Platform Engineer, APIs & Observability

StackAI; Warszawa; On-site; PLN 80,000 - 100,000; Full time

Job summary

StackAI is looking for a Platform Engineer for APIs & Observability in Warsaw, Poland. The role involves designing and evolving the public API, defining standards, and building observability tools. Candidates should have 4+ years of experience in backend services and public APIs.

Join a high-impact team that values diversity and offers fast-paced work. Ideal candidates are proficient in Python and experienced with distributed tracing and analytics.

Qualifications

• 4+ years building backend services and public APIs in production.
• Strong API craft skills in RESTful design and SDK ergonomics.
• Fluency with observability and analytics, distributed tracing, and metrics.
• Experience with Python and modern backend frameworks like FastAPI.

Responsibilities

• Design, version, and evolve the public API and SDKs.
• Define API standards, conventions, and review processes.
• Build tracing and instrumentation for observability.
• Create reporting for customer agent performance and improvement.
• Develop audit logging and views for enterprises.

Skills

Backend services and public APIs

API craft: RESTful design

OpenAPI experience

Distributed tracing and metrics

Fluent in Python

TypeScript/Node.js

Job description

About StackAI

StackAI is a no-code platform for designing, testing, and deploying AI workflows powered by large language models. Our visual, drag-and-drop interface lets teams connect their data to AI models and ship production applications — from chatbots to document-processing pipelines to database Q&A tools — without writing code.

The role

Every developer who builds on StackAI works through your API, and every customer who wants to understand what their agents are doing relies on the analytics you build. We're hiring a Platform Engineer, APIs & Observability to own both: the public API the ecosystem builds on, and the observability and analytics that make a platform full of autonomous agents understandable.

This is high-leverage, highly visible work. The API is the contract every integration depends on, and observability for multi-step, multi-model agent runs is a hard, interesting problem. You'll own the surfaces developers and customers use every day.

What you'll do

• Help build the public API as a product. Design, version, and evolve the API and SDKs that StackAI customers build on, and keep the developer experience first-class.

• Set our API standards. Help define the conventions, versioning and deprecation policy, and review bar that keep every API across the platform consistent and predictable.

• Make agent runs observable. Build tracing and instrumentation that let anyone follow a single agent run end to end, across its models, tools, and sub-agents.

• Turn usage into analytics customers act on. Build the reporting that shows customers how their agents perform, what they cost, and where to improve.

• Own the audit trail. Build the audit logging and team-scoped views enterprises rely on.

What we're looking for

• 4+ years building backend services and public APIs in production.

• Strong API craft: RESTful design, SDK ergonomics, and rate limiting.

• You speak fluent OpenAPI — experience defining API standards and governance: versioning, deprecation, and consistency across services.

• Fluency with observability and analytics: distributed tracing, metrics, and turning raw signals into data products people rely on.

• Strong in Python and modern backend frameworks (FastAPI or similar), comfortable across TypeScript/Node.js on the product surfaces.

Platform engineering is broad. If you're strong on most of this and excited to grow into the rest, we'd like to hear from you, even if you don't check every box.

Bonus points

• OpenTelemetry or distributed tracing at scale.

• Analytics datastores (ClickHouse, Druid, or similar).

• Designing developer-facing SDKs used by external customers.

• AI or LLM platform experience: token and cost accounting, agent-run tracing.

• Startup or growth-stage experience.

Why StackAI

You'll join a lean, high-impact team and own the surfaces developers and customers touch every day. Your work ships fast and is felt across the whole product.

StackAI is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.