Backend/Infra Engineer

Judgment Labs; San Francisco (CA); On-site; USD 140,000 - 180,000; Full time

Job summary

Judgment Labs is seeking a Senior Backend Engineer in San Francisco, CA. You will design and build high-throughput backend services that process agent telemetry efficiently. This role involves owning the API surface for our SDKs and dashboards while ensuring system scalability.

The ideal candidate has 6+ years of experience with backend systems, strong fundamentals in API design, and hands-on experience with OLAP databases like ClickHouse. You'll work with various technologies, optimizing performance while maintaining a high engineering quality standard.

Qualifications

• 6+ years of experience building and operating high-throughput backend systems.
• Fundamentals in API design and data modeling.
• Hands-on experience with OLAP databases like ClickHouse.

Responsibilities

• Design high-throughput backend services to process agent traces.
• Own the API surface for SDKs and dashboards.
• Tune the OLAP layer for performance optimization.

Skills

High-throughput backend systems

API design

Data modeling

Distributed systems

OLAP / columnar databases

Strong communication skills

Tools

ClickHouse

Kafka

Spark

Airflow

Job description

The Role

We're looking for a Senior Backend Engineer to own the services and APIs that power the data layer. You'll design the systems that ingest, evaluate, and serve agent telemetry at scale.

What You'll Do

• Design and build high-throughput backend services that ingest and process hundreds of thousands of agent traces per second.

• Own the API surface our SDKs and dashboards depend on: define contracts, manage versioning, and keep latency low under real customer load.

• Tune our OLAP layer (ClickHouse) through schema design, query optimization, and access-pattern analysis so reads stay fast as data grows to petabyte scale.

• Partner with the platform and infra teams on scalability, reliability, and the systems that back our evaluation and monitoring pipelines.

• Advocate for a high bar on backend and engineering quality: reliable, efficient, well-documented, testable, and maintainable.

What We're Looking For

• 6+ years of relevant industry experience building and operating high-throughput backend systems and services.

• Strong fundamentals in API design, data modeling, and the trade-offs of distributed systems under real production load.

• Hands-on experience with OLAP / columnar databases (ClickHouse, Presto) and a feel for how query patterns map to storage internals.

• Experience designing high-performance distributed systems.

• Comfort across the stack, with the breadth to reason about platform and infra decisions.

• Strong communication skills. You write clearly, review well, and make the people around you better.

Nice to Have

• Experience scaling pipelines that fan out to LLM APIs and managing the rate-limit, retry, and cost dynamics that come with them.

• Familiarity with streaming systems (Kafka, Spark, Flink, Ray) and ML orchestration tools (Airflow, Dagster, Prefect).

• Background in embedding / vector search infrastructure or data quality monitoring.

• Prior work on observability or developer-facing platform products.