Senior Backend Engineer (Java, Reactive Systems, Node.js)

Profile: Senior Backend Engineer (Java, Reactive Systems, Node.js) – Enterprise FinTech

About the Role

Senior Backend Engineer

deeply technical, hands-on role

scalable backend systems under real production load

Key Responsibilities

• Architect and implement

  reactive, non-blocking backend services

  in Java
• (Spring Boot WebFlux / Quarkus / Micronaut)
• Design and maintain

  REST and GraphQL APIs

  with strong performance and backward compatibility
• Build and own

  Node.js services

  for authentication, orchestration, and BFF layers
• Implement

  Saga patterns

  and compensating transactions for distributed financial workflows
• Design

  Apache Camel integrations

  using enterprise integration patterns and BPMN flows
• Optimize

  ORM usage

  (Hibernate / JPA / TypeORM) for performance, caching, and transaction safety
• Apply

  reactive programming paradigms

  (Project Reactor / RxJava) for high concurrency
• Design

  resilient systems

  using circuit breakers, retries, rate limiting, and fallbacks
• Lead

  code reviews, architecture discussions, and production incident resolution

• Mentor engineers and influence backend architecture standards

Required Skills (Non-Negotiable)

• 2-4 years of Backend developer experience ( For Junior Role )

• 6+ years of Backend engineering experience ( For Senior Role )

• Strong production experience with

  Java backend frameworks

·      Spring Boot (WebFlux preferred) / Quarkus / Micronaut

• Deep reactive programming experience

·      Project Reactor / RxJava / non-blocking I/O

• Strong

  Node.js

  experience for backend or middleware services
• Proven experience designing

  REST and GraphQL APIs at scale

• Strong GraphQL fundamentals:

·      Schema design

·      Resolver optimization

·      N+1 elimination

• Advanced

  ORM knowledge

·      Hibernate / JPA / TypeORM

·      Query tuning, caching, transaction management

• Experience with

  distributed systems

·      Saga pattern

·      Event-driven or async processing

• Strong

  database fundamentals

·      PostgreSQL / Oracle

·      Indexing, query plans, isolation levels

• Authentication & security knowledge:

·      OAuth2 / OIDC

·      JWT

• Production experience with:

·      Docker

·      Cloud platforms (AWS or Azure)

• Strong understanding of

  observability

·      Logs, metrics, tracing (Prometheus / ELK / Dynatrace / New Relic)

Good-to-Have (Strong Advantage)

• FinTech / retirement / regulated-domain experience
• Apache Camel in production
• Kafka / RabbitMQ / event streaming
• BPMN or workflow orchestration engines
• CQRS / Event Sourcing exposure
• API gateways, service mesh, platform engineering
• Chaos engineering or SRE practices

What We Are Looking For

• A

  true senior backend engineer

  , not just a feature developer
• Someone who has

  owned systems in production

• Strong bias toward

  performance, reliability, and correctness

• Comfortable working in

  audit-heavy, compliance-driven environments

• Mentors others and raises backend engineering standards

Work Mode

• Remote

Interview Process

• Deep backend fundamentals & architecture screening
• Reactive systems + API design discussion
• Distributed systems / Saga / failure-handling scenarios
• Code review or system-design round
• Final client/architect interaction (if required)

#Applicant can also mail their updated resume at aishwarya@mappoptimist.com