Engineering Manager, Serving​/API

Positron is seeking an Engineering Manager to lead Production Platform and Orchestration within our Upstack Engineering organization. This team owns the software and operating practices that provision, deploy, observe, upgrade, and reliably operate Positron systems in production. You will inherit a technically strong core team and help it grow into a durable organization capable of supporting a fleet that is expanding by several multiples.

This is a technical leadership role with real operational accountability. You will set direction, build the team, create clear ownership, and improve the systems and processes behind fleet orchestration, deployment lifecycle, observability, incident response, release automation, and production reliability. You will work closely with serving and API, model enablement, compiler and runtime, hardware, customer-facing, and data center partners.

The strongest candidate will combine systems depth with organizational judgment, moving comfortably between architecture, delivery, incidents, people development, and cross-functional planning. This description intentionally emphasizes outcomes and ownership over a fixed organizational chart. As the fleet and customer base grow, the function may develop dedicated groups for fleet orchestration and capacity, deployment lifecycle, reliability and observability, data center operations, customer production operations, and operational tooling.

We are seeking an Engineering Manager to lead Serving/API. This team owns the software between a customer's API request and the tokens Positron accelerators generate: what the model sees, and how its output becomes a correct, well-formed response. You will lead a strong team and grow it as Positron adds models, modalities, and serving capabilities.

The team owns:

• The OpenAI-compatible serving layer. HTTP endpoints, request validation, SSE streaming, usage accounting and API-spec fidelity.
• Tokenization and chat templates. Hugging Face tokenizers, chat-template rendering, and model-specific conversation formats such as OpenAI Harmony for GPT-OSS.
• Tool calling and structured output. Tool-schema handling, tool-call parsing and serialization, and grammar-constrained decoding (ll guidance) for JSON and function calls.
• Reasoning and budgets. Reasoning-channel parsing, reasoning-effort controls, token limits and per-request budgets.
• Speculative decoding. The request-side plumbing for draft models and draft trees, acceptance metrics, and the policies that decide when speculation pays off.
• New modalities and frameworks. Vision-language model (VLM) input handling and integration paths with SGLang-style serving.

This is a technical leadership role with real product accountability. You will set direction, build the team, create clear ownership, and improve the systems behind API fidelity, tool calling, reasoning, speculative decoding, and new-model readiness. You will work closely with Production Platform and Orchestration, Compiler/Executor, hardware, and customer-facing partners.

• Lead, coach, and grow a team of engineers spanning API serving, tokenization, structured generation, and model integration.
• Establish a clear technical and organizational roadmap for the serving layer: API surface, chat templates, tool calling, reasoning, budgets, and new-model support.
• Ensure API fidelity:
  OpenAI-compatible behavior, streaming, usage accounting, and error handling that customers and their tooling can rely on.
• Lead reasoning-model support and request budgets, including reasoning formats, reasoning-effort controls, token limits, and per-request accounting.
• Partner with Compiler/Executor on speculative decoding: draft-model integration, request-side plumbing,…