Sr. Software Engineer – Backend Engineering (Core) / Integrations

Ontrac Solutions; Chicago (IL); On-site; USD 140,000 - 190,000; Full time

Job summary

Ontrac Solutions in Chicago seeks a Senior Software Engineer (Backend / Integrations) to design and build Java-based microservices on Google Cloud, integrating with external systems via REST, SOAP and SFTP.

You will work with client tech lead and cross-functional teams to deliver core platform services, with emphasis on security, testing, and CI/CD, starting 5 October 2026.

Qualifications

• 8+ years of professional backend engineering experience with Java and Spring Boot.
• Production delivery experience on Google Cloud Platform.
• Bachelor's degree in Computer Science or equivalent practical experience.

Responsibilities

• Design and implement Java 21 / Spring Boot microservices on Cloud Run (licensing, case management, payments, documents, notifications).
• Implement PostgreSQL (AlloyDB) persistence, including row-level data isolation and search indexing.
• Build asynchronous event flows on Pub/Sub and Eventarc.
• Implement scheduled processing with Cloud Tasks and Cloud Scheduler.
• Author Cloud Workflows orchestrations for multi-service pipelines.
• Build integrations with external state and federal systems over REST, SOAP, SFTP, and webhooks.
• Implement payment flows, including hosted payment page integration and settlement reconciliation.
• Meet platform security and compliance requirements for encryption and data isolation.
• Deliver unit and integration tests, participate in code reviews, and support CI/CD deployment.

Skills

Java 21

Spring Boot 3.x

PostgreSQL

GCP

REST

SOAP

SFTP

OAuth 2.0/OIDC

JWT

Event-driven microservices

JUnit/Integration tests

CI/CD

Cloud Run

Pub/Sub

Cloud Tasks

Cloud Workflows

Education

Bachelor's degree in Computer Science

Tools

AlloyDB

BigQuery

Job description

OVERVIEW

We are seeking a highly skilled and experienced Senior Software Engineer (Backend / Integrations) to join a contractor program supporting a critical customer engagement: a state government professional licensing and regulatory compliance platform built on Google Cloud. This role is ideal for a senior backend engineer with deep Java experience who builds event-driven microservices and has integrated with external systems over REST, SOAP, and SFTP. The successful candidate will build core platform services and the external integration layer, working closely with the client technical lead, the mobile and frontend engineers, and customer stakeholders to ensure project success from initial definition through final delivery.

Expected start date: 5 October 2026.

REQUIRED CREDENTIALS

• 8+ years of professional backend engineering experience with Java and Spring Boot
• Production delivery experience on Google Cloud Platform
• Bachelor's degree in Computer Science or equivalent practical experience

REQUIRED QUALIFICATIONS

• Java 21 and Spring Boot 3.x microservice development
• PostgreSQL, including schema design, indexing, and versioned migrations
• GCP serverless services: Cloud Run, Pub/Sub, Cloud Tasks, Cloud Workflows, Cloud Scheduler
• Event-driven architecture and messaging patterns (idempotency, retries, dead-letter handling)
• External system integration over REST, SOAP, SFTP, and webhooks
• API security with OAuth 2.0 / OIDC and JWT
• Automated testing (JUnit, integration tests) and CI/CD

USEFUL QUALIFICATIONS

• Workflow engines (Flowable, BPMN) and business rules engines
• AlloyDB, BigQuery
• Payment processing integrations
• Experience in government or regulated environments (FIPS, CJIS, HIPAA)
• Google Cloud Professional certifications

SCOPE AND SOLUTION EXPECTATIONS

Below covers the scope of work we anticipate the contractor supporting throughout the project timeline.

• Design and implement Java 21 / Spring Boot microservices on Cloud Run (licensing, case management, payments, documents, notifications)
• Implement PostgreSQL (AlloyDB) persistence, including row-level data isolation and search indexing
• Build asynchronous event flows on Pub/Sub and Eventarc
• Implement scheduled and timer-driven processing with Cloud Tasks and Cloud Scheduler (renewal reminders, expiration sweeps, reconciliation)
• Author Cloud Workflows orchestrations for multi-service pipelines
• Build integrations with external state and federal systems over REST, SOAP, SFTP, and webhooks
• Implement payment flows, including hosted payment page integration and settlement reconciliation
• Meet platform security and compliance requirements for encryption and data isolation
• Deliver unit and integration test coverage, participate in code reviews, and support CI/CD deployment of owned services