Backend Engineer (AI-First | FinTech / Crypto)

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.

At BigThinkCode, our technology solves complex problems. We are looking for talented back-end (node.JS) engineer to join our at Chennai.

Please find below our job description, if interested apply / reply sharing your profile to connect and discuss.

Company: BigThinkCode Technologies

URL: https://www.bigthinkcode.com/

Experience required: 3-4 years

Work location: Chennai

Joining time: Immediate – 4 weeks

Work Mode: Work from office / Hybrid

Must have skills:

·      Hands on expertise in OOJS, node.js, distributed systems.

·      Event drive architecture (EDA) microservices project experience MUST

·      Any programming: Typescript or nodeJS or Golang

·      Hands on experience using docket containers and Kubernetes.

·      Aware about Asynchronous and Loose Coupling.

·      Familiar with API’s gateway and microservice design patterns.

A skilled Node.js Developer with 5+ years of experience in building scalable applications using event-driven architecture within distributed systems. The ideal candidate should be comfortable in high-performance backend services and have a strong understanding of asynchronous programming patterns.

Experience or exposure to knowledge embedding and vectorization techniques is a strong plus, especially in the context of modern data-driven or AI-powered systems.

Required Skills

·      5+ years of hands-on experience with Node.js

·      Strong understanding of event-driven architecture and non-blocking I/O

·      Experience working with distributed systems and microservices architecture

·      Proficiency in RESTful API design and implementation

·      Experience with databases such as MongoDB, PostgreSQL, or MySQL

·      Experience with containerization tools like Docker and orchestration tools like Kubernetes

Key Responsibilities

·      Design, develop, and maintain server-side applications using Node.js

·      Build and optimize scalable, event-driven systems in distributed environments

·      Implement asynchronous workflows, message queues, and pub/sub architectures

·      Collaborate with cross-functional teams to define and deliver backend solutions

Good to Have 

·      Experience with knowledge embedding and vectorization techniques

·      Familiarity with vector databases (e.g., Pinecone, Weaviate, FAISS)

·      Understanding of cloud platforms (AWS, Azure, or GCP)

Why Join Us:

·      Collaborative work environment.

·      Exposure to modern tools and scalable application architectures.

·      Medical cover for employee and eligible dependents.

·      Tax beneficial salary structure.

·      Comprehensive leave policy

·      Competency development training programs.

🚀Job Title : Senior Backend Engineer (Java / Golang) SDE 3

Experience : 5 to 12 Years

Positions : 4

Employment Type : C2H (Contract to Hire)

Contract Duration : 3 Months

Location : Remote during contract → Pune after conversion

Work Mode After Conversion : 5 Days WFO

Notice Period : Immediate / Serving Notice / Up to 15 Days preferred

Mandatory Skills : Golang (1+ year mandatory), 5+ years Backend Development, System Design, Distributed Systems, Microservices, REST / GraphQL APIs, Event-Driven Architecture, SQL & NoSQL Databases, AWS / GCP / Azure, Strong Problem-Solving & Communication Skills.

About the Role :

We are looking for an experienced Backend Engineer / SDE 3 with strong expertise in Java / Golang to design and build scalable, secure, and high-performance backend services and APIs.

The role involves hands-on coding, system design, microservices, distributed systems, and collaboration with engineering and infrastructure teams.

Must-Have Skills :

• 5+ years of backend development experience.
• Strong hands-on experience with Golang.
• Minimum 1+ year of Golang experience is mandatory.
• Strong understanding of System Design & Distributed Systems.
• Experience with REST / GraphQL APIs.
• Experience with Microservices and Event-Driven Architecture.
• Experience with Event Queues / Asynchronous Processing.
• Strong knowledge of Relational and NoSQL databases.
• Familiarity with AWS, GCP, or Azure.
• Strong communication and problem-solving skills.

Important Note for Java Candidates :

Java candidates can be considered only if they have at least 1+ year of hands-on Golang experience and are willing to work in Golang.

Candidates with less than 1 year of Golang experience will not be considered.

Good to Have :

• Experience in Fintech / Payments / Transaction-heavy systems
• Docker & Kubernetes
• Datadog / Prometheus / Grafana
• CI/CD experience
• Exposure to Java or Ruby

Key Responsibilities :

• Design, develop, and maintain scalable backend services using Golang.
• Build reliable, secure, and high-performance microservices and APIs.
• Implement event-driven and asynchronous processing systems.
• Work on system architecture, scalability, performance, and reliability.
• Participate in system design, code reviews, and technical discussions.
• Collaborate with mobile, web, and infrastructure teams.
• Develop unit, integration, and performance tests.
• Contribute to CI/CD, observability, documentation, and engineering best practices.

Interview Process :

Round 1 : Take-Home Coding Assessment – Submission within 48 hours

Round 2 : Code Pairing – Problem Extension

Round 3 : Culture Fitment

Strong Backend Software Engineer Profile with strong Core Java expertise

2

Mandatory (Experience 1): Must have 2+ years of hands-on backend software engineering experience.

3

Mandatory (Experience 2): Must be able to design and implement moderately complex features with minimal supervision, and contribute to system design and architecture discussions.

4

Mandatory (Experience 3): Must be comfortable owning business-critical production components — maintaining connectors, handling customer escalations, security fixes, bug fixes, and building new features end-to-end.

5

Mandatory (Tech skill 1): Must have strong, current Core Java depth with solid, clear coding fundamentals — Java is the primary skill for this role. Deep hands-on core engineering strength matters more than framework knowledge.

6

Mandatory (Tech skill 2): Must have strong core backend engineering fundamentals and experience with scalable systems (connectors handle millions of events/data points daily across customers).

7

Mandatory (Tech skill 3): Must have microservices experience.

8

Mandatory (AI Fluency 1): Must have demonstrated, hands-on use of AI coding assistants (Claude, GitHub Copilot, Cursor, etc.) as a core part of the daily workflow — scaffolding, writing tests, reviewing code, and debugging.

9

Mandatory (AI Fluency 2): Must be able to write precise, effective prompts for production-quality output, decompose tasks so AI assistance is effective, and critically evaluate AI-generated code for correctness, security, and standards before merging.

10

Mandatory (Company): Must come from a product company background (B2B SaaS or B2C both acceptable).

11

Mandatory (Note1): This is a 3-month contract role. Candidate must be comfortable with the contract engagement and able to join immediately (urgent — onboarding within ~a week)

12

Mandatory (Note 2): Must be based in or near Chennai, Bangalore, or Ahmedabad (Chennai: hybrid, Tue & Thu in office)

13

Preferred (Backend): Hands-on Python experience is a plus.

14

Preferred (Database): Hands-on database / JDBC integration experience in a production environment.

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.

Total Experience: 2+ years

Mode Of Hire: Permanent

Required Skills Set (Mandatory): Object Oriented Programming, data structures, algorithms, software design, and database systems.

Desired Skills (Good if you have): Springboot, ElasticSearch, MongoDB, MySQL, Redis, Crawling/ Web Scraping, Programming languages(Java, Python, C, C++)

Job Responsibilities

• Collaborate with Managers and other Engineers to help define, scope, and implement high-quality features that solve critical user needs.
• Break down requirements into architecture and deliver code, while keeping operational issues in mind.
• The ability to own end-to-end responsibility right from the requirement to release.
• Write clear documentation so that other engineers can jump in and get things done.
• Actively participate in design and code reviews.
• Help take Tracxn to the next level as a world-class engineering team

Job Requirements

• ​​Experience with building backend services. Strong algorithm and CS skills.
• Experience designing and implementing large‐scale distributed systems.
• Experience with multiple programming languages (Java, Python) and data stores (MongoDB, MySQL, Redis, etc)
• Proven ability to work in a fast-paced, agile, and in ownership, and results-oriented culture.
• Strong problem-solving and analytical skills.

Culture

• Work with performance-oriented teams driven by ownership and passion.
• Learn to design systems for high accuracy, efficiency, and scalability.
• No strict deadlines focus on delivering quality work.
• Meritocracy-driven, candid culture. No politics.
• Very high visibility regarding which startups and markets are exciting globally.

About Tracxn

Tracxn (Tracxn.com) is a Bangalore-based product company providing a research and deal sourcing platform for Venture Capital, Private Equity, Corp Dev, and professionals working around the startup ecosystem. We are a team of 800+ working professionals serving customers across the globe. Our clients include Funds like Andreessen Horowitz, Matrix Partners, GGV Capital, and Large Corporations such as Citi, Embraer & Ferrero.

Founders

• Neha Singh (ex-Sequoia, BCG | MBA - Stanford GSB)
• Abhishek Goyal (ex-Accel Partners, Amazon | BTech - IIT Kanpur)

About Technology Team

Tracxn's Technology team is 50+ members strong and growing. The technology team is subdivided into multiple smaller teams, each of which owns one or more services/components of the technology platform. Ours is a young team of motivated engineers with a minimal management structure where almost everyone is actively involved in technical development and design activities. We have a team-centric culture where the ownership and responsibility of a feature or module lie with a team as compared to an individual.

We work on an array of technologies, including but not limited to Spring, Elastic Stack, Kafka, Mongo, MySQL, Redis, ReactJS, Next.js, Node, AWS Lambda, Ansible, etc. 

We value ownership, continuous learning, consistency, and discipline as a team.

Java backend (Java + Kafka)

Bangalore

5+yrs

immediate to 15days

Java, Spring Boot, Kafka, microservice

Call or WhatsApp: 6 3 8 5 0 7 6 1 4 2

Strong Backend Software Engineer Profile with strong Core Java expertise

2

Mandatory (Experience 1): Must have 2+ years of hands-on backend software engineering experience.

3

Mandatory (Experience 2): Must be able to design and implement moderately complex features with minimal supervision, and contribute to system design and architecture discussions.

4

Mandatory (Experience 3): Must be comfortable owning business-critical production components — maintaining connectors, handling customer escalations, security fixes, bug fixes, and building new features end-to-end.

5

Mandatory (Tech skill 1): Must have strong, current Core Java depth with solid, clear coding fundamentals — Java is the primary skill for this role. Deep hands-on core engineering strength matters more than framework knowledge.

6

Mandatory (Tech skill 2): Must have strong core backend engineering fundamentals and experience with scalable systems (connectors handle millions of events/data points daily across customers).

7

Mandatory (Tech skill 3): Must have microservices experience.

8

Mandatory (AI Fluency): Must have demonstrated, hands-on use of AI coding assistants (Claude, GitHub Copilot, Cursor, etc.) as a core part of the daily workflow — scaffolding, writing tests, reviewing code, and debugging — with the ability to write precise, effective prompts for production-quality output, decompose tasks so AI assistance is effective, and critically evaluate AI-generated code for correctness, security, and standards before merging.

9

Mandatory (AI-Native): Must have actually built and deployed AI/LLM-powered features in production (e.g. RAG, LLM-based scoring, AI assistant) — demonstrable AI-native engineering, not merely using AI tools to write code.

10

Mandatory (Database): Hands-on database / JDBC integration experience in a production environment.

11

Mandatory (Company): Must come from a product company background (B2B SaaS or B2C both acceptable).

12

Mandatory (Note1): This is a 3-month contract role. Candidate must be comfortable with the contract engagement and able to join immediately (urgent — onboarding within ~a week)

13

Mandatory (Note 2): Must be based in or near Chennai, Bangalore, or Ahmedabad (Chennai: hybrid, Tue & Thu in office)

14

Preferred (Backend): Hands-on Python experience is a plus.

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. We're seeking an experienced Backend Software Engineer 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.

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

● Participate in code reviews and contribute to the improvement of the codebase

● Debug and resolve issues in the existing codebase

● Develop and execute unit tests to ensure high code quality

● Work with DevOps engineers to ensure seamless deployment of software changes

● Monitor application performance, identify bottlenecks, and optimize systems for better scalability and efficiency

● Stay up-to-date with industry trends and emerging technologies; advocate for best practices and new ideas within the team

● Collaborate with cross-functional teams to identify and prioritize project requirements

Requirements:

● At least 3+ 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

● 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 environmen

● Ready to be a tech-agnostic engineer and comfortable to shift on any tech stack (Java, Node, Python etc)

● Comfortable working with AI (Claude code, Cursor etc)

Job Overview

Architect and build scalable, high-performance backend systems while working on mission-critical platforms that process real-time market data and portfolio analytics. The role also involves leveraging Generative AI capabilities to enhance data intelligence, automation, and user-facing features, while ensuring regulatory compliance and secure financial transactions.

Key Responsibilities

• Design, develop, and maintain scalable backend services and APIs using NodeJS and Python
• Build event-driven architectures using RabbitMQ and Kafka for real-time data processing
• Develop and manage data pipelines integrating PostgreSQL and BigQuery for analytics and warehousing
• Integrate and deploy Generative AI models (LLMs, embeddings, AI APIs) into backend systems for automation, insights, and intelligent workflows
• Design AI-powered features such as recommendation systems, document processing, or conversational interfaces
• Ensure system reliability, security, and low-latency performance for mission-critical systems
• Lead technical design discussions, conduct code reviews, and mentor junior engineers
• Optimize database queries, implement caching strategies, and improve overall system performance
• Collaborate with cross-functional teams to deliver end-to-end product features
• Implement monitoring, logging, and observability solutions

Required Skills and Qualifications

• 2+ years of professional backend development experience
• Strong expertise in NodeJS and Python for production-grade applications
• Proven experience building RESTful APIs and microservices architectures
• Experience working with Generative AI frameworks/APIs (OpenAI, LangChain, vector databases, prompt engineering)
• Understanding of integrating LLMs into production systems (RAG, embeddings, fine-tuning basics)
• Strong proficiency in PostgreSQL, including query optimization and schema design
• Hands-on experience with RabbitMQ and Kafka
• Experience with BigQuery or similar data warehousing solutions
• Solid understanding of distributed systems, scalability patterns, and high-traffic applications
• Strong knowledge of authentication, authorization, and security best practices
• Experience with Git, CI/CD pipelines, and modern development workflows
• Excellent problem-solving and debugging skills
• Exposure to fintech or financial services, cloud platforms (GCP/AWS/Azure), Docker/Kubernetes, caching tools (Redis/Memcached), and regulatory requirements (KYC, compliance, data privacy) is a plus

Apply directly at: https://wohlig.keka.com/careers/jobdetails/136351