Founded in 2014, Circles is a global technology company reimagining the telco industry with its innovative SaaS platform, empowering telco operators worldwide to effortlessly launch innovative digital brands or refresh existing ones, accelerating their transformation into techcos.

Today, Circles partners with leading telco operators across multiple countries and continents, including KDDI Corporation, Etisalat Group (e&), AT&T, and Telkomsel, creating blueprints for future telco and digital experiences enjoyed by millions of consumers globally.

Besides its SaaS business, Circles operates three other distinct businesses:

• Circles.Life: A wholly-owned digital lifestyle telco brand based in Singapore, Circles.Life is powered by Circles’ SaaS platform and pioneering go-to-market strategies. It is the digital market leader in Singapore and has won numerous awards for marketing, customer service, and innovative product offerings beyond connectivity.

• Circles Aspire: A global provider of Communications Platform-as-a-Service (CPaaS) solutions. Its cloud-based Experience Cloud platform enables enterprises, service providers and developers to deliver and scale mobile, messaging, IoT, and connectivity services worldwide.

• Jetpac: Specializing in travel tech solutions, Jetpac provides seamless eSIM roaming for over 200 destinations and innovative travel lifestyle products, redefining connectivity for digital travelers. Jetpac was awarded Travel eSIM of the Year.

Circles is backed by renowned global investors, including Peak XV Partners (formerly Sequoia), Warburg Pincus, Founders Fund, and EDBI (the investment arm of the Singapore Economic Development Board), with a track record of backing industry challengers.

Role: Principal Engineer, Middleware Architecture & Integrations

Standardized Job Title: Principal Engineer, SRE Architecture

About this role

• Design, implement, and maintain highly available, scalable, and resilient middleware infrastructure — spanning messaging, caching, and integration layers — across AWS, GCP, and OCI as the primary platforms.
• Provide technical leadership and architectural expertise in middleware and integration engineering — covering event-driven architecture, message brokers, caching strategies, and API management frameworks.
• Lead middleware automation initiatives using Terraform, Ansible, and Python to drive zero-touch provisioning and configuration management across multi-cloud environments.
• Define and enforce SLOs, SLIs, and Error Budgets for middleware and integration services, ensuring throughput, latency, and reliability targets are met without compromising velocity.
• Architect and operate Kafka, RabbitMQ, and Redis platforms with a focus on scalability, cost optimisation, and fault tolerance.
• Own the API Gateway and integration strategy — designing secure, scalable, and well-governed APIs and event pipelines across internal and external systems.
• Collaborate with development and platform teams to embed reliability, security, and performance standards into integration design and the software delivery lifecycle.
• Lead incident response, post-mortem culture, and continuous improvement initiatives for middleware services to reduce MTTR and eliminate repeat failures.
• Ensure middleware design and operations align with regulatory, compliance, and data sovereignty requirements across cloud regions.
• Evaluate and adopt emerging middleware and integration technologies across AWS, GCP, and OCI to drive innovation and operational excellence.
  

What you'll do

• Design and architect resilient, scalable middleware infrastructure across cloud and hybrid environments with an integration-first mindset covering reliability, availability, and performance.
• Architect and operate Kafka clusters, RabbitMQ brokers, and Redis caching layers with focus on self-healing, auto-scaling, and platform resilience.
• Design, build, and govern API Gateways (e.g., Kong, Apigee, AWS API Gateway, Dell Bhoomi ) — covering routing, rate limiting, authentication, and traffic management for internal and external integrations.
• Develop and maintain infrastructure-as-code for middleware components using Terraform, Ansible, and Helm across AWS, GCP, and OCI environments — driving zero-touch provisioning and configuration management.
• Conduct performance tuning, capacity planning, and load testing on messaging and caching layers to proactively identify bottlenecks and ensure systems scale reliably under peak demand.
• Collaborate with development and platform teams to embed integration patterns, security, and operational standards into CI/CD pipelines and the software delivery lifecycle.
• Drive chaos engineering and resilience testing initiatives on middleware components to validate system behaviour under failure conditions and continuously harden the platform.
• Establish and enforce middleware best practices, runbooks, and playbooks — standardising operational procedures and reducing toil through automation.
• Mentor and upskill junior engineers on middleware architecture, event-driven design, and integration best practices to build long-term team capability.
  
  

What we are looking for

• 14+ years of overall experience with a minimum of 6 years in Middleware/Integration Architecture, operating in large-scale, high-availability, and mission-critical environments.
• Proven track record designing and operating distributed messaging systems — deep expertise in Apache Kafka (cluster design, partitioning, replication, schema registry) and RabbitMQ (exchanges, queues, clustering, HA).
• Understanding in Redis — caching strategies, cluster/sentinel topologies, persistence, and performance tuning at scale.
• Strong hands-on expertise with API Gateways (e.g., Kong, Apigee, AWS API Gateway, Azure APIM) — API lifecycle management, security, rate limiting, and traffic governance.
• Deep expertise in integration architecture — event-driven design, pub/sub patterns, ESB/iPaaS concepts, and third-party/partner (MNO, vendor) integrations.
• Strong hands-on expertise across AWS, GCP, and OCI — cloud-native architecture, hybrid cloud operations, and infrastructure optimisation at scale.
• Proficient in Infrastructure-as-Code and automation using Terraform, Ansible, and Helm — driving zero-touch provisioning, configuration management, and GitOps workflows.
• Expert in incident management and reliability operations for middleware — leading high-severity incident response, blameless post-mortems, RCA, and systematic elimination of repeat failures.
• Hands-on experience with chaos engineering and resilience validation — proactively testing failure modes and hardening messaging/caching systems against real-world degradation scenarios.
• Proven ability to lead, mentor, and grow architecture/engineering teams — establishing engineering standards, runbooks, playbooks, and a culture of operational excellence.
• Hands-on experience with project and delivery management tooling such as JIRA, with strong ability to manage priorities across concurrent integration initiatives.
• Outstanding analytical, problem-solving, and communication skills — ability to translate complex integration challenges into clear architectural decisions and stakeholder narratives.
  

Who you will work with

• Co-Founders and HODs
• Engineering Teams
• External customers/MNOs and vendors

Circles is committed to a diverse and inclusive workplace. We are an equal opportunity employer and do not discriminate on the basis of race, national origin, gender, disability or age.

Data Protection and Privacy Statement 

By submitting an application for this position, you, as the applicant, or your authorised representative(s), consent to Circles’ Candidate Data Protection and Privacy Policy. You also agree to the collection, use, and/or disclosure of your personal data by us solely for recruitment purposes as specified in the Policy. You acknowledge that you have read and understood the Policy, are aware of your rights regarding your personal data, and accept the terms relating to international data transfers, where applicable. You further understand that you may withdraw consent at any time, which may affect our ability to consider your application. In instances where your personal data or application is submitted by a third party, it is understood that such third party has been duly authorised by you to disclose the relevant personal data and provide consent on your behalf, and that you have been made aware of this Policy.

To all recruitment agencies: Circles will only acknowledge resumes shared by recruitment agencies if selected in our preferred supplier partnership program.

Please do not forward resumes to our jobs alias, Circles, employees or any other company location. Circles will not be held accountable for any fees related to unsolicited resumes not uploaded via our ATS.