Staff Software Engineer – Distributed Systems

At Toku, we create bespoke cloud communications and customer engagement solutions to reimagine customer experiences for enterprises. We provide an end-to-end approach to help businesses overcome the complexity of digital transformation and deliver mission-critical customer experiences through cloud communication solutions. Toku combines local strategic consulting expertise, bespoke technology, regional infrastructure, connectivity, and global reach to serve enterprises operating at scale across APAC and beyond. With Toku B.V. now established in the Netherlands, we are expanding our European engineering presence and building out our team from our Rotterdam base.

As a Staff Software Engineer, you will be one of the most senior technical individual contributors within Toku Engineering, with significant autonomy to shape how our next generation of technology is designed and built. This is an opportunity to influence architecture and engineering direction across multiple squads while remaining deeply hands-on with complex software engineering challenges.

Toku is evolving and modernising significant parts of its technology estate. You will design and build systems from the ground up, modernise existing and legacy architecture, and help evolve our CCaaS, UCaaS and CPaaS capabilities towards a more unified and scalable platform. You will solve complex distributed-systems challenges involving high volumes of concurrent API requests, scalability, reliability and performance, with genuine scope to challenge existing approaches and introduce better ways of building software.

Working primarily across Go and Node.js, you will combine deep backend engineering and architecture with technical leadership, mentorship and influence across engineering. This is not a people-management role: you will lead through technical expertise, engineering judgement and the ability to help other engineers and teams solve difficult problems.

If you enjoy building systems at scale, modernising complex technology and having meaningful autonomy over architecture and engineering decisions, we'd love to hear from you.

What you will be doing

• Architecture & system design: Design new systems and services from the ground up, define architectural direction and make pragmatic technical decisions around scalability, performance, reliability, maintainability and long-term evolution.

• Distributed systems & scalability: Design and evolve distributed systems and microservices capable of handling high volumes of concurrent API requests and communication workloads, considering latency, resilience, fault tolerance, consistency and failure scenarios.

• Backend engineering: Remain deeply hands-on in the design, development and improvement of production backend systems, primarily using Go and

• Legacy modernisation: Lead the evolution of existing and legacy systems towards modern, scalable and maintainable architectures, balancing long-term technical direction with the realities of operating production software.

• Platform evolution: Help shape the longer-term evolution of Toku's technology towards a more unified platform architecture, identifying opportunities to create reusable capabilities, simplify architecture and reduce duplication across products and engineering squads.

• Event-driven systems: Design and evolve asynchronous and event-driven architectures using technologies such as Kafka, AWS SQS, RabbitMQ or similar messaging and event-streaming technologies.

• APIs & integrations: Design scalable APIs, service integrations and communication patterns across internal services, external providers and distributed backend systems.

• Cloud engineering: Design and operate cloud-native production systems, working within AWS and modern cloud environments to support reliable and scalable services.

• Engineering standards: Establish and improve engineering practices around software design, modularity, testing, code review, documentation, maintainability and continuous technical improvement.

• Production engineering & observability: Improve the reliability and operability of production systems through strong monitoring, observability, troubleshooting and performance-engineering practices.

• Technical leadership: Influence architecture and engineering decisions across squads, challenge assumptions constructively and help teams solve complex technical problems without relying on formal reporting authority.

• Mentorship: Develop other engineers through technical guidance, design and code reviews, pair programming, workshops and knowledge sharing, helping raise engineering capability across the organisation.

• Engineering improvement: Identify systemic technical problems, technical debt and inefficient engineering processes, and drive pragmatic improvements through automation, tooling, architecture and stronger engineering practices.

We’d love to hear from you if you have

• Staff-level engineering experience: Significant experience as a highly senior individual contributor, with the technical depth and judgement to influence architecture and engineering direction across multiple teams. Equivalent Staff, Principal, Architect or senior technical leadership experience is also welcome.

• Backend engineering depth: Extensive hands-on experience designing, building and operating complex production backend systems, with strong software-engineering fundamentals and a continued willingness to work directly with code.

• Go & : Strong practical backend engineering experience with Go and , or demonstrably deep expertise in comparable backend technologies with the ability to work effectively across a polyglot environment.

• Architecture & system design: Proven experience designing complex systems from the ground up and making architectural decisions around scalability, high-volume API traffic, reliability, performance and maintainability.

• Distributed systems: Deep understanding of distributed systems, microservices and the challenges associated with operating them at scale, including resilience, concurrency, fault tolerance and failure handling.

• Legacy modernisation: Experience taking existing or legacy systems and evolving them towards cleaner, more scalable and maintainable architectures.

• Event-driven architecture: Practical experience with Kafka, AWS SQS, RabbitMQ or comparable event-streaming and messaging technologies, with a strong understanding of asynchronous system design.

• APIs & integrations: Strong experience designing production APIs and service integrations, including the architectural considerations involved in operating APIs at scale.

• Cloud engineering: Strong experience building and operating software in public cloud environments. AWS experience is advantageous, but strong experience with Azure or GCP is also relevant.

• Engineering craft: Strong understanding of maintainable software design, automated testing, code quality and modern engineering methodologies. Experience with architectural patterns and practices such as Domain-Driven Design, CQRS, Saga or similar approaches is advantageous.

• Production & observability: Strong experience operating production systems and using monitoring, logging, metrics and tracing to understand behaviour, diagnose problems and improve reliability. Experience with tools such as Grafana, Prometheus, OpenTelemetry, Datadog or similar is beneficial.

• Technical leadership & influence: A track record of setting technical direction, mentoring experienced engineers, raising engineering standards and influencing teams through technical credibility rather than formal authority.

• Ownership & autonomy: The ability to take ambiguous and complex engineering problems, establish direction and drive them through to pragmatic, sustainable solutions.

• Broader technical environment: You will work alongside infrastructure and engineering teams operating technologies and practices including Docker, Kubernetes, Terraform, Terragrunt, Infrastructure as Code, CI/CD and GitOps. Previous hands-on expertise across these technologies is not a requirement for this role, although relevant exposure is naturally advantageous.

• Authentication & security (nice to have): Familiarity with modern authentication approaches such as JWT, OAuth2 and OIDC, or experience integrating with identity and access-management systems such as Keycloak.

• Communications domain (nice to have): Experience with CPaaS, CCaaS, UCaaS, messaging, voice, telephony or other high-volume communications platforms would be advantageous.

• Location: This role is to be based in The Netherlands (Hybrid). We are open to considering other EU country based candidates, who are willing to relocate to The Netherlands, now or in the future.

Toku has been recognised as a LinkedIn Top Startup and by the Financial Times as one of APAC’s Top 500 High Growth Companies. If you’re looking to be part of a company on a strong growth trajectory while working on meaningful, real-world challenges, we’d love to hear from you.