PostgreSQL developers

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 Title: Backend Developer

Job Description: We are seeking a skilled Backend Developer to join our dynamic team. The ideal candidate will be responsible for designing, implementing, and maintaining the server-side logic, databases, and APIs of our applications. Key responsibilities include collaborating with cross-functional teams to develop scalable and efficient backend systems, troubleshooting and resolving issues, and staying updated on industry trends. Proficiency in programming languages such as Python, Java, or Node.js, along with experience in database management and API development, are essential for success in this role. Strong problem-solving skills, attention to detail, and a passion for creating robust and high-performance backend solutions are highly valued.

Requirements:

Proficiency in one or more backend programming languages (e.g., Python, Java, Node.js)

Experience with database management systems (e.g., MySQL, PostgreSQL, MongoDB)

Knowledge of RESTful API design and development

Familiarity with cloud services (e.g., AWS, Azure) is a plus

Strong problem-solving and troubleshooting skills

Collaborative mindset with excellent communication skills

Ability to work in a fast-paced and dynamic environment

JOB RESPONSIBILITIES (About 10 - 11 years and at least 9 years relevant experience)

Develop Java webservices and components according to a detailed design document.

Build efficient, reusable and reliable Java code per industry best practices.

Follow TDD approach and ensure unit-test coverage meets quality requirements.

Develop Integration tests to ensure coding adheres to acceptance criteria and verify end-to-end behavior of the system.

Ensure best possible performance, quality and responsiveness of applications.

EXPERIENCE / SKILLS

Must have experience developing in Java latest version (least version is 8)

Must have experience in design and development using Micro service architecture

Solid knowledge in OOP concepts, and design principles/patterns for developing scalable applications

Must have experience developing Spring Boot applications

Must have experience developing database access layer using Spring Data JPA/Hibernates

Must have experience in developing REST Services using Spring

Good working experience in development of event driven systems using any framework

Must have experience with any RDBMS and at least one NoSQL database preferably PostgresSQL and Mongo DB

Must have experience writing unit and integration tests using Junit

Must have experience using mock frameworks like Mockito, WireMock

Must have experience using Git

Must have experience with CI / CD

Basic hands-on experience in one of the cloud provider (AWS/Azure) or at least docker and Kubernetes

Familiarity with build tools Maven or Gradle

Added advantage with experience of Reactive and Functional Programming

HBOX is a US Based Digital Health Company, Enabling Primary Care Providers (PCP) to

capture true Virtual Care Opportunities beyond Telehealth. We enable PCP to

provide Proactive and Continuous Care and add new Recurring monthly revenue

streams without any upfront cost. With our unique distribution and business

model, we are seeing fast acceptance and great adaption with our target

customers. We have built unique and Industry's first Integrated

Hardware, Cloud & AI Technologies based Virtual care Platform for PCP

Market. We are US focused Post revenue company with customers in 7 US States

and growing extremely fast.

We want a techie at heart. Someone who is happy and curious to work on all aspects of software development. Reporting directly to the CTO, you will be responsible for feature design, development, and continuously optimizing our tech stack.

We are looking for an experienced software engineer with at least 5 years of experience in a startup or product environment. Ideally you have been involved in all aspects of software development from requirements gathering to design, development, deployment and post-release support. We are looking for all-round technical maturity. Our tech stack is Angular, Spring boot and Django/Python.

Key Skills

Java SpringBoot, PostgreSQL/MySQL, Git

AWS, REST api design, Experience integrating with external APIs

Good applied understanding of Object Oriented Programming

Good database modeling and SQL knowledge.

Anticipate how code will perform under production conditions

Understand the performance characteristics of commonly used data structures (maps, lists etc). (Optional) Experience with UI frameworks like: AngularJS/React is a big plus.

Responsibilities and Duties

Build out features across the stack: backend, API design and integration, database optimization, microservices, plugins, queues etc

Fix bugs and write automated tests

Maintain and upgrade our Tech Stack

Translate requirements to design and write/present articulate software design.

Purpose

We are looking for Sr. Laravel Developer. The candidate must have Good level of proficiency in PHP, MySQL, object-oriented JavaScript, HTML5, CSS3, AJAX, XML, JSON required and Write clean PHP code in a timely and scalable way.

Key Responsibilities

• Responsible to Code, Test, Deploy and Scale SaaS-based Products using PHP, MySQL, with Laravel and Lumen MVC framework.
• Can write functional requirement documents and guides others within the project / team.
• Develop, write and implement software programming applications following established architecture standards as well as software development and project management methodologies.
• Integrate / Develop to third-party APIs.
• Write high quality code using the guidelines and effectively debug the code; perform code review of junior members.
• Azure or Aws cloud knowledge is good to have.
• Proficient understanding of code versioning tools, such as SVN, GIT.
• Build and implement web applications and back-end services that integrate with mobile applications.
• Build reusable code and libraries for future use & Optimize application for maximum speed and scalability.
  
  

Skills

• Strong coding experience with Laravel (5.5 and above) and Lumen
• Knowledge of PHP frameworks like CodeIgniter / YII / Zend / Joomla / Drupal etc will be a plus point.
• Strong skills in OOPs PHP, MySQL, CSS, HTML5, jQuery, JavaScript, AJAX, Web Services, JSON.
• Must have used frameworks such as JQuery /Angular/ React JS/Backbone.
• Strong knowledge of design patterns and OOPs concepts.
• Experience with databases like MySQL / MariaDB / Postgres.
• Experience in Source Code Versioning GitHub / GitLab / BitBucket and continuous integration tools like Jenkins.
• Working knowledge of XML / JSON and third-party APIs.
• Good to have skills: knowledge of non-relational databases like MongoDB; Exposure to Varnish, Redis, Elastic Search, Apache Solr.
• Payment processing integration experience in a PCI compliant environment is a plus
  Understanding of web and application security (OWASP)
• Experience in common third-party APIs (Google, Facebook, Twitter, Instagram, etc.)
• Good written and verbal communication with good analytical and multitasking skills
  
  

https://www.alivecor.com/">AliveCor, the pioneer of the smartphone EKG, with millions of EKGs from a large and growing user base, seeks a Senior Software Engineer (Backend). You will be an integral member of our engineering team.

• Software Engineer on the backend team working in the following environment: Go, Ruby on Rails, TDD/BDD with RSpec, PostgreSQL, Heroku, AWS. 
• Responsible for developing industry-leading applications transforming the healthcare industry and consumers use.
• Work with our mobile and front-end teams to build new functionality in our consumer and clinician-facing applications.
• Work with our Data Science and AI team to improve functionality of our cloud algorithms and services.
• Create and maintain tools used by internal teams for customer service, monitoring, and R&D.
• Maintain and continuously improve our backend infrastructure to remedy technical limitations before they become an issue.

• Senior Software Engineer ready to build highly visible apps
• Engineers who can raise the skill level of their teammates
• Experience working with Go and Rails
• Experience implementing Service Oriented Architecture or Microservices
• Good intuition for weighing trade-offs
• Product instincts, work with our product and design teams to understand customer pain points, come up with solutions, and then prototype, iterate, and launch frequently
• Eagerness and willingness to learn new technologies
• Experience with build process automation and CI/CD
• Ability to work independently on projects and communicate with cross functional teams to deliver products on time

AliveCor is on a mission to define modern healthcare through data, design and disruption. We’ve pioneered the creation of FDA-cleared machine-learning techniques, transformed wearable medtech to put proactive heart care at everyone’s fingertips. Kardia is the most clinically validated mobile EKG technology. AliveCor was named as one of the Top 10 Most Innovative Companies in Health for 2017 by Fast Company as part of the publication’s annual ranking of the world’s Most Innovative Companies. AliveCor was awarded the 2015 Tech Pioneer by the World Economic Forum and one of the 50 Smartest Companies in 2015 by the MIT Technology Review. AliveCor recently announced a collaboration with Mayo Clinic that will result in new machine learning capabilities to unlock previously hidden health indicators in EKG data, potentially improving heart health as well as overall health care for a variety of conditions. AliveCor is a privately held company headquartered in Mountain View, CA.

AliveCor is an equal opportunity employer and will not discriminate against any employee or applicant on the basis of age, colour, disability, gender, national origin, race, religion, sexual orientation, or any other classification protected by federal, state, or local law.

Watch the following video demonstrating our product.