Senior Software Development Engineer (Payments) Full-time

Role Overview

We are looking for a Senior Full Stack Developer to build and scale our fintech platform. You will own the entire lifecycle of our financial products, from designing high-performance relational schemas in PostgreSQL to building interactive dashboards in React.

Key Responsibilities

• Full Stack Development: Build and maintain end-to-end features using the PERN stack

(PostgreSQL, Express.js, React, Node.js).

• Database Optimization: Design complex relational models and optimize SQL queries to

handle high-volume financial data and audit trails.

• Security & Compliance: Implement rigorous security measures (e.g., JWT, OAuth, data

encryption) and ensure the platform adheres to fintech standards like PCI-DSS.

• API Architecture: Develop robust RESTful APIs to integrate with third-party banking APIs,

payment processors (Stripe/Plaid), and KYC providers.

Technical Requirements

• Front-end: Advanced proficiency in React.js (Hooks, Context API, Redux or TanStack Query)

and modern CSS (Tailwind/Styled Components).

• Back-end: Expert-level Node.js and Express.js experience, with a focus on asynchronous

programming and secure API design.

• Database: Deep knowledge of PostgreSQL (complex joins, indexing, triggers, and

migrations).

Additional skills

• Understanding of Event-Driven Architecture (using AWS SQS/SNS or Kafka).

• Familiarity with SOC2 or ISO 27001 compliance frameworks.

• Cloud (AWS): Proven experience with:

• RDS/Aurora for managed databases.
• IAM for secure access management.
• AWS Lambda & API Gateway for serverless architecture.
• CloudWatch for monitoring and alerting.

• Tools: Git, Docker, and experience with CI/CD workflows.

About US

RJ Fintech Solutions Pvt. Ltd. is a high-growth fintech startup on a mission to automate business financial operations. In a world where financial systems are often slow and opaque, we are building the "missing link"—a secure, transparent, and lightning-fast platform that puts banking and compliance first for various corporates.

We are not just another financial app; we are an engineering-first company. We believe that elegant code and robust architecture are the foundations of trust. By leveraging the PERN stack and AWS cloud-native infrastructure, we are replacing legacy complexity with modern, scalable solutions.

Why Work With Us?

1. Build the Foundation, Not Just Features

You won't be a small cog in a massive machine. As an early member of our engineering team, you will help define our technical architecture, choose our libraries, and set the coding standards for everyone who follows. Your fingerprints will be on the core DNA of our product.

2. Solve Problems That Matter

Fintech is one of the few industries where code has a direct, measurable impact on people's lives.

Whether we are [e.g., simplifying cross-border payments, democratizing investment, or building the next generation of credit], you will be solving high-stakes challenges around security, trust, and financial inclusion.

About the Role

Unico Connect is an AI-first technology partner that builds custom mobile, web, and AI products for clients across multiple geographies. We are hiring a Backend Engineer for a dedicated client engagement building an AI-powered application builder platform.

The backend is the operational core of the product: it manages user projects and sessions, coordinates long-running AI agent workloads, maintains project state, and serves as the integration layer between the frontend, the AI system, and the underlying infrastructure.

The mandatory requirement is hands-on production experience shipping Node.js services, with end-to-end ownership of API design, data modelling, and at least one production system involving background job processing or event-driven patterns.

Responsibilities

API and service development: Design and build REST APIs in Node.js with TypeScript. Cover authentication, session management, input validation, structured error handling, streaming responses (SSE, WebSockets), and rate limiting. Maintain clean API contracts that the frontend and AI system can rely on.

Database design and management: Own PostgreSQL schema design for product domains including user accounts, projects, file trees, session state, and generated artefacts. Write efficient queries, manage migrations, and optimise for read patterns that serve a real-time editor experience.

Caching strategy: Implement and maintain caching with Redis for session data, project state, and frequently read configuration. Design cache invalidation logic that keeps the editor experience consistent without stale reads.

Queue and background job management: Implement and operate background job infrastructure using BullMQ or equivalent. AI agent runs are long-running and stateful; handle retries, failure states, priority queues, and concurrency limits.

AI system integration: Build the integration layer between the backend and the AI agent system. Manage job dispatch, result handling, streaming output to the frontend, and error propagation.

Multi-tenancy and access control: Implement tenant data isolation, RBAC, and resource ownership enforcement across all API surfaces.

Observability and reliability: Instrument services with structured logging, metrics, and tracing. Write defensive code with sensible timeouts, fallback behaviour, and circuit breaking on external dependencies.

Testing and code quality: Write unit and integration tests for the services you ship. Review the work of peers and contribute to shared engineering conventions.

Requirements

• Hands-on production Node.js experience (mandatory) — must have personally shipped at least one feature area end to end in a production Node.js service, owning API design, data modelling, and testing.

• 3 to 5 years of professional backend engineering experience. Candidates with slightly less time but strong demonstrated ownership are welcome to apply.

• Strong Node.js and TypeScript. Production experience with Express, NestJS, or Fastify. Solid with async patterns, streaming, error handling, and building services that run reliably under sustained load.

• PostgreSQL depth. Schema design, query writing, indexing, and migrations on at least one production system.

• Redis and caching. Production experience using Redis for caching and session management. Understands cache invalidation trade-offs.

• Queue and background job systems. Hands-on with BullMQ, RabbitMQ, SQS, or equivalent. Experience managing retries, dead-letter queues, job priority, and concurrency control.

• AWS working knowledge. Comfortable with EC2, S3, RDS, SQS, and IAM. Familiar with Docker and basic deployment and environment management.

• Strong written and spoken English. Able to communicate clearly with engineers across disciplines and write precise technical documentation.

Nice to Have

Experience integrating with AI or LLM services (streaming responses, structured outputs, retry patterns); WebSocket or SSE implementation for real-time features; multi-tenant SaaS product experience; GraphQL; OpenTelemetry instrumentation; prior work on developer tools or editor-style products.

Why This Role Matters

Our backend is what keeps checkout, RTO, and payments fast and reliable at ~$2B GMV across 15,000+ merchants. As an SDE 2 you own services end to end, make the architecture calls that keep them performant, and set the technical bar for the engineers around you. The trade-offs you pick show up directly in merchant conversions and platform reliability - this is a builder's seat with real ownership.

What You'll Own

• Design and build backend services primarily in Node.js/NestJS, with Go for select services, backed by Postgres, Mongo, and Redis.
• Own event-driven flows on Kafka - throughput, ordering, and failure handling.
• Make and document the architecture and trade-off decisions for systems you lead.
• Ship features end to end, dropping into the frontend (React/Svelte) when it's the fastest path.
• Strengthen CI/CD, observability, and deployments on AWS.
• Review code, mentor SDE 1s and AEs, and raise the quality bar on the team.
• Take ambiguous problems and drive them to delivery with minimal hand-holding.

Who You Are

• Strong backend engineer in JavaScript/TypeScript on Node.js/NestJS (our primary stack); working knowledge of Go, or ready to pick it up.
• Solid at data modelling across Postgres and Mongo, and knows when Redis earns its place.
• Has built and scaled event-driven systems (Kafka or equivalent).
• At home on the backend but happy to work across the stack in React/Svelte.
• Thinks in systems - scalability, reliability, maintainability - not just features.
• Has mentored engineers and owns code quality and delivery, not just their own tickets.
• Communicates clearly and does well with ambiguity in a fast-moving team.

Strong Software Engineer fullstack profile using NodeJS, Python, and React

2

Mandatory (Experience) - Must have 6+ YOE in Software Development using Python and NodeJS (For backend) & React (For frontend)

3

Mandatory (Core Skills 1): Must have strong experience in working on Typescript

4

Mandatory (Core Skills 2): Must have experience in message based systems like Kafka, RabbitMq, Redis

5

Mandatory (Core Skills 3): Databases - PostgreSQL & NoSQL databases like MongoDB

6

Mandatory (Company) - Product Companies Only

7

Mandatory (Education) - B.Tech or Dual degree (Btech and Mtech or Integrated Msc/MS) from Tier 1 Engineering Institutes (IITs, not NITs). Candidates from other institutions will not be considered unless they come from top-tier product companies

8

Mandatory (Note) : This role is a hybrid role (2 days WFO)

9

Preferred (Experience): Experience in Fin-Tech, Payment, POS and Retail products is highly preferred

10

Preferred (Mentoring): Experience in mentoring, coaching the team.

Strong Software Engineer fullstack profile using NodeJS, Python, and React

2

Mandatory (Experience) - Must have 6+ YOE in Software Development using Python and NodeJS (For backend) & React (For frontend)

3

Mandatory (Core Skills 1): Must have strong experience in working on Typescript

4

Mandatory (Core Skills 2): Must have experience in message based systems like Kafka, RabbitMq, Redis

5

Mandatory (Core Skills 3): Databases - PostgreSQL & NoSQL databases like MongoDB

6

Mandatory (Company) - Product Companies Only

7

Mandatory (Education) - B.Tech or Dual degree (Btech and Mtech or Integrated Msc/MS) from Tier 1 Engineering Institutes (IITs, not NITs). Candidates from other institutions will not be considered unless they come from top-tier product companies

8

Mandatory (Note) : This role is a hybrid role (2 days WFO)

9

Preferred (Experience): Experience in Fin-Tech, Payment, POS and Retail products is highly preferred

10

Preferred (Mentoring): Experience in mentoring, coaching the team.

Job Title: Software Engineer / Senior Software Engineer – Java Backend

Experience: 5–10 Years

Location: Pune (Baner) – Work from Office (5 Days a Week)

About the Role :

We are looking for passionate Java Backend Engineers to build highly scalable, high-performance enterprise applications used by millions of users globally. The ideal candidate should have strong experience in Java, Microservices, Payment Gateway integrations, and Checkout platform development, with a product engineering mindset.

Candidates from FinTech, E-commerce, Payments, or Product-based companies will be preferred.

Key Responsibilities :

Design, develop, and maintain scalable backend applications using Java and Microservices.

Build secure, high-performance REST APIs and distributed services.

Develop and enhance Checkout platforms and Payment Gateway integrations for seamless payment processing.

Collaborate with Product, Architecture, QA, and DevOps teams throughout the SDLC.

Participate in system design, architecture discussions, and technical decision-making.

Ensure high code quality through unit testing, code reviews, and engineering best practices.

Build and support CI/CD pipelines and containerized deployments.

Troubleshoot production issues, optimize performance, and improve application reliability.

Mentor junior engineers and contribute to engineering excellence.

Required Skills :

5–10 years of backend development experience.

Strong expertise in Java, Spring Boot, Spring MVC, Hibernate/JPA.

Hands-on experience with Microservices Architecture.

Experience building RESTful APIs.

Strong knowledge of SQL/NoSQL databases.

Experience with Payment Gateway Integration (Stripe, Adyen, Razorpay, Worldpay, PayU, Checkout.com, etc.).

Hands-on experience developing Checkout and Payment Processing workflows.

Understanding of Payment Lifecycle, including Authorization, Capture, Refunds, Settlement, Webhooks, and Transaction Management.

Experience with Docker, Kubernetes, and containerized applications.

Good understanding of CI/CD pipelines using Jenkins or similar tools.

Familiarity with Git, Agile methodologies, and engineering best practices.

Strong problem-solving and debugging skills.

Preferred Skills :

Experience working in FinTech, Payments, E-commerce, or Product-based organizations.

Exposure to Cloud Platforms (GCP/AWS/Azure).

Experience with Kafka or event-driven architecture.

Knowledge of OAuth2, JWT, Keycloak, or similar authentication mechanisms.

Experience with Monitoring & Observability tools (Grafana, Prometheus, ELK, Splunk).

Performance tuning and scalability optimization experience.

Preferred Background :

Candidates from FinTech, Digital Payments, Banking Products, E-commerce, or Product Engineering companies.

Experience working on high-volume transaction systems handling secure payment processing and checkout experiences.

We’re building financial data systems that power real business decisions — and we need someone who knows how to make Django, PostgreSQL, Celery, and APIs play nicely at scale.

You know what clean, reliable backend systems look like — because you’ve built them. You’ve handled authentication quirks, rate limits, and webhooks; you build code that’s maintainable, performant, and correct.

If you’re curious about financial data, transactions, and KPIs, and enjoy turning numbers into insight, this role is for you. (Experience with banking or accounting APIs is a big plus.)

What You’ll Do

• Build and maintain Django-based systems using Celery for async and scheduled tasks
• Integrate and manage data from multiple APIs (banking, accounting, analytics, etc.)
• Design and optimize internal APIs
• Improve reliability, scalability, and performance
• Collaborate closely with product and frontend engineers

Your Profile

You’re an experienced backend engineer who is strong in all core areas of modern Python development:

• Python, Django, Django REST Framework
• Celery and asynchronous / distributed task handling
• PostgreSQL and robust data modeling
• Docker and containerized deployment workflows
• Unit testing (pytest or equivalent) and maintainable test structures
• Git, CI/CD, and reliable deployment automation
• API integrations (REST, OAuth, webhooks)
• Caching strategies & background job handling (preferred Redis experience)
• Solid understanding of security, permissions, and performance optimization

You’ve already built or scaled production-grade systems and can take ownership from architecture to deployment.

Experience with fintech or data integration systems is an advantage.

How We Work

We’re a small, remote-first team that values ownership over micromanagement.

You’ll have freedom in how you work — what matters is your impact.

Our daily language is English.

About finban

We’re building a platform that helps businesses understand and manage their financial performance in real time by connecting and analyzing data from banking, accounting, and analytics systems.

If you’ve built or scaled production Django systems before and love clean architecture — we’d love to see your work.

About NonStop io Technologies

NonStop io Technologies is a value-driven company with a strong focus on process-oriented software engineering. We specialize in Product Development and have a decade's worth of experience in building web and mobile applications across various domains. NonStop io Technologies follows core principles that guide its operations and believes in staying invested in a product's vision for the long term. We are a small but proud group of individuals who believe in the 'givers gain' philosophy and strive to provide value in order to seek value. We are committed to and specialize in building cutting-edge technology products and serving as trusted technology partners for startups and enterprises. We pride ourselves on fostering innovation, learning, and community engagement. Join us to work on impactful projects in a collaborative and vibrant environment.

Brief Description

We're seeking an experienced Senior Backend Engineer/Tech Lead to join our team. As a backend engineer, you will be responsible for designing, developing, and deploying scalable backends for the products we build at NonStop. This includes APIs, databases, and server-side logic. Also, guiding the mentoring the junior team members

Responsibilities

• Design, develop, and deploy backend systems, including APIs, databases, and server-side logic
• Write clean, efficient, and well-documented code that adheres to industry standards and best practices
• Code Quality: Ensure code quality through code reviews, adherence to best practices, and continuous improvement
• Mentorship: Guide and mentor team members, fostering growth and innovation
• Collaboration: Work closely with stakeholders to align technical goals with business objectives
• Problem-Solving: Analyze and resolve technical challenges promptly
• Innovation: Stay updated with the latest technology trends and integrate them into solutions

Requirements

• At least 5+ years of experience building scalable and reliable backend systems
• Strong expertise in NodeJS/NestJS, Express, PostgreSQL
• Experience with microservices architecture and distributed systems
• Proficiency in database design (SQL and NoSQL)
• Knowledge of cloud platforms (AWS, Azure, or GCP) and CI/CD pipelines
• Deep understanding of design patterns, data structures, and algorithms
• Hands-on experience with containerization technologies like Docker and orchestration tools like Kubernetes
• Familiarity with Frontend Development Technologies (React, JavaScript, HTML, CSS)
• Exceptional communication and leadership skills
• Strong understanding of object-oriented programming principles and design patterns
• Familiarity with automated testing frameworks and methodologies
• Excellent problem-solving skills and attention to detail
• Strong communication skills and ability to effectively lead and maintain a collaborative team environment

Why Join Us?

• Opportunity to work on a cutting-edge healthcare product
• A collaborative and learning-driven environment
• Exposure to AI and software engineering innovations
• Excellent work ethic and culture

If you're passionate about technology and want to work on impactful projects, we'd love to hear from you!

Role & Responsibilities

We are currently seeking a Senior Engineer to join our Financial Services team, contributing to the design and development of scalable system.

The Ideal Candidate Will Be Able To-

• Take ownership of delivering performant, scalable and high quality cloud based software, both frontend and backend side.
• Mentor team members to develop in line with product requirements.
• Collaborate with Senior Architect for design and technology choices for product development roadmap.
• Do code reviews.

Ideal Candidate

• Strong Software Engineer fullstack profile using NodeJS, Python, and React
• Mandatory (Experience) - Must have 6+ YOE in Software Development using Python and NodeJS (For backend) & React (For frontend)
• Mandatory (Core Skills 1): Must have strong experience in working on Typescript
• Mandatory (Core Skills 2): Must have experience in message based systems like Kafka, RabbitMq, Redis
• Mandatory (Core Skills 3): Databases - PostgreSQL & NoSQL databases like MongoDB
• Mandatory (Company) - Product Companies Only
• Mandatory (Education) - B.Tech or Dual degree (Btech and Mtech or Integrated Msc/MS) from Tier 1 Engineering Institutes. Candidates from other institutions will not be considered unless they come from top-tier product companies
• Mandatory (Note) : This role is a hybrid role (2 days WFO)
• Preferred (Experience): Experience in Fin-Tech, Payment, POS and Retail products is highly preferred
• Preferred (Mentoring): Experience in mentoring, coaching the team.

We are building HypeMuse, an event-based photo and GIF discovery platform for sports games, concerts, and live events.

Our current backend is built with Laravel/PHP, and we are planning to rebuild the backend using Node.js. We are looking for a strong backend engineer who can help migrate the existing Laravel system into a scalable Node.js architecture while keeping the current product logic stable.

Responsibilities:

- Analyze the existing Laravel backend structure, database schema, APIs, and admin workflows.

- Rebuild core backend services using Node.js, preferably TypeScript with NestJS or Express.

- Design clean REST APIs for the mobile app, admin panel, media upload, user accounts, events, venues, and recommendation feed.

- Integrate with existing services including MySQL/PostgreSQL, Redis, object storage, and the recommendation service.

- Support event-based recommendation logic for photos and GIFs, including event ID, venue location, match phase, audience type, media quality, freshness, and popularity.

- Build background jobs for media processing, metadata sync, recommendation data sync, and interaction tracking.

- Set up Docker-based deployment and production-ready environment configuration.

- Improve backend performance, security, logging, monitoring, and maintainability.

- Work closely with the founder/product owner to turn the current Laravel backend into a scalable Node.js backend.

Requirements:

- Strong experience with Node.js backend development.

- Good knowledge of TypeScript, NestJS or Express.js.

- Experience working with Laravel/PHP projects and backend migration is highly preferred.

- Strong understanding of REST API design, authentication, database modeling, and queue-based systems.

- Experience with MySQL or PostgreSQL, Redis, Docker, and Linux server deployment.

- Ability to read an existing codebase and migrate features without breaking current product behavior.

- Experience with media platforms, recommendation systems, feeds, image/video processing, or event-based products is a plus.

Nice to have:

- Experience with Qdrant, Faiss, vector search, recommendation systems, or AI-powered media tagging.

- Experience with cloud storage, CDN, image optimization, and large-scale media upload.

- Experience with sports, concert, creator, or community platforms.

This role is suitable for someone who can work independently, communicate clearly, and help us move from a Laravel MVP backend to a more scalable Node.js backend architecture.