Senior Java developer

##### **Project description**

Modernization project for the core business systems of a major US airline.

##### **Responsibilities**

Design and implement a rules engine in Java 17\+ that evaluates events against parameterized, effective\-dated rules

Implement rules as code: versioned, parameterized, valid for defined effective\-date ranges, with a clear explanation of every evaluation result

Build robust date and time logic: time zones, DST transitions, rolling windows, and cumulative limits

Develop event\-driven services on Kafka (Amazon MSK) that consume events, evaluate rules, and publish alerts, with guaranteed ordering, idempotency, and replay

Work with the rule and parameter repository and cumulative\-limit state in PostgreSQL (Aurora), together with data engineers

Write clean, testable domain code with thorough automated tests of rule behavior

Build services that handle high, bursty volume (over 1M checks per day)

Support parallel runs and parity checks against the legacy system

Instrument services with metrics, tracing, and structured logs, and work with DevOps on deployment to AWS

##### **Skills**

Must have

5\+ years of commercial backend development in Java, with hands\-on use of Java 17\+ features (records, sealed interfaces, pattern matching, switch expressions)

Strong domain modeling skills, keeping business logic clean, testable, and separate from infrastructure (DDD / hexagonal architecture)

Expert knowledge of java.time

Instant vs. ZonedDateTime vs. LocalDateTime

Time zones and DST transitions

Duration and Period arithmetic

Interval and rolling\-window calculations

Proven experience implementing complex business rules directly in code (not by configuring a commercial BRMS such as IBM ODM, FICO Blaze, or Pega):

Parameterized and effective\-dated rules

An auditable explanation or trace for every result

Production experience with Apache Kafka

Producers and consumers, consumer groups

Partitioning and keys for ordering

Offset management and replay

Idempotent processing and delivery semantics

Solid SQL and relational database experience, preferably PostgreSQL (schema design, transactions, query optimization)

Testing

JUnit 5 and parameterized tests

Testing time\-dependent logic deterministically, e.g., with an injectable Clock

Git, code review practices, and working with CI pipelines

Ability to work independently with a strong problem\-solving mindset

Nice to have

Temporal and versioned data modeling in PostgreSQL/Aurora: effective\-date ranges (range types, exclusion constraints), bitemporal models

Running Java services on AWS: ECS Fargate, Lambda, API Gateway, plus working knowledge of IAM, Secrets Manager, and KMS

DynamoDB, and ElastiCache (Redis/Valkey) for caching

Observability: Micrometer and/or OpenTelemetry, distributed tracing, structured logging, latency percentiles (p95/p99\)

High\-volume, low\-latency services: bursty load, back\-pressure, concurrency, JVM performance tuning

Embedded expression languages and runtime configuration (changing rule parameters without redeployment)

Familiarity with S3, Athena, Glue, or Firehose for reporting pipelines

Legacy system replacement: parallel runs, parity and accuracy validation

Domain experience in crew or workforce scheduling, or in duty and rest time compliance

##### **Other**

Languages

English: B2 Upper Intermediate

Seniority

Senior

Remote India, India

Req. VR\-125535

Java

Cross Industry Solutions

02/11/2026

Req. VR\-125535