# Principal Software Engineer
**Company:** [ZoomInfo](https://hotfix.jobs/companies/zoominfo)
**Location:** Waltham, MA
**Salary:** $164K-$257K
**Experience:** 5+ years
**Skills:** Java, Go, Python, SQL, Kafka, Kinesis, ClickHouse, DynamoDB, LangGraph, LLMs
**Posted:** 2026-02-04
> Designs and builds distributed systems, high-performance APIs, and LLM-powered features for ZoomInfo's real-time B2B marketing platform. Requires 5+ years in backend/data engineering with expertise in distributed systems, big data, or applied AI/ML.
## Job Description
## What You’ll Do

- Design and build distributed systems that process, enrich, and respond to billions of behavioral events per day in real time
- Develop high-performance APIs and services that support advertising, identity, and intent features across the Marketing Platform
- Leverage machine learning and large language models (LLMs) to analyze behavioral data, classify content, extract signals, and enable intelligent decision-making
- Build intelligent agents using frameworks like **LangGraph** or MCP to reason over data and power user-facing insights
- Design and operate data pipelines using tools like **Kafka**, **Kinesis**, and **ClickHouse** to support both streaming and batch workloads
- Drive quality, performance, scalability, and observability across all systems you own
- Collaborate cross-functionally with product managers, data scientists, and engineers to deliver customer-facing features and internal tooling
- Contribute to technical leadership and mentorship of teammates

## What We’re Looking For

- **5+ years** of backend, data, or infrastructure engineering experience, or equivalent impact and leadership
- Strong experience in at least one of the following:
  - **Distributed systems engineering** (e.g., building low latency high throughput APIs, scalable microservices, event processing pipelines)
  - **Big data infrastructure** (e.g., streaming, warehousing, low-latency storage at scale)
  - **Applied AI/ML**, including use of LLMs for extraction, classification, or reasoning tasks
- Proficiency in one or more core languages: **Java**, **Go**, **Python**
- Solid grasp of **SQL** and large-scale data modeling
- Familiarity with databases and tools such as: **ClickHouse**, **DynamoDB**, **Bigtable**, **Memcached**, **Kafka**, **Kinesis**, **Firehose**, **Airflow**, **Snowflake**

### AI-Native Development Mindset

- Comfortable using LLMs as part of your development workflow—whether via tools like Copilot, Cursor, ChatGPT, Claude, or others—to boost productivity, explore architecture ideas, and rapidly prototype
- Skilled at designing and implementing LLM-powered systems such as RAG pipelines, agent frameworks (e.g., **LangGraph**), or intelligent workflows that reason across large datasets in real time

### Bonus Points

- Experience in ad tech, real-time bidding (RTB), or programmatic systems
- Background in identity resolution, attribution, or behavioral analytics at scale
- Contributions to open source in ML, infrastructure, or data tooling
- Strong product instincts and a passion for building tools that drive meaningful outcomes
**Apply:** https://hotfix.jobs/jobs/principal-software-engineer-at-zoominfo-fcbb3e83-173d-4fcc-a41e-97331e026482
**Canonical:** https://hotfix.jobs/jobs/principal-software-engineer-at-zoominfo-fcbb3e83-173d-4fcc-a41e-97331e026482