Sr. Software Engineer – Backend / API Engineering

Ontrac Solutions; Chicago (IL); On-site; USD 140,000 - 200,000; Full time

Job summary

Ontrac Solutions is seeking a Senior Software Engineer (Backend/API) to lead greenfield backend services for a government licensing and regulatory platform on Google Cloud. You will own core domain services end to end, design APIs, and collaborate with client tech leads and cross-functional teams to deliver from definition to delivery.

The role emphasizes Java 21, Spring Boot, API governance, and secure, scalable cloud architectures.

Qualifications

• 8+ years of 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 for core domains (licensing, case management, payments, documents, notifications).
• Own the platform API surface, specify in OpenAPI and maintain stable contracts for mobile/frontend/integration teams.
• Build asynchronous event flows on Pub/Sub and Eventarc; implement persistence with AlloyDB and manage migrations.

Skills

Java

Spring Boot

GCP

API Design

PostgreSQL

Event-driven

OAuth 2.0 / JWT

CI/CD

Testing (JUnit)

Observability

Education

Bachelor's degree in Computer Science or equivalent

Tools

Cloud Run

Pub/Sub

Cloud Tasks

Cloud Scheduler

OpenAPI

PostgreSQL/schema design

Job description

OVERVIEW

We are seeking a highly skilled and experienced Senior Software Engineer (Backend / API) to join a contractor program supporting a critical customer engagement: a state government professional licensing and regulatory compliance platform built on Google Cloud. This is greenfield work - infrastructure, data and CI/CD are in place, and the application services are still to be built. This role is ideal for a senior backend engineer with deep Java and Spring Boot experience who owns core domain services end to end and designs the APIs the rest of the platform is built on. The successful candidate will build the licensing, case management, payments, document and notification services and the public and internal API surface, working closely with the client technical lead, the integration engineers, and the mobile and frontend engineers 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
• API design and ownership: REST, OpenAPI specification, versioning, pagination, error contracts, backward compatibility
• PostgreSQL, including schema design, indexing, query tuning, and versioned migrations
• GCP serverless services: Cloud Run, Pub/Sub, Cloud Tasks, Cloud Scheduler
• Event-driven architecture and messaging patterns (idempotency, retries, dead-letter handling)
• API security with OAuth 2.0 / OIDC and JWT, including role- and attribute-based authorization
• Automated testing (JUnit, integration tests) and CI/CD
• Observability of owned services: structured logging, metrics, tracing, SLOs

USEFUL QUALIFICATIONS

• Experience in government or regulated environments (FIPS, CJIS, HIPAA) - a plus, not a requirement
• Building APIs consumed by external partners, agencies, or public-facing applications
• AlloyDB, BigQuery
• Payment processing integrations and settlement reconciliation
• GraphQL or gRPC alongside REST
• Performance and load testing of high-traffic public services
• 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 for the core domain: licensing, applications and renewals, case management, payments, documents, and notifications
• Own the platform API surface - specify it in OpenAPI, keep contracts stable for the mobile, frontend and integration teams, and version changes without breaking consumers
• Implement PostgreSQL (AlloyDB) persistence, including row-level data isolation, search indexing, and migration strategy
• Build asynchronous event flows on Pub/Sub and Eventarc, and publish the domain events other services and the integration layer subscribe to
• Implement scheduled and timer-driven processing with Cloud Tasks and Cloud Scheduler (renewal reminders, expiration sweeps, reconciliation)
• Implement authentication and authorization across the API surface, including public applicant access and internal staff roles
• Implement payment flows, including hosted payment page integration and settlement reconciliation
• Meet platform security and compliance requirements for encryption, auditability, and data isolation
• Deliver unit and integration test coverage, participate in code reviews, and support CI/CD deployment of owned services