Senior Software Engineer - Backend, Data Products - MarTech/AdTech

Three Pillars Recruiting; San Francisco (CA); On-site; USD 180,000 - 230,000; Full time

Job summary

Three Pillars Recruiting in San Francisco is seeking a Senior Software Engineer - Backend, Data Products who will build the composable, self-correcting pipelines customers rely on and shape the backend/GraphQL surface. You will implement Reactors, connectors, and validation, collaborate with product and data science in sprint cycles, and help scale ETL/ELT workflows for real-world data.

This role emphasizes robust design, observable systems, and performance, with modern Python, Temporal/NATS,

Qualifications

• 5+ years writing production software with modern Python.
• Experience designing APIs using GraphQL and/or REST.
• Experience building and validating data pipelines at scale.
• Strong PostgreSQL schema design and query optimization.

Responsibilities

• Build and extend Reactors to enable composable pipelines.
• Develop connectors, ingestion, and transformation tooling for diverse data sources.
• Incorporate data validation and quality checks into pipelines (e.g., contract-style checks).
• Design and ship the backend/GraphQL surface for pipeline capabilities.
• Orchestrate multi-step pipeline work with Temporal and event-driven systems (NATS/Kafka).
• Collaborate in sprint cycles with product and data science to productionize analytics.

Skills

Python

GraphQL

Pandas

SQLAlchemy

Async/await

Pydantic

Tools

Temporal

NATS

Kafka

REST

Job description

Senior Software Engineer - Backend, Data Products

As a Senior Software Engineer on Backend, Data Products, you build the product itself - the composable, self-correcting pipeline capabilities customers actually use. You develop Reactors (the Observe / Match / Act / Compose primitives at the heart of the platform), the connectors and tooling that bring messy real-world data in, the validation that keeps it trustworthy, and the backend/GraphQL surface that exposes it. This is applied backend engineering: turning a hard product vision into resilient, shippable features.

What You’ll Do

• Build and extend Reactors — the Observe / Match / Act / Compose primitives that make pipelines composable and self-correcting.
• Develop connectors, ingestion, and transformation tooling for diverse, messy marketing data sources, including schema evolution.
• Build data validation and quality into the pipeline (e.g., Great Expectations-style contracts) so correctness is enforced, not hoped for.
• Design and ship the backend / GraphQL surface that exposes pipeline capabilities to internal teams and customers.
• Orchestrate multi-step pipeline work with workflow engines (Temporal) and event-driven dispatch (NATS/JetStream).
• Collaborate in a sprint-based cycle with product and science to turn analytical workloads into production features.

What Will Help You Succeed

Engineering fundamentals

• 5+ years writing production software, with deep Python (3.10+, async/await, type hints; pandas, SQLAlchemy, Pydantic).
• Built resilient, observable ETL/ELT pipelines that ingest, transform, and validate data at scale.
• API/backend design: GraphQL and/or REST contracts, versioning, and ergonomics other engineers actually enjoy using.
• PostgreSQL depth - schema design, query optimization; comfortable with both ORM and raw SQL.

Systems & tooling

• Event-driven and workflow-orchestrated systems (Temporal, NATS / Kafka, or similar).
• Data validation / quality frameworks, and a habit of designing for correctness and debuggability.

Nice to have

• Plugin / extension development (Apache NiFi or similar) and fluency with AI coding assistants as part of your workflow.
• Performance-sensitive work in a systems language (Rust, C++) - graph / lineage modeling; connector ecosystems.

The Role Is Right For You If

• You like turning a hard product vision into clean, composable systems others build on.
• You build and ship alongside the team, and you treat pipeline correctness as a feature.