedback tool, no matter how harsh.
● We are a ‘Work from Anywhere’ company, since passionate, driven people can work from
anywhere they want; their homes, or cafes, or mountains, or beaches, anywhere.
● We have a 15-day notice period. We want to build a place where people work willingly and passionately.

Experience: 2.5 to 4 years

Location: Pune

About Studily: Optimizing education through personalized learning, Studily is here to empower educators and indulge learners across the globe. Studily uses the Flipped Learning Model to create a student-centric tool that applies artificial intelligence technology to prepare today's schooling system for tomorrow's Education Revolution.

Qualifications

• 2+ years' of experience in web development using NodeJs technologies.
• B.E., B. Tech., Msc IT, MCA etc in Software engineering/ Information technology.

Responsibilities

• Write reusable, testable, and efficient code following best practices (unit testing, source control, continuous integration, automation, design patterns, etc)
• Debug and refactoring of existing code, troubleshoot problems
• Collaborate with other developers, testers and other leads to enhance to quality product enhancements
• Take full responsibility for the quality of the code and test cases that are developed.
• Integration of user-facing elements developed by front-end developers with server-side logic.
• Provide task estimations and deliver quality code on time.
• Participate in architectural, design, and product sessions.
• Interact with different stakeholders to gather feedback and clarification.
• Research and apply new technologies and best practices.
• Should enjoy the experience of mentoring new hires on technical and process areas.
• Must have hands-on experience in building Microservices based software architecture. Must have Unix /Docker /Kubernetes /NOSQL experience

Requirements

• Knowledge of ReactJS is preferable.
• Extensive knowledge of JavaScript.
• Thorough understanding of databases such as MySQL, MongoDB or similar technologies
• In depth knowledge of working with Git.
• Experience with Restful APIs, Postman etc.
• Understanding of AWS/EC2, or other cloud services.
• Object-oriented application building experience in a professional Agile/Scrum environment. 
• Good to have Unix /Docker/Kubernetes/NOSQL experience.

Skills

• Node.js
• AWS services
• Deployment 
• Unix /Docker/Kubernetes/NOSQL

Architectural:

Design and implement a software architecture

Select a technology stack

Design and configure infrastructure

Select a development toolkit (IDE, etc.)

Design and implement a database design

Improve and optimise the application architecture

Ensure scalability of the application

Ensure scalability of the infrastructure

Explore new technologies and decide whether to implement them

Strategy, planning, and design:

• Take end-to-end ownership of the product, identify technology requirements, define the future product vision, create preliminary design concepts for add-on modules and shape overall technology and product roadmap by collaborating with the founders, business development, and marketing team.
• Ensure user oriented design is the primary approach to product development across multiple screens, based on user behaviour data and direct customer feedback.

Implementation and deployment:

• Manage Product Release, QA cycles, feature implementation and on time delivery through in-house team and vendors.
• Collaborate with team and customers to define use cases.
• Creation of wireframes/prototypes, site maps and user-flows for web and mobile platforms.

Operational management :

• Support marketing by implementing technical requirements for SEO/product analytics.
• Establish and supervise a quality assurance process, including integration & system testing.
• Rigorously monitor key performance metrics and coordinate with various teams to take corrective actions if needed.
• Establish and forecast ROI of features and succinctly articulate competitive advantage.
• Set-up data collection and analysis system in collaboration with CEO to track key performance.

metrics.

Strong fundamentals in computer science/engineering and algorithm design.

Practical knowledge of computer software algorithms in machine/deep learning, NLP, Computer Vision etc.

Personal Requirements:

• Min of 7+ years of Hands on experience in Web app development, payment gateways implementation, architecture design, product management, databases and UI/UX in consumer facing applications.
• Experience on projects involving engineering and algorithmic functions, machine learning, deep learning and artificial intelligence is very advantageous.
• Creative self-starter who is comfortable with both taking initiative and working in teams.
• Strong communication skills.
• Willingness to learn and utilise emerging technologies.
• Sincere passion to use disruptive technologies that can be globally significant

• Strong experience in Java Development
• Deep expertise and hands-on experience with Web Applications
• Experience in programming languages such as HTML, CSS, JavaScript, JQuery, React JS, and API.
• Expertise in Java, Spring Boot is an added advantage.
• Hands-on design experience with Web Services (REST, SOAP, etc ..).
• Strong grasp of security principles.

Abilities:

• Developer with  strong ability to develop web application using Java and ReactJS
• Should be able to code, design, and implement
• Maintain code integrity and organization

• 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 or Java
• Strong communication skills
• Strong sense of ownership, drive and ability to deliver results
• 2+ years of experience in product driven organization