Senior Backend Developer

TechDigital Group; California (MO); Hybrid; USD 90,000 - 120,000; Full time

Job summary

TechDigital Group is seeking a Senior Backend Developer to enhance their core platform, focusing on federated authentication and vehicle management systems. The candidate will design and implement new domain entities, refactor existing schemas, and integrate Firebase Authentication.

Key responsibilities include developing API layers and managing complex data relationships. Strong experience in backend development is essential, particularly with Java/Spring Boot frameworks.

Qualifications

• Strong experience in backend development using Java/Spring Boot or similar frameworks.
• Proven expertise in REST API design and refactoring.
• Experience implementing middleware components.

Responsibilities

• Design and implement new domain entities to support federated identity mapping.
• Refactor existing schemas to separate vehicle-level and profile-level concerns.
• Integrate Firebase Authentication and validate ID tokens.

Skills

Backend development (Java/Spring Boot)

REST API design

Relational database design

Authentication/authorization frameworks (JWT, OAuth)

Job description

Role Summary

We are seeking a Senior Backend Developer to design, implement, and refactor core platform services supporting federated authentication and a multi-entity vehicle management system. This role focuses on integrating Firebase-based identity, restructuring backend data models, and modernizing API layers to support scalable account, vehicle, and profile relationships.

Key Responsibilities

1. Data Model & Persistence Layer

   • Design and implement new domain entities including user_account and vehicle_profile to support federated identity mapping.
   • Refactor existing schemas (e.g., vehicle_enrollment) to separate vehicle-level and profile-level concerns.
   • Develop and execute database migrations, including:
     • Table creation, column restructuring, and foreign key repointing
     • Index updates and performance optimizations
   • Implement data backfill and reconciliation logic for existing records, including consolidation of vehicle and profile relationships.

2. API & Middleware Development

   • Refactor REST APIs to support:
     • Account-level, vehicle-level, and profile-level operations
     • Updated relationships between entities (account to vehicles to profiles)
   • Implement cross-cutting concerns:
     • Request interceptors/filters for authentication and context resolution
     • Shared request context updates (vehicleProfileId, userAccountId)
   • Enhance API contracts, OpenAPI documentation, and error handling to reflect new data model and authentication patterns.

3. Authentication & Security Integration

   • Integrate Firebase Authentication and implement ID-token validation and claim extraction.
   • Transition from client-credential-based authentication (e.g., Keycloak) to federated identity model.
   • Implement account-ownership authorization to enforce access control across account, vehicle, and profile scopes.

4. Service Layer & Business Logic

   • Rework service logic to support:
     • Vehicle enrollment and profile creation flows
     • Signing key management and rotation
     • Payment/card binding at profile level
   • Update transaction processing logic to distinguish between:
     • Profile-based signed transactions
     • Vehicle-level fallback scenarios
   • Implement account-level operations such as:
     • Full account closure with cascading vehicle unenrollment and partial failure handling

5. Integration & External Systems

   • Work with third-party integrations including:
     • Firebase (identity provider)
     • Client SRC (card tokenization and identity binding)
     • Payment middleware and BOS systems
   • Ensure consistency of entity mapping across internal services and external callbacks.

6. Testing & Quality Engineering

   • Develop and execute integration and regression test plans across:
     • Updated schema and foreign key relationships
     • API endpoints and authentication flows
   • Update test teardown and data lifecycle logic to reflect new entity relationships.

Required Qualifications

• Strong experience in backend development (Java/Spring Boot or similar frameworks)
• Proven expertise in:
  • REST API design and refactoring
  • Relational database design, schema migrations, and indexing
  • Authentication/authorization frameworks (JWT, OAuth, federated identity)
• Experience implementing middleware components such as interceptors, filters, and request contexts
• Familiarity with cloud-based identity providers (e.g., Firebase Auth, OAuth providers)

Preferred Qualifications

• Experience with payment systems and tokenization (e.g., Client SRC or similar)
• Prior work on multi-tenant or hierarchical data models (account to asset to profile)
• Knowledge of event-driven integrations and callback-based third-party systems
• Experience with API gateways and distributed security validation patterns

Key Competencies

• Strong system design and data modeling skills
• Ability to manage complex refactoring across multiple layers (DB, API, service)
• Attention to data integrity, security, and backward compatibility
• Effective collaboration across architecture, QA, and integration teams

Scope & Impact

• End-to-end ownership of a major platform refactor spanning:
  • Data model redesign
  • Authentication transformation
  • API and service re-architecture
• Direct impact on enabling scalable, multi-vehicle, multi-profile user experiences
• Critical role in aligning platform architecture with federated identity standards and payment constraints