Senior Software Engineer

Synaxia Group; New York (NY); Hybrid; USD 190,000 - 220,000; Full time

Benefits offered by this job

Hybrid work in NYC

Competitive salary

Job summary

Synaxia Group in New York is seeking a Senior Backend Engineer to own the health data layer and external APIs. You’ll join a fast-growing healthtech scaleup building the platform behind AI-enabled medical practice, with hybrid work in New York and ownership of critical data pipelines.

You would design, expose and evolve external APIs, while guiding platform primitives and ingestion frameworks. A strong background in production backend systems and health data is essential for this senior role.

Qualifications

• 6+ years building production backend systems.
• Experience designing external-facing APIs.
• Strong data modelling for health data, time-series, or high-frequency signals.
• Comfort in a fast-paced greenfield environment where you set the direction.

Responsibilities

• Design and evolve the external API and embedded product layer with versioning and stability for enterprise clients.
• Own critical platform primitives on Platform & Integrations, building the health data platform that ingests, reconciles and exposes data across the product.
• Build pluggable ingestion frameworks that normalise third-party data into canonical models for easy partner onboarding.
• Collaborate with partner engineering teams on embedded integrations where the product sits inside their apps.
• Shape the backend architecture as new integration patterns and client requirements emerge every few months.

Skills

6+ years backend

API design

health data modelling

greenfield architecture

Job description

Are you the backend engineer people trust when the data gets messy?

Senior Backend Engineer, Health Data & External APIs · New York (hybrid) · $190K–$220K

You’ve spent 6+ years building production backend systems, and you’ve shipped APIs that customers and partners actually depend on. This is a senior backend role at a well-funded healthtech scaleup in New York, building the platform behind an AI-first medical practice. You’ll own the health data layer that pulls wearable, medication, lab and EHR data together, and you’ll design the external APIs that enterprise healthcare partners build on. It’s greenfield, the ownership is real, and the architecture you set will still be standing in three years.

The company was founded in 2023, has around 90 people, and has raised over $37M from top-tier VC firms. It’s already working with leading healthcare organisations and expects to serve hundreds of thousands of patients within the next year. The founding team has senior roles from Harvard Medical School, Mass General, UCSF, the MIT Media Lab, NVIDIA and Mount Sinai.

The role

• Design and evolve the external API and embedded product layer, with versioning and stability you’d be happy to put in front of enterprise clients.
• Own critical platform primitives on the Platform & Integrations team, building the health data platform that ingests, reconciles and exposes data across the whole product.
• Build pluggable ingestion frameworks that normalise third-party data into canonical models, so onboarding a new partner means writing an adapter, not rebuilding the pipeline.
• Work directly with partner engineering teams on embedded integrations, where the product sits inside their apps.
• Shape the backend architecture as new integration patterns and client requirements show up every few months.

What you bring

• 6+ years building production backend systems, ideally at high-growth startups
• Experience designing and maintaining external-facing or public APIs
• Strong data modelling instincts, especially around health data, time-series or high-frequency signals
• Comfort in a fast-paced greenfield environment where you set the direction

Bonus: Series B–D startup experience, or healthcare and health tech.

What you get

• Hybrid, with Tuesday to Thursday in the Flatiron office
• Full-time, working alongside a sharp, collaborative team
• Values built on humility, excellent work and tackling problems that matter

No visa sponsorship. You’ll need to be a US citizen or Green Card holder.