Responsible for developing and maintaining the Core Identity Services (CIS) and the Master Database for the USKids project. CIS acts as the single source of truth for customer identity across multiple independent services.
This role works across both back-end and front-end to build identity features, integrate data sources, and ensure data is consolidated, accurate, and consistent across systems.
The developer will work alongside the existing team member on CIS and take part in designing and building the Master Database as the project progresses.

1. Core Identity Services (CIS) Development & Maintenance
 Develop and maintain CIS back-end services on Cloud Run (Node.js), including the read/write API, ingest API, notifier, and reverse-ETL / sync jobs.
 Design and implement the REST API (persons, consent, service-data, privacy, service registry) following the API contract — idempotency, optimistic concurrency (versioning), field-level ACLs, and RFC 9457 problem responses.
 Implement authentication and authorization for service-to-service traffic (Google OIDC ID tokens, RS256 service JWTs, scopes) and enforce field ownership rules
(AUTHORED / DERIVED / LEDGERED).
 Build the webhook fan-out and delivery mechanism (HMAC-signed webhooks, retries, dead-lettering, at-least-once delivery, coalescing).
2. Customer Data Lake & Identity Resolution
 Build and maintain the ingestion pipeline (per-source connectors, Pub/Sub, BigQuery bronze/silver/gold) with an at-least-once, idempotent, append-only bronze layer.
 Implement and evolve the identity-resolution logic in BigQuery SQL / Dataform: normalisation of identity keys, matching, clustering (connected components), and survivorship to compute the golden record.
 Author Dataform SQL models, assertions, and lineage; maintain silver/gold transforms.
 Implement source connectors and the transactional outbox / reconciliation patterns for owned services (Tournament, Player Pathway) and SaaS sources (Shopify, Klaviyo).

3. Data Model, Databases & Data Quality
 Design and maintain the Cloud SQL PostgreSQL serving schema, using constraints,
triggers, row-level security, and cascade deletes to enforce invariants at the
database level.
 Write, optimize, and maintain efficient SQL across both PostgreSQL and BigQuery; troubleshoot slow queries and apply indexing and partitioning.
 Ensure data consistency, integrity, deduplication, provenance, and quality across the lake and the serving tier.
 Support data migration and backfill, schema evolution, and retention/partitionexpiration requirements as the project grows.

3. Integration, Infrastructure & Collaboration
 Integrate with third-party platforms (Shopify Admin/GraphQL, Klaviyo REST) via the reverse-ETL and sync jobs.
 Work with GCP building blocks — Cloud Run, Cloud SQL, BigQuery, Pub/Sub, Cloud Storage, Secret Manager, IAM — and support IaC (Terraform) and CI/CD (GitHub Actions).
 Work closely with the existing CIS team member and other developers to deliver features end to end, participate in estimation, technical discussions, and code reviews.
 Write clean, maintainable, well-documented code and communicate progress, blockers, and risks clearly with the team.Skills & Qualifications

4. Must-have
 Bachelor's degree in Computer Science, Software Engineering, Information Systems, or a related field.
 Solid experience as a full-stack or back-end-focused developer building and maintaining production web services and APIs.
 Strong proficiency in JavaScript/TypeScript and Node.js (Express, NestJS, or equivalent) for building back-end services.
 Strong knowledge of relational databases (PostgreSQL preferred) and SQL, including schema design, constraints, indexing, transactions, and query optimization.
 Experience designing and building RESTful APIs, including versioning, idempotency, pagination, and error handling.
 Solid understanding of authentication and authorization concepts (OIDC, OAuth2, JWT, scopes, service-to-service auth) and secure API practices.
 Experience with data integration / consolidation across multiple sources, and with SQL-based data transformation.
 Understanding of messaging / event-driven patterns (pub-sub, at-least-once delivery, idempotency, outbox pattern, webhooks).
 Careful, responsible, and detail-oriented, especially regarding data accuracy, consistency, and security.
 Ability to read and understand technical design documents and communicate in English.
Nice-to-have
 Hands-on experience with Google Cloud Platform (Cloud Run, Cloud SQL, BigQuery, Pub/Sub, Cloud Storage, Secret Manager, IAM).
 Experience with BigQuery and a SQL transformation framework (Dataform or dbt).
 Experience with identity resolution / entity matching / master data management (deduplication, survivorship, record linkage a plus).
 Experience building or maintaining a data lake, data warehouse, or customer/golden-record platform.
 Experience integrating third-party platforms such as Shopify and Klaviyo (webhooks, HMAC verification, reverse ETL). Experience with Terraform, GitHub Actions, and containerized deployments (Docker).
 Awareness of data-privacy and consent requirements (e.g. TCPA/CCPA, perpurpose consent, deletion/retention).
 Experience working in a software company, outsourcing company, or an environment with multiple client projects.
 Interest in or experience with the sports/golf industry is a plus.

Trong tuần: Từ thứ 2 - thứ 6

Trong ngày: Từ 08:30 giờ - 17:30 giờ

Opportunities to onsite and work with big customers, advanced technology, personal development...
- Opportunity to work in groups with many leading experts in the field of domestic and international IT.
- Opportunity to implement ambitious projects in many countries, gain exposure to the latest technologies and learn from talented colleagues.
- Work in a youthful, vibrant, modern and multicultural environment. Communication activities and events on holidays take place regularly.
- Promotion opportunities based on capacity with corresponding rank increases and salary increases.
- Have the right to participate in soft skills training courses (logical thinking, creative thinking, communication skills, project management skills, negotiation skills...) and Japanese language classes.
- And many other attractive benefits...

Onsite Dương Đình Nghệ, HN