Software Engineer I/II (AI Platform)

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.

About the Role

The Platform AI team builds the AI platform behind Circles' product experiences. This role sits at the intersection of backend and AI engineering — ideal for someone who enjoys shipping production software and has hands-on experience with LLM-powered, agentic systems. You'll build core platform capabilities, distributed backend services, and AI-driven workflows that power reliable, scalable, and secure product experiences.

What You'll Do Design and implement cross-repository features, including API contracts, database schemas, and migrations.

Build backend services that support AI-powered workflows and platform capabilities.

Develop and maintain LLM-enabled features and agentic workflows across a distributed system.

Write maintainable, well-tested code with strong performance and security practices.

Troubleshoot and resolve production issues across distributed services.

Partner with product and engineering stakeholders to deliver reliable user-facing systems.

Mentor SDE-1 engineers — breaking down epics, pairing on complex changes, and improving documentation.

What We're Looking For 1–5 years building, shipping, and maintaining production backend or platform software.

Strong Python experience, especially with async FastAPI.

Hands-on experience with LLM APIs or other AI-powered application features.

Solid grasp of distributed systems fundamentals: HTTP, caching, database consistency, streaming, and failure modes.

Advanced experience with MongoDB or a similar document database — indexing, schema changes, and query optimization.

A habit of contributing unit, integration, and contract tests.

Clear written communication for RFCs, merge request descriptions, and incident postmortems.

Ability to pick up Go or another production language when the work calls for it.

Curious to learn new things on AI and building on top of it.

Familiar with using coding agents like cursor, codex, claude code.

AI Skills We Expect LLM application development — shipping production features with LLM APIs, including prompt design, tool/function calling, structured outputs, and robust response handling.

Agentic systems — building or maintaining multi-step, stateful agent workflows, ideally with supervisor/worker patterns.

Tool integration — wiring external tools and services into AI systems through backend orchestration and MCP-style tool access.

Evaluation and quality — assessing AI behavior with regression cases, golden datasets, human review, and failure analysis.

Streaming and latency — delivering responsive experiences with streaming output and graceful degradation.

Safety and privacy — guarding against prompt injection, data leakage, and PII exposure.

Observability — instrumenting AI features with logs, traces, metrics, and feedback loops.

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.