Backend Developer

Are you looking to break out of the silo of pure-tech engineering and build systems that directly move millions in global revenue? If you want to own an entire, high-impact platform end-to-end and see the immediate business value of your code every single day, this is your playground. At Ultrahuman, you will act as a critical bridge between deep engineering and global market execution, turning data intelligence into autonomous, revenue-driving action across 100+ countries. 

About the Company: 

Ultrahuman is one of the world's fastest-growing wearable companies. The Ultrahuman Ring AIR — the world's lightest sleep-tracking smart ring — sells in 100+ countries. We operate like a product company in every function, and marketplaces is no exception: our Amazon business across the UK, Germany, Canada, Australia, India, the UAE and beyond runs on uh-amazon, an in-house platform we built ourselves. 

Role: Marketplace Platform Engineer 

Location: Begur, Bengaluru 

Schedule: Hybrid. 

Marketplace Platform Engineer 

Turn a read-only intelligence platform into the hands that run a global Amazon business. 

Why this role exists 

uh-amazon already does the seeing: a fleet of agents producing daily intelligence across every marketplace, an automated fulfillment middleware that intercepts and routes every order, and a self-hosted agent platform the team uses without writing code. But it writes almost nothing back to Amazon — every ads change, price correction, and listing push is still done by hand. That write side is unbuilt, and it is worth more than the entire team's cost: the daily briefs already flag large sums of recoverable ad spend that no one has the hands to recover. You will be the platform's owner and the team's force multiplier. 

What you'll own 

• The uh-amazon codebase end-to-end — the FastAPI middleware, the agent fleet, the self-hosted agent platform, and the deploy pipeline 
• The write side, behind staged approval gates — the order-management bridge first, then ads execution, repricing, and listing-push agents, each earning the right to act 
• Platform trust — kill the false-positive classes and fix the chronically failing agents, so the team acts on the briefs instead of second-guessing them 
• Operator self-serve — the team adds and tunes agents through the platform without touching code 

Your first 90 days 

• Ship the order-management bridge that removes the last manual step in fulfillment 
• Ship the first ads-execution agent behind a human approval gate, working the platform's existing recommendation lists 
• Eliminate the top false-positive classes in the daily briefs 

What we're looking for 

• Strong Python (FastAPI or similar) and real API-integration depth — OAuth, rate limits, retries, idempotency; you have built against messy third-party APIs in production 
• LLM-agent experience — you have built tool-using agents or LLM pipelines, designed prompts and tool schemas, and debugged why a model did something 
• Ship-fast evidence — small PRs, production ownership, comfort being the only engineer on a system 
• Comfort owning production writes against a live revenue channel, with gates and audit trails you design 

Strongly preferred 

• Amazon SP-API or Ads API experience specifically — this collapses your ramp to near zero 
• E-commerce domain (order management, marketplaces, repricing, feeds); container/orchestration experience 
• A public GitHub with real contributions 

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)

1. Proficiency in Python 3.x based web and backend development

2. Solid understanding of Python concepts

3. Experience with some form of Machine Learning (ML)

4. Experience in using libraries such as Numpy and Pandas

5. Some form of experience with NLP and Deep Learning using any of Pytorch, Tensorflow, Keras, Scikit-learn or similar

6. Hands on experience with RDBMS such as Postgres or MySQL

7. Experience building REST APIs using DRF or Flask

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

Position Overview:

We are seeking a skilled Java Developer to join our dynamic team. The ideal candidate will have a strong foundation in Core Java and extensive experience in developing and deploying applications using Spring Boot, Apache Tomcat, and other related technologies. The candidate should possess expertise in building Restful Web Services, Microservices architecture, and be proficient in implementing multi-threading concepts.

Additionally, experience with Maven, Git, Jenkins, and Agile Scrum methodologies is essential for this role. The candidate should also have a solid understanding of software development lifecycle (SDLC) processes. Familiarity with various databases such as MySQL, PostgreSQL, Oracle, or MongoDB, along with third-party API integration and payment gateway integration, is required.

Key Responsibilities:

• Develop, test, deploy, and maintain Java-based applications.

• Design and implement Restful Web Services and Microservices using Spring Boot.

• Utilize multi-threading concepts to enhance application performance.

• Integrate third-party APIs and payment gateways into applications.

• Collaborate with cross-functional teams to gather requirements and deliver high-quality solutions.

• Participate in Agile Scrum ceremonies and contribute to sprint planning, backlog grooming, and retrospectives.

• Ensure adherence to best practices and coding standards.

• Conduct code reviews and provide constructive feedback to peers.

• Troubleshoot and debug complex issues in production environments.

• Document design decisions, processes, and procedures.

Required Qualifications:

• Bachelor’s degree in computer science, Engineering, or related field.

• Minimum 3 years of experience as a Java Developer with expertise in Core Java.

• Strong knowledge of Spring Boot, Apache Tomcat, and multi-threading concepts.

• Hands-on experience in building Restful Web Services and Microservices architecture.

• Proficiency in using Maven, Git, and Jenkins for build and deployment processes.

• Familiarity with Agile Scrum methodologies and SDLC processes.

• Experience working with databases such as MySQL, PostgreSQL, Oracle, or MongoDB.

• Demonstrated ability to integrate third-party APIs and payment gateways.

• Excellent problem-solving and analytical skills.

• Effective communication and collaboration skills.

• Familiarity with NoSQL databases like MongoDB.

• Knowledge of Azure DevOps for CI/CD pipelines

• 1-5 years of experience in Java Development.
• Very good with DSA - Java programming.
• Hands-on experience in working with REST APIs & Web Services.
• Good Database design skills - SQL
• Write well-designed, testable, efficient code.
• Contribute to all phases of the development lifecycle.

Work Location : Bangalore

Work mode : Work from office.

Primary Skills:

.Net/.Net Core, C#, OOPS and SQL Server as a key technology, which covers frontend and backend work. Knowledge of DevOps (building and deployment) and the Cloud is nice to have.

Roles & Responsibilities

Participate in requirements analysis.

Collaborate with internal teams to produce software design and architecture.

Write clean, scalable code using .NET programming languages.

Test and deploy applications and systems.

Revise, update, refactor and debug code.

Improve existing software.

Eligibility

3+ years of experience in building web applications. Passion for building and delivering great software with a strong sense of ownership

Advanced proficiency in C#, very clear OOPS concepts, In-depth knowledge of the .NET framework, ASP.NET, MVC, Web API, REST APIs, OAuth 2.0/ Authentication/ Authorization

Strong expertise in SQL programming, with experience of writing & optimizing queries that access/process millions of records

Good to have any scripting(powershell) knowledge, JS based UI Frameworks

Outstanding analytical, problem-solving, and communication skills

Experienced in complex logic designing and implementation

Should have worked in Agile development environment and best practices

Good to have experience in secure development practices

Java Backend Engineer - Fintech Rocketship Pilot

Distributed systems, scalability, reliability, robustness, security, quality, building responsive real time systems - do these terms get your adrenaline high? Come be a part of a high growth, fast paced engineering team building for India’s new generation.

We have an open culture, you take responsibility and ownership of what you do. No bureaucracy. No bullsh*t.

If you are up for big engineering challenges, personal and professional growth, then let’s join forces!

You’ll fit right in if you have - 2-3 years of experience building, running and maintaining production services Strong with Java and JVM based services along with PostgreSQL Comfortable working with multiple cloud providers: mainly GCP and AWS Comfortable with CI and CD tools and best practices Done TDD and values TDD

Good to have –

Key Skills:

1. One or more of Python/PHP/Ruby/NodeJS/Java

2. Sound object-oriented skills, including strong design patterns knowledge

2. REST APIs

3. MVC architecture

4. MySQL/PostgreSQL

5. Exp with at least 1 NoSQL databases MongoDB/Memcache/Redis/

6. Exp with search technologies Elasticsearch/Solr

7. Exp building messaging based asynchrounous systems RabbitMQ/Kafka/SQS/Celery will be added advantage

8. Exp with Django/Flask frameworks will be added advantage

9. Knowledge of software best practices like Test-Driven Development (TDD) and Continuous Integration (CI) will be added adnavtage

Requirements:

1. Developing software solutions in conjunction with Relational theory, Rest APIs and NoSQL database technologies

2. Knowledge of cloud based technologies in AWS or Azure will be added advantage

3. Understanding of RDBMS technologies like MySQL, PostgreSQL.

4. Hands-on with Version control systems (GIT, SVN) and Unix/Ubuntu.

5. Experience in requirement analysis, HLD, LLD, unit & integration testing.

6. Good hands on experience in debugging application issues

TL;DR

1) Top performer in the company

2) Has worked with product based startup company

3) Ambitious and hardworking