Senior Software Engineer

TechTree; Paris; Hybrid; EUR 85,000 - 105,000; Full time

Benefits offered by this job

Equity

Relocation sponsorship

Job summary

TechTree is hiring a pragmatic software engineering generalist to join a fast-moving, early-stage team between Paris and Warsaw. You will work closely with the founders to iterate on prototypes, implementing audio streaming and real-time voice systems.

Fluency in French and English is essential to communicate across the team and with customers in Europe. Relocation sponsorship is available; compensation depends on experience, with an expected range of €85-105K plus equity, and an in-office

Qualifications

• Experience as a pragmatic software engineer in a fast-moving environment.
• Ability to explain complex systems clearly to non-technical stakeholders.
• Capable of building from zero and delivering with hands-on execution.

Responsibilities

• Iterate quickly on prototypes with early customers.
• Develop and improve audio streaming and real-time voice components.
• Collaborate with founders to ship robust software under stealth.

Skills

Software engineering generalist

Audio streaming

Real-time voice systems

French

English

Job description

A European defence startup based between Paris and Warsaw, building modern software tailored for hostile environments. Our customers include European military and police units. We are in stealth but have already been recognised as one of France's top 20 seed companies. Backed by Europe's leading defence VC and angels including the founders of Cloudflare, Quantum Systems, and ElevenLabs.

Our founding team includes two early Cloudflare employees and a former GIGN commander (French special forces). Other team members include ex-Googlers, Thales PhDs, and ex-founders. We do not work on weapons systems or hardware products.

What you’ll work on

You’ll work closely with the founders to iterate quickly on deployments of our prototypes with early customers.

You should be prepared to get your hands dirty with bespoke audio streaming tech and real-time voice systems.

Who we’re looking for

A pragmatic, product-minded software engineering generalist with strong execution skills and a desire to build from zero. You thrive in ambiguous, fast-moving environments, can explain complex technical systems in simple ways, and speak French and English. You want your work to have real-world impact, helping those who serve.

None of the below is a blocker, but you might be especially excited about this if you:

Have worked with LLMs, or built pipelines

Are comfortable diving into audio processing and low-latency systems

Have worked in on-prem environments

Have implemented AI systems in resource-constrained environments

Have experience working with armed forces

Location & Compensation

We’re currently hiring in Paris and Warsaw

We have an in‑office culture and can sponsor relocation, if required

Compensation depends on experience; expected range €85-105K + equity