Software Engineering Lead - Data Services

**Read this first.

This role is not for you if

**

• You want to manage people more than write code. This role is 80% hands-on engineering, 20% leading the team
• **You've never had engineers formally reporting to you.** Mentoring or acting as a tech lead without direct reports doesn't count
• **You haven't built production services with FastAPI**
• You haven't written production code in the last year
• Your AI experience is wrapping an LLM API in a prototype, not running agents in production with evals and traces

You've never built the harness agents run inside

tool calling, MCP servers, eval suites

• You haven't run services handling millions of API calls
• Your experience is mostly services or consulting delivery, without long-term ownership of a product

Firmable sells company and people data to sales teams across Asia Pacific and the US, and we're taking it worldwide. Data Services builds the APIs, services and agents behind every Firmable product, and this role runs it.

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## What you'll work on

You'll lead one engineering pod.

• Python service and API architecture on FastAPI, Pydantic and Logfire

The agent runtime the team builds on

tool calling, MCP servers, structured-output validation, bounded loops, human checkpoints and replayable traces

• Fast decision APIs built on small typed models, next to LLM agents for the work that needs real reasoning

Evals in CI

labelled sets, judge calibration, multi-turn and trajectory tests, drift detection

Reliability at scale

caching, rate limits, cost ceilings, retries and graceful degradation

• Architecture and code review across both pods

## Must haves

• 7–10 years of backend engineering
• Expert Python, plus data modelling across SQL and NoSQL
• RESTful services you designed and ran at scale

**Nice to have

** Braintrust, Inspect or Promptfoo

• Logfire or OpenTelemetry
• Claude Agent SDK, Pydantic AI or LangGraph
• AWS or GCP at scale
• Snowflake
• B2B data
• startup experience
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## How we build

We write code with coding agents like Claude Code by default, and engineers spend their time on design, review and evals. In production we pick the model for the job: frontier LLMs for messy extraction and reasoning, small typed decision models when the answer is a yes/no, a choice or a score, and MCP servers and agent SDKs when a model needs tools. When something new ships, we run it against our evals that week. Every LLM call is logged with its prompt version, model and cost.

Small teams, no layers, weekly releases moving to daily. No fixed hours, no handholding.

## The deal

Competitive base and meaningful equity. The next version of our services and agent platform is yours to design.

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_Firmable is an equal opportunity employer. We believe diverse teams build better products._