SDE-III Backend (Java)

Required Core Tech Stack:

We're looking for engineers with hands-on experience across most of the following technologies:

• Python Backend Development (3+ years)
• FastAPI (2+ years of production experience required)
• PostgreSQL
• MongoDB
• Redis
• Docker
• Celery or equivalent async task queues
• REST APIs & Microservices
• AWS/GCP
• GitLab CI/CD

The selected Sr. Backend engineer will ship the backbone that powers 4 million + learners in 64 countries—owning APIs that crunch 1 billion learning events & the AI that supports it with <200 ms latency.

What You'll Do:

At LearnTube, we’re pushing the boundaries to revolutionize how the world learns. As a Senior Backend Engineer, your roles and responsibilities will include:

• Shipping Micro-services – Build FastAPI services that handle ≈ 800 req/s today and will triple within a year (sub-200 ms p95).
• Power Real-Time Learning – Drive the quiz-scoring & AI-tutor engines that crunch millions of events daily.
• Design for Scale & Safety – Model data (Postgres, Mongo, Redis, SQS) and craft modular, secure back-end components from scratch.
• Deploy Globally – Roll out Dockerised services behind NGINX on AWS (EC2, S3, SQS) and GCP (GKE) via Kubernetes.
• Automate Releases – GitLab CI/CD + blue-green / canary = multiple safe prod deploys each week.
• Own Reliability – Instrument with Prometheus / Grafana, chase 99.9 % uptime, trim infra spend.
• Expose Gen-AI at Scale – Publish LLM inference & vector-search endpoints in partnership with the AI team.
• Ship Fast, Learn Fast – Work with founders, PMs, and designers in weekly ship rooms; take a feature from Figma to prod in < 2 weeks.

What makes you a great fit?

Must-Haves (Applicants without these skills are unlikely to move forward):

• 3+ yrs Python back-end experience (FastAPI)
• Strong with Docker & container orchestration
• Hands-on with GitLab CI/CD, AWS (EC2, S3, SQS) or GCP (GKE / Compute) in production
• SQL/NoSQL (Postgres, MongoDB) + You’ve built systems from scratch & have solid system-design fundamentals

Nice-to-Haves

• k8s at scale, Terraform,
• Experience with AI/ML inference services (LLMs, vector DBs)
• Observability: Prometheus, Grafana, OpenTelemetry

Why LearnTube?

• Build AI products at global scale – Your work will power learning experiences for 4M+ learners across 64 countries.
• Work directly with experienced founders – Collaborate closely with founders who are deeply involved in product and engineering decisions, giving you ownership and a direct impact on the product roadmap.
• Learn fast – Join a high-performing team where you'll own features end-to-end and solve challenging backend and distributed systems problems.
• Recognized AI startup – LearnTube is a Google Top 20 AI Startup and part of Google's AI First Startup Accelerator, with access to cutting-edge AI technology and mentorship.

Why Work With Us? 

At LearnTube, we believe in creating a work environment that’s as transformative as the products we build. Here’s why this role is an incredible opportunity:

• Cutting-Edge Technology: You’ll work on state-of-the-art generative AI applications, leveraging the latest advancements in LLMs, multimodal AI, and real-time systems.
• Autonomy and Ownership: Experience unparalleled flexibility and independence in a role where you’ll own high-impact projects from ideation to deployment.
• Rapid Growth: Accelerate your career by working on impactful projects that pack three years of learning and growth into one.
• Founder and Advisor Access: Collaborate directly with founders and industry experts, including the CTO of Inflection AI, to build transformative solutions.
• Team Culture: Join a close-knit team of high-performing engineers and innovators, where every voice matters, and Monday morning meetings are something to look forward to.
• Mission-Driven Impact: Be part of a company that’s redefining education for millions of learners and making AI accessible to everyone.

About PoshVine: 

PoshVine aspires to become the world's leading transaction-driven loyalty and engagement platform by providing a mutually beneficial ecosystem for people, banks and retailers. Our products around programmatic offers, rewards, and loyalty help retailers increase contextual engagement and financial institutions increase share of spends, while end-users maximize their rewards and savings. PoshVine works with all the global payment networks and many marquee financial institutions, including 7 of the top 10 banks in India. 

Backend Development at PoshVine:

We are building payment-linked real-time engagement tools embedded within banking and payment journeys. Our core engineering team strives to build solid backend foundations, infrastructure and a solid network of microservices. Apart from regular work, you can expect:

• Freedom to evaluate and introduce new tools, libraries and coding standards.
• Work on developer productivity and platform tooling.
• Evangelise tech and share knowledge in internal and external forums.
• Contribute to Product and Design ideas and implement them like it’s your own product. 

Roles & Responsibilities: 

1. Be involved in product and design decisions, and drive implementations. 
2. Help us scale the payment-linked loyalty infrastructure to every payment product used in India. Develop platform features for/with reusable code.
3. Work with IT/tech SPOCs from Banks and Fintechs to achieve seamless API integrations, resolve concerns, and move forward with program delivery and implementation. 
4. Tag team with internal and external stakeholders to problem solve and work with banks to test out UAT/Production and create a rollout plan for the same. 
5. Perform in-depth research and identify sources off production issues surrounding the application. 
6. Make architectural decisions (microservices, choice of development frameworks and tools, database optimisations, load handling)
7. Proficient in Full stack development skills spanning the entire spectrum from:

1. Database: MySQL, PostgreSQL
2. Backend: Ruby on Rails
3. Front End: Web Development frameworks  (Angular / React / Vue JS)
4. Deployment: Capistrano, Chef, AWS, EC2, Git

You’ll be a good fit if you possess: 

1. A strong product design sense.
2. Good experience in working with Ruby on Rails, Postgres, Python.
3. Proven ability to understand end user requirements, formulate use cases and come up with effective solutions.
4. Good understanding of REST APIs and the web in general.
5. Ability to build a feature from scratch & drive it to completion.
6. A willingness to learn new technology, whatever lets you deliver the best product.
7. Possess excellent data management skills: 
1. How to structure databases that can scale
2. How to optimise database queries
3. Complying with the latest regulations around data for each geography
4. Managing the infrastructure that the data resides on to ensure 99.9% uptime across geographies
8. You are comfortable working on CI/CD toolchain, Kubernetes, etc.
9. 3+ years of experience. 

• Strong knowledge of JavaScript.
• Knowledge of and its frameworks.
• Knowledge of NodeJS deployment over servers like AWS, the digital ocean.
• Good understanding of relational databases. Having experience with MongoDB will be an advantage.
• Proficiency in handling server-side development, deployment, and debugging.
• Having worked in socket programming is an added advantage.
• Good understanding of code versioning tools, such as Git.

• The developer should be well conversant with principles of clean codeand refactoring practices.
• The developer should have experience writing unit and integration tests.
• The developer should be conversant with agile development practices.
• Prior experience in Python is a good to have but the developer should be willing to do development in Python.
• The developer is expected to collaborate with developers from other teams as well as business stakeholders in India and in US to design and develop business requirements.

We are looking for motivated individuals who are keen to work on Cloud or Big Data services or have worked on Cloud and Big Data. If you want to work in a start-up culture and are ready for the challenge, then join us on our exciting journey.

Responsibilities:

• Design, code and debug cloud-native applications.
• Evaluate and identify new technologies for implementation
• Determine operational feasibility by evaluating analysis, problem definition, requirements, solution development and proposed solutions
• Write well designed, testable, efficient code
• Develop software verification plans and quality assurance procedures
• Serve as a subject matter expert

• 5+ years of relevant experience in software development

• Deep understanding of public cloud infrastructure (AWS, Azure or Google)

• Experience with large scale distributed systems

• Ability to troubleshoot distributed systems

• Prior experience with data encryption, TLS/SSL is a strong plus

• Experience with Docker and Kubernetes is a plus

• Deep experience with Java

• Excellent communication (writing, conversation, presentation) skills, consensus building, Quick learner
  Good to have experience in Production support - Tier 4
  
  Experience with these technologies are a plus: AWS, Microsoft Azure, Google Cloud, Cloudera, Snowflake, Mongo DB, Oracle, Databricks, Datastax, Confluent