Field Application Engineer

TERASi; Stockholms kommun; Hybrid; SEK 850,000 - 1,150,000; Full time

Benefits offered by this job

Equity stake

Direct CEO mentorship

Job summary

TERASi in Stockholm, Sweden seeks a hands-on engineer to bridge customers and product. You will craft end-to-end PoCs that integrate RF hardware, software stacks, and data pipelines, traveling to customer sites across Europe and the US as needed. You’ll shape solutions directly with the CEO and define patterns for the product roadmap.

The role blends hardware comfort with software fluency, and requires the ability to deliver demos under time pressure while maintaining a customer-centric approach.

Qualifications

• Proven end-to-end development experience across software and hardware interfaces.
• Comfort with RF, sensors, embedded systems and test equipment.
• Strong Python programming and data pipeline familiarity.
• Ability to engage with senior customers and earn trust without scripts.
• Demonstrated ability to ship demos under time pressure.
• Comfort working in ambiguous customer problems and extracting requirements.

Responsibilities

• Sit with customers to understand real needs beyond initial requests.
• Scope and build PoCs and demos integrating our RU with customer systems.
• Perform end-to-end integration: hardware, software, and data flows.
• Travel to customer sites in the US and Europe for field demos.
• Feed learnings back into the product roadmap based on patterns observed.
• Collaborate with the CEO on high-priority opportunities with autonomy.

Skills

Full-stack engineering

Hardware comfort

Python

Customer-facing presence

Shipping mindset

Ambiguity tolerance

Tools

MAVLink

Edge processing

AI/ML inference

Job description

Why this role exists

We build Radio Units (RUs) that work as high-speed, secure, jam-resistant data pipelines for defence and dual-use applications — the connective tissue for UAV C2, deployable 5G, and tactical awareness systems.

Why this role exists

We build Radio Units (RUs) that work as high-speed, secure, jam-resistant data pipelines for defence and dual-use applications — the connective tissue for UAV C2, deployable 5G, and tactical awareness systems. Our pipeline is full of customers — defence primes, armed forces, industrial operators — who are excited about what our RU could do for them. The bottleneck isn't interest. It's that we don't have enough hands to sit with those customers, understand their actual problem, build something that proves it, and spot the patterns before anyone else does so we can feed them into our product roadmap. That's the job. You'll be the person who turns "this is interesting, let's talk again" into "we've seen it work, here's a contract.

What You'll Actually Do

• Sit in rooms with customers — sometimes a defence prime's systems architect, sometimes a signals officer, sometimes both — and figure out what they actually need (which is rarely what they first asked for).
• Scope and build PoCs and demos that integrate our RU with whatever the customer cares about: cameras, radars, microphones, ground stations on one end; data lakes, AI tooling, C2 software on the other.
• Do the integration work end-to-end. That means wiring a physical kit on Monday, debugging a MAVLink message on Tuesday, writing Python to push sensor data into a customer's stack on Wednesday, and demoing the whole thing on Thursday.
• Travel to customer sites in the US and across Europe. Sometimes you'll deploy and run a demo in the field. Sometimes you'll spend a week embedded with a prime's engineering team.
• Feed what you learn back into product. The patterns you find — the integrations customers keep asking for, the operational constraints that keep showing up — are how we figure out what to build next.
• Work directly with our CEO on the highest-priority opportunities. Until our CCO is in seat, you'll be operating with a lot of autonomy and short feedback loops.

What We're Looking For

This is a hybrid role — equally happy soldering a cable and writing the Python that ingests what comes out of it. We don't expect you to have done all of the below, but you should be credibly strong on most of it:

• Full-stack engineering instincts. You've built things end-to-end and you don't wait for someone else to define the interface.
• Hardware comfort. RF, comms, sensors, embedded systems — you've been around it. You're not scared of an oscilloscope or a radio link budget.
• Software fluency. Python is table stakes. You've worked with data pipelines, APIs, and at least one of the things our customers care about: drone autopilots (MAVLink, STANAG 4586), sensor fusion, edge processing, AI/ML inference at the edge, ground control stations.
• Customer-facing presence. You can sit in front of a colonel, a procurement officer, or a prime's chief engineer and earn their trust. You don't need a script.
• A bias for shipping. You've built demos and prototypes under time pressure. You know the difference between "demo-good" and "production-good" and you make the right call for the situation.
• Comfort with ambiguity. Customer says something vague. You don't wait for it to get clearer — you go figure out what they actually mean.

We're open on seniority. If you're 4 years in and exceptional, we want to talk. If you're 10 years in and want to be hands-on at a stage where what you build defines the company, we want to talk.

Background that fits

This Is Illustrative, Not a Checklist

• Integration engineers from drone, robotics, or autonomy companies (typically Payload Integration, Flight Software, Ground Systems, or Integration Engineers at Auterion, Tekever, Quantum Systems, and similar) who've done real customer integration work.
• Forward Deployed / Mission Engineers from neo-defence companies (typically FDEs or FDSEs at Palantir; Mission Operations, Mission Software, or Mission Deployment Engineers at Anduril; and equivalent customer-facing engineers at Shield AI, Tekever, or similar).
• Engineers from RF, comms, or satellite companies (typically Firmware, Baseband, RF Systems, or Systems Integration Engineers at Bittium, Sivers Semiconductors, Gapwaves, Ericsson, Mynaric, or comms divisions at Saab, Leonardo, L3Harris, and Thales).
• Ex-military signals, EW, or comms officers (Signals Officers, Communications Officers, Electronic Warfare Officers, or Combat Systems Engineers) who've moved into engineering roles and miss being close to operators.
• Engineers from defence primes' rapid prototyping or skunkworks teams (typically Capability, Systems, Prototyping, or Applied Research Engineers) who are tired of the pace.

What We're Not Looking For

• Solutions Engineers from SaaS who are used to a defined demo script and a clean handoff to a CSM.
• Pure researchers or lab engineers who haven't shipped to real users.
• Career salespeople with a technical veneer.
• People who need a fully scoped backlog before they can start.

What You'll Get

• A seat at the table while we build the commercial function from scratch. The PoCs you build will define our product roadmap and our first multi-million-euro contracts.
• Direct working relationship with the CEO and the rest of the founding team.
• Real customers from week one. We have live opportunities in UAV C2 and deployable 5G that need an FDE on them today.
• Equity that reflects the impact. You'll be one of the first commercial hires.
• Salary commensurate with experience — we'll calibrate to your level and the market.

TERASi is a deeptech startup based in Stockholm, Sweden which offers unique components and packaging for high-frequency wireless applications. TERASi’s technology builds upon academic research at KTH Royal Institute of Technology and years of internal R&D. The company designs and manufactures all components from its Stockholm headquarters and now embarks upon a mission to scale their technology and bring it to mass markets.