Senior Software Engineer - MERN Stack

Software Engineer (API Integration & Platform Development)

Locaria is a global localisation and multilingual content company, part of the Stagwell network, helping brands adapt and scale their content across languages and markets. Adaptria is Locaria's proprietary platform: a comprehensive operational ecosystem covering the client portal, client and vendor databases, project and workflow management, and billing. We are looking for a Software Engineer with strong API integration experience to support the ongoing development and evolution of Adaptria. Working as part of our engineering team and closely with Product, you will play a key role in enhancing the platform and expanding its integrations.

Key Responsibilities

• Feature delivery: Deliver new features, enhancements, and bug fixes across the stack, from database schema through to the web application and the public API.
• API development & integrations: Develop and implement API integrations between the platform and internal and third-party SaaS systems, and extend the platform's public API.
• System design & architecture: Design scalable, reliable, and secure services and infrastructure, applying solid API design principles such as versioning, security, and performance.
• Workflow automation: Build and maintain event-driven services and scheduled jobs that automate workflows across connected systems.
• Technical direction: Help steer the technical direction of the platform alongside the engineering team and Product.
• Documentation: Produce clear, comprehensive documentation of system architecture, integrations, workflows, and implementation details.
• Team growth: Help grow the in-house technology function by recruiting, mentoring, and line managing junior engineers as the team expands, fostering technical best practices and knowledge sharing.
• You will work with both technical and non-technical stakeholders, so you should be able to explain complex technical concepts clearly and build strong working relationships across the business.

Required Skills & Qualifications

• Cross-functional teamwork: Proven ability to work effectively across teams and departments in a collaborative, partnership-driven environment.
• System design: Good understanding of designing and building scalable, reliable, and secure systems.
• Backend development: Strong professional experience with TypeScript and Node.js building backend services and REST APIs.
• Frontend development: Solid JavaScript/TypeScript, HTML, and CSS, with working experience in React (ideally Next.js).
• API integration: Strong knowledge of API design and implementation using REST, with familiarity with authentication methods such as OAuth2 and JWT, and experience with OpenAPI/Swagger. WebSockets a plus.
• Databases: Strong understanding of relational databases, especially PostgreSQL, including schema design and migrations.
• Cloud platform expertise: Proficiency with Google Cloud Platform.
• Event-driven & workflow automation: Hands-on experience with message brokers or event-driven architectures (for example NATS, Kafka, or RabbitMQ) and scheduled/background jobs.
• Containerisation: Experience with Docker for containerisation and Kubernetes for container orchestration.
• CI/CD & version control: Familiarity with CI/CD pipelines and tools, especially Git and GitHub Actions.
• Good to have (nice to have)
• Microservices frameworks such as Moleculer, and dependency injection with InversifyJS or similar (class-based OOP with decorators).
• Type-safe ORMs such as Drizzle ORM, and Zod for schema validation.
• Frontend tooling we use: TanStack Query, react-hook-form, TailwindCSS, Radix UI, and component-driven development with Storybook.
• Building and documenting a public API and developer-facing docs; exposure to API-first or MCP-style tooling.
• Infrastructure-as-code with Terraform, and running workloads on Google Kubernetes Engine.
• Observability tooling: OpenTelemetry, Grafana/Loki, Sentry.
• End-to-end testing with Playwright; Nx monorepo and pnpm workspaces.
• Python for scripting and automation (Flask or FastAPI a plus).

Ideal

Experience with translation technologies such as Phrase, Plunet, XTRF, Trados, XTM, or MemoQ, and knowledge of the translation industry and localisation workflows.

What we offer

• Mentorship and Training: Mentorship and training programs tailored to help you grow across multiple engineering disciplines.
• An AI-native workflow: you'll learn to leverage AI tools as part of your daily engineering practice, not as an afterthought.
• Career Development: Opportunities for career advancement and professional growth.
• Collaborative Environment: A supportive and collaborative work environment where your contributions are valued.
• Learn and Excel: Continuous learning opportunities to keep your skills sharp and current.